Hello,
syzbot found the following issue on:
HEAD commit: 950b879b7f02 riscv: Fixup race condition on PG_dcache_clea..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
console output: https://syzkaller.appspot.com/x/log.txt?x=10c4c1f7c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=ecebece1b90c0342
dashboard link: https://syzkaller.appspot.com/bug?extid=01e9a564dc6b3289cea3
compiler: riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: riscv64
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
==================================================================
BUG: KASAN: stack-out-of-bounds in walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
Read of size 8 at addr ff200000030a79b0 by task syz-executor.1/7894
CPU: 0 PID: 7894 Comm: syz-executor.1 Tainted: G W 6.2.0-rc1-syzkaller #0
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff8000b9ea>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121
[<ffffffff83402b96>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127
[<ffffffff83442726>] __dump_stack lib/dump_stack.c:88 [inline]
[<ffffffff83442726>] dump_stack_lvl+0xe0/0x14c lib/dump_stack.c:106
[<ffffffff83409674>] print_address_description mm/kasan/report.c:306 [inline]
[<ffffffff83409674>] print_report+0x1e4/0x4c0 mm/kasan/report.c:417
[<ffffffff804ead14>] kasan_report+0xb8/0xe6 mm/kasan/report.c:517
[<ffffffff804ebea4>] check_region_inline mm/kasan/generic.c:183 [inline]
[<ffffffff804ebea4>] __asan_load8+0x7e/0xa6 mm/kasan/generic.c:256
[<ffffffff8000b782>] walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
[<ffffffff8000bc66>] arch_stack_walk+0x2c/0x3c arch/riscv/kernel/stacktrace.c:154
[<ffffffff80190822>] stack_trace_save_tsk+0x14a/0x1bc kernel/stacktrace.c:150
[<ffffffff80697822>] proc_pid_stack+0x146/0x1ee fs/proc/base.c:456
[<ffffffff80698bb0>] proc_single_show+0x9c/0x148 fs/proc/base.c:777
[<ffffffff805af580>] traverse.part.0+0x74/0x2ca fs/seq_file.c:111
[<ffffffff805aff02>] traverse fs/seq_file.c:101 [inline]
[<ffffffff805aff02>] seq_read_iter+0x72c/0x934 fs/seq_file.c:195
[<ffffffff805b0224>] seq_read+0x11a/0x16e fs/seq_file.c:162
[<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:756 [inline]
[<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:743 [inline]
[<ffffffff805453ea>] do_iter_read+0x324/0x3c2 fs/read_write.c:798
[<ffffffff805455f8>] vfs_readv+0xfe/0x166 fs/read_write.c:916
[<ffffffff80549c66>] do_preadv fs/read_write.c:1008 [inline]
[<ffffffff80549c66>] __do_sys_preadv fs/read_write.c:1058 [inline]
[<ffffffff80549c66>] sys_preadv+0x182/0x1fa fs/read_write.c:1053
[<ffffffff80005ff6>] ret_from_syscall+0x0/0x2
The buggy address belongs to the virtual mapping at
[ff200000030a0000, ff200000030a9000) created by:
kernel_clone+0xee/0x914 kernel/fork.c:2681
The buggy address belongs to the physical page:
page:ff1c0000024e5f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9397c
memcg:ff6000000ffd7202
flags: 0xffe000000000000(node=0|zone=0|lastcpupid=0x7ff)
raw: 0ffe000000000000 0000000000000000 0000000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ff6000000ffd7202
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 7873, tgid 7873 (syz-executor.1), ts 4012100669800, free_ts 4010400733200
__set_page_owner+0x32/0x182 mm/page_owner.c:190
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0xf8/0x11a mm/page_alloc.c:2524
prep_new_page mm/page_alloc.c:2531 [inline]
get_page_from_freelist+0xc0e/0x1118 mm/page_alloc.c:4283
__alloc_pages+0x1b0/0x165a mm/page_alloc.c:5549
alloc_pages+0x132/0x25e mm/mempolicy.c:2286
vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
__vmalloc_area_node mm/vmalloc.c:3057 [inline]
__vmalloc_node_range+0x81c/0xdb4 mm/vmalloc.c:3227
alloc_thread_stack_node kernel/fork.c:311 [inline]
dup_task_struct kernel/fork.c:987 [inline]
copy_process+0x210e/0x4068 kernel/fork.c:2097
kernel_clone+0xee/0x914 kernel/fork.c:2681
__do_sys_clone+0xec/0x120 kernel/fork.c:2822
sys_clone+0x32/0x44 kernel/fork.c:2790
ret_from_syscall+0x0/0x2
page last free stack trace:
__reset_page_owner+0x4a/0xf8 mm/page_owner.c:148
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1446 [inline]
free_pcp_prepare+0x254/0x48e mm/page_alloc.c:1496
free_unref_page_prepare mm/page_alloc.c:3369 [inline]
free_unref_page_list+0x11e/0x736 mm/page_alloc.c:3510
release_pages+0x85a/0xbb2 mm/swap.c:1076
free_pages_and_swap_cache+0x76/0x88 mm/swap_state.c:311
tlb_batch_pages_flush+0x86/0x10c mm/mmu_gather.c:97
tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
tlb_flush_mmu mm/mmu_gather.c:299 [inline]
tlb_finish_mmu+0xcc/0x280 mm/mmu_gather.c:391
exit_mmap+0x190/0x686 mm/mmap.c:3096
__mmput+0x98/0x290 kernel/fork.c:1207
mmput+0x74/0x88 kernel/fork.c:1229
exit_mm kernel/exit.c:563 [inline]
do_exit+0x602/0x17be kernel/exit.c:854
do_group_exit+0x8e/0x15e kernel/exit.c:1012
__do_sys_exit_group kernel/exit.c:1023 [inline]
__wake_up_parent+0x0/0x4a kernel/exit.c:1021
ret_from_syscall+0x0/0x2
Memory state around the buggy address:
ff200000030a7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ff200000030a7900: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2
>ff200000030a7980: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
^
ff200000030a7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ff200000030a7a80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email protected].
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to change bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
On Tue, 2 May 2023 at 09:05, syzbot
<[email protected]> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 950b879b7f02 riscv: Fixup race condition on PG_dcache_clea..
> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> console output: https://syzkaller.appspot.com/x/log.txt?x=10c4c1f7c80000
> kernel config: https://syzkaller.appspot.com/x/.config?x=ecebece1b90c0342
> dashboard link: https://syzkaller.appspot.com/bug?extid=01e9a564dc6b3289cea3
> compiler: riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> userspace arch: riscv64
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
>
> ==================================================================
> BUG: KASAN: stack-out-of-bounds in walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> Read of size 8 at addr ff200000030a79b0 by task syz-executor.1/7894
>
> CPU: 0 PID: 7894 Comm: syz-executor.1 Tainted: G W 6.2.0-rc1-syzkaller #0
> Hardware name: riscv-virtio,qemu (DT)
> Call Trace:
> [<ffffffff8000b9ea>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121
> [<ffffffff83402b96>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127
> [<ffffffff83442726>] __dump_stack lib/dump_stack.c:88 [inline]
> [<ffffffff83442726>] dump_stack_lvl+0xe0/0x14c lib/dump_stack.c:106
> [<ffffffff83409674>] print_address_description mm/kasan/report.c:306 [inline]
> [<ffffffff83409674>] print_report+0x1e4/0x4c0 mm/kasan/report.c:417
> [<ffffffff804ead14>] kasan_report+0xb8/0xe6 mm/kasan/report.c:517
> [<ffffffff804ebea4>] check_region_inline mm/kasan/generic.c:183 [inline]
> [<ffffffff804ebea4>] __asan_load8+0x7e/0xa6 mm/kasan/generic.c:256
> [<ffffffff8000b782>] walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
+riscv maintainers
I think this is an issue in riscv stack walking.
If it's imprecise or walks stacks of running tasks, it needs to use
READ_ONCE_NOCHECK.
#syz set subsystems: riscv
> [<ffffffff8000bc66>] arch_stack_walk+0x2c/0x3c arch/riscv/kernel/stacktrace.c:154
> [<ffffffff80190822>] stack_trace_save_tsk+0x14a/0x1bc kernel/stacktrace.c:150
> [<ffffffff80697822>] proc_pid_stack+0x146/0x1ee fs/proc/base.c:456
> [<ffffffff80698bb0>] proc_single_show+0x9c/0x148 fs/proc/base.c:777
> [<ffffffff805af580>] traverse.part.0+0x74/0x2ca fs/seq_file.c:111
> [<ffffffff805aff02>] traverse fs/seq_file.c:101 [inline]
> [<ffffffff805aff02>] seq_read_iter+0x72c/0x934 fs/seq_file.c:195
> [<ffffffff805b0224>] seq_read+0x11a/0x16e fs/seq_file.c:162
> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:756 [inline]
> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:743 [inline]
> [<ffffffff805453ea>] do_iter_read+0x324/0x3c2 fs/read_write.c:798
> [<ffffffff805455f8>] vfs_readv+0xfe/0x166 fs/read_write.c:916
> [<ffffffff80549c66>] do_preadv fs/read_write.c:1008 [inline]
> [<ffffffff80549c66>] __do_sys_preadv fs/read_write.c:1058 [inline]
> [<ffffffff80549c66>] sys_preadv+0x182/0x1fa fs/read_write.c:1053
> [<ffffffff80005ff6>] ret_from_syscall+0x0/0x2
>
> The buggy address belongs to the virtual mapping at
> [ff200000030a0000, ff200000030a9000) created by:
> kernel_clone+0xee/0x914 kernel/fork.c:2681
>
> The buggy address belongs to the physical page:
> page:ff1c0000024e5f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9397c
> memcg:ff6000000ffd7202
> flags: 0xffe000000000000(node=0|zone=0|lastcpupid=0x7ff)
> raw: 0ffe000000000000 0000000000000000 0000000000000122 0000000000000000
> raw: 0000000000000000 0000000000000000 00000001ffffffff ff6000000ffd7202
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 7873, tgid 7873 (syz-executor.1), ts 4012100669800, free_ts 4010400733200
> __set_page_owner+0x32/0x182 mm/page_owner.c:190
> set_page_owner include/linux/page_owner.h:31 [inline]
> post_alloc_hook+0xf8/0x11a mm/page_alloc.c:2524
> prep_new_page mm/page_alloc.c:2531 [inline]
> get_page_from_freelist+0xc0e/0x1118 mm/page_alloc.c:4283
> __alloc_pages+0x1b0/0x165a mm/page_alloc.c:5549
> alloc_pages+0x132/0x25e mm/mempolicy.c:2286
> vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
> __vmalloc_area_node mm/vmalloc.c:3057 [inline]
> __vmalloc_node_range+0x81c/0xdb4 mm/vmalloc.c:3227
> alloc_thread_stack_node kernel/fork.c:311 [inline]
> dup_task_struct kernel/fork.c:987 [inline]
> copy_process+0x210e/0x4068 kernel/fork.c:2097
> kernel_clone+0xee/0x914 kernel/fork.c:2681
> __do_sys_clone+0xec/0x120 kernel/fork.c:2822
> sys_clone+0x32/0x44 kernel/fork.c:2790
> ret_from_syscall+0x0/0x2
> page last free stack trace:
> __reset_page_owner+0x4a/0xf8 mm/page_owner.c:148
> reset_page_owner include/linux/page_owner.h:24 [inline]
> free_pages_prepare mm/page_alloc.c:1446 [inline]
> free_pcp_prepare+0x254/0x48e mm/page_alloc.c:1496
> free_unref_page_prepare mm/page_alloc.c:3369 [inline]
> free_unref_page_list+0x11e/0x736 mm/page_alloc.c:3510
> release_pages+0x85a/0xbb2 mm/swap.c:1076
> free_pages_and_swap_cache+0x76/0x88 mm/swap_state.c:311
> tlb_batch_pages_flush+0x86/0x10c mm/mmu_gather.c:97
> tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
> tlb_flush_mmu mm/mmu_gather.c:299 [inline]
> tlb_finish_mmu+0xcc/0x280 mm/mmu_gather.c:391
> exit_mmap+0x190/0x686 mm/mmap.c:3096
> __mmput+0x98/0x290 kernel/fork.c:1207
> mmput+0x74/0x88 kernel/fork.c:1229
> exit_mm kernel/exit.c:563 [inline]
> do_exit+0x602/0x17be kernel/exit.c:854
> do_group_exit+0x8e/0x15e kernel/exit.c:1012
> __do_sys_exit_group kernel/exit.c:1023 [inline]
> __wake_up_parent+0x0/0x4a kernel/exit.c:1021
> ret_from_syscall+0x0/0x2
>
> Memory state around the buggy address:
> ff200000030a7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ff200000030a7900: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2
> >ff200000030a7980: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
> ^
> ff200000030a7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ff200000030a7a80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
> ==================================================================
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at [email protected].
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want to change bug's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the bug is a duplicate of another bug, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/00000000000084706805fab08e27%40google.com.
On 5/2/23 09:15, Dmitry Vyukov wrote:
> On Tue, 2 May 2023 at 09:05, syzbot
> <[email protected]> wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 950b879b7f02 riscv: Fixup race condition on PG_dcache_clea..
>> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
>> console output: https://syzkaller.appspot.com/x/log.txt?x=10c4c1f7c80000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=ecebece1b90c0342
>> dashboard link: https://syzkaller.appspot.com/bug?extid=01e9a564dc6b3289cea3
>> compiler: riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>> userspace arch: riscv64
>>
>> Unfortunately, I don't have any reproducer for this issue yet.
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: [email protected]
>>
>> ==================================================================
>> BUG: KASAN: stack-out-of-bounds in walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
>> Read of size 8 at addr ff200000030a79b0 by task syz-executor.1/7894
>>
>> CPU: 0 PID: 7894 Comm: syz-executor.1 Tainted: G W 6.2.0-rc1-syzkaller #0
>> Hardware name: riscv-virtio,qemu (DT)
>> Call Trace:
>> [<ffffffff8000b9ea>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121
>> [<ffffffff83402b96>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127
>> [<ffffffff83442726>] __dump_stack lib/dump_stack.c:88 [inline]
>> [<ffffffff83442726>] dump_stack_lvl+0xe0/0x14c lib/dump_stack.c:106
>> [<ffffffff83409674>] print_address_description mm/kasan/report.c:306 [inline]
>> [<ffffffff83409674>] print_report+0x1e4/0x4c0 mm/kasan/report.c:417
>> [<ffffffff804ead14>] kasan_report+0xb8/0xe6 mm/kasan/report.c:517
>> [<ffffffff804ebea4>] check_region_inline mm/kasan/generic.c:183 [inline]
>> [<ffffffff804ebea4>] __asan_load8+0x7e/0xa6 mm/kasan/generic.c:256
>> [<ffffffff8000b782>] walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> +riscv maintainers
>
> I think this is an issue in riscv stack walking.
> If it's imprecise or walks stacks of running tasks, it needs to use
> READ_ONCE_NOCHECK.
>
> #syz set subsystems: riscv
This fix was merged in 6.3: commit 76950340cf03 ("riscv: Use
READ_ONCE_NOCHECK in imprecise unwinding stack mode").
>
>
>> [<ffffffff8000bc66>] arch_stack_walk+0x2c/0x3c arch/riscv/kernel/stacktrace.c:154
>> [<ffffffff80190822>] stack_trace_save_tsk+0x14a/0x1bc kernel/stacktrace.c:150
>> [<ffffffff80697822>] proc_pid_stack+0x146/0x1ee fs/proc/base.c:456
>> [<ffffffff80698bb0>] proc_single_show+0x9c/0x148 fs/proc/base.c:777
>> [<ffffffff805af580>] traverse.part.0+0x74/0x2ca fs/seq_file.c:111
>> [<ffffffff805aff02>] traverse fs/seq_file.c:101 [inline]
>> [<ffffffff805aff02>] seq_read_iter+0x72c/0x934 fs/seq_file.c:195
>> [<ffffffff805b0224>] seq_read+0x11a/0x16e fs/seq_file.c:162
>> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:756 [inline]
>> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:743 [inline]
>> [<ffffffff805453ea>] do_iter_read+0x324/0x3c2 fs/read_write.c:798
>> [<ffffffff805455f8>] vfs_readv+0xfe/0x166 fs/read_write.c:916
>> [<ffffffff80549c66>] do_preadv fs/read_write.c:1008 [inline]
>> [<ffffffff80549c66>] __do_sys_preadv fs/read_write.c:1058 [inline]
>> [<ffffffff80549c66>] sys_preadv+0x182/0x1fa fs/read_write.c:1053
>> [<ffffffff80005ff6>] ret_from_syscall+0x0/0x2
>>
>> The buggy address belongs to the virtual mapping at
>> [ff200000030a0000, ff200000030a9000) created by:
>> kernel_clone+0xee/0x914 kernel/fork.c:2681
>>
>> The buggy address belongs to the physical page:
>> page:ff1c0000024e5f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9397c
>> memcg:ff6000000ffd7202
>> flags: 0xffe000000000000(node=0|zone=0|lastcpupid=0x7ff)
>> raw: 0ffe000000000000 0000000000000000 0000000000000122 0000000000000000
>> raw: 0000000000000000 0000000000000000 00000001ffffffff ff6000000ffd7202
>> page dumped because: kasan: bad access detected
>> page_owner tracks the page as allocated
>> page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 7873, tgid 7873 (syz-executor.1), ts 4012100669800, free_ts 4010400733200
>> __set_page_owner+0x32/0x182 mm/page_owner.c:190
>> set_page_owner include/linux/page_owner.h:31 [inline]
>> post_alloc_hook+0xf8/0x11a mm/page_alloc.c:2524
>> prep_new_page mm/page_alloc.c:2531 [inline]
>> get_page_from_freelist+0xc0e/0x1118 mm/page_alloc.c:4283
>> __alloc_pages+0x1b0/0x165a mm/page_alloc.c:5549
>> alloc_pages+0x132/0x25e mm/mempolicy.c:2286
>> vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
>> __vmalloc_area_node mm/vmalloc.c:3057 [inline]
>> __vmalloc_node_range+0x81c/0xdb4 mm/vmalloc.c:3227
>> alloc_thread_stack_node kernel/fork.c:311 [inline]
>> dup_task_struct kernel/fork.c:987 [inline]
>> copy_process+0x210e/0x4068 kernel/fork.c:2097
>> kernel_clone+0xee/0x914 kernel/fork.c:2681
>> __do_sys_clone+0xec/0x120 kernel/fork.c:2822
>> sys_clone+0x32/0x44 kernel/fork.c:2790
>> ret_from_syscall+0x0/0x2
>> page last free stack trace:
>> __reset_page_owner+0x4a/0xf8 mm/page_owner.c:148
>> reset_page_owner include/linux/page_owner.h:24 [inline]
>> free_pages_prepare mm/page_alloc.c:1446 [inline]
>> free_pcp_prepare+0x254/0x48e mm/page_alloc.c:1496
>> free_unref_page_prepare mm/page_alloc.c:3369 [inline]
>> free_unref_page_list+0x11e/0x736 mm/page_alloc.c:3510
>> release_pages+0x85a/0xbb2 mm/swap.c:1076
>> free_pages_and_swap_cache+0x76/0x88 mm/swap_state.c:311
>> tlb_batch_pages_flush+0x86/0x10c mm/mmu_gather.c:97
>> tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
>> tlb_flush_mmu mm/mmu_gather.c:299 [inline]
>> tlb_finish_mmu+0xcc/0x280 mm/mmu_gather.c:391
>> exit_mmap+0x190/0x686 mm/mmap.c:3096
>> __mmput+0x98/0x290 kernel/fork.c:1207
>> mmput+0x74/0x88 kernel/fork.c:1229
>> exit_mm kernel/exit.c:563 [inline]
>> do_exit+0x602/0x17be kernel/exit.c:854
>> do_group_exit+0x8e/0x15e kernel/exit.c:1012
>> __do_sys_exit_group kernel/exit.c:1023 [inline]
>> __wake_up_parent+0x0/0x4a kernel/exit.c:1021
>> ret_from_syscall+0x0/0x2
>>
>> Memory state around the buggy address:
>> ff200000030a7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>> ff200000030a7900: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2
>>> ff200000030a7980: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
>> ^
>> ff200000030a7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>> ff200000030a7a80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
>> ==================================================================
>>
>>
>> ---
>> This report is generated by a bot. It may contain errors.
>> See https://goo.gl/tpsmEJ for more information about syzbot.
>> syzbot engineers can be reached at [email protected].
>>
>> syzbot will keep track of this issue. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>>
>> If the bug is already fixed, let syzbot know by replying with:
>> #syz fix: exact-commit-title
>>
>> If you want to change bug's subsystems, reply with:
>> #syz set subsystems: new-subsystem
>> (See the list of subsystem names on the web dashboard)
>>
>> If the bug is a duplicate of another bug, reply with:
>> #syz dup: exact-subject-of-another-report
>>
>> If you want to undo deduplication, reply with:
>> #syz undup
>>
>> --
>> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
>> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
>> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/00000000000084706805fab08e27%40google.com.
> _______________________________________________
> linux-riscv mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-riscv
On Tue, 2 May 2023 at 14:02, Alexandre Ghiti <[email protected]> wrote:
>
> On 5/2/23 09:15, Dmitry Vyukov wrote:
> > On Tue, 2 May 2023 at 09:05, syzbot
> > <[email protected]> wrote:
> >> Hello,
> >>
> >> syzbot found the following issue on:
> >>
> >> HEAD commit: 950b879b7f02 riscv: Fixup race condition on PG_dcache_clea..
> >> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> >> console output: https://syzkaller.appspot.com/x/log.txt?x=10c4c1f7c80000
> >> kernel config: https://syzkaller.appspot.com/x/.config?x=ecebece1b90c0342
> >> dashboard link: https://syzkaller.appspot.com/bug?extid=01e9a564dc6b3289cea3
> >> compiler: riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> >> userspace arch: riscv64
> >>
> >> Unfortunately, I don't have any reproducer for this issue yet.
> >>
> >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> >> Reported-by: [email protected]
> >>
> >> ==================================================================
> >> BUG: KASAN: stack-out-of-bounds in walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> >> Read of size 8 at addr ff200000030a79b0 by task syz-executor.1/7894
> >>
> >> CPU: 0 PID: 7894 Comm: syz-executor.1 Tainted: G W 6.2.0-rc1-syzkaller #0
> >> Hardware name: riscv-virtio,qemu (DT)
> >> Call Trace:
> >> [<ffffffff8000b9ea>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121
> >> [<ffffffff83402b96>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127
> >> [<ffffffff83442726>] __dump_stack lib/dump_stack.c:88 [inline]
> >> [<ffffffff83442726>] dump_stack_lvl+0xe0/0x14c lib/dump_stack.c:106
> >> [<ffffffff83409674>] print_address_description mm/kasan/report.c:306 [inline]
> >> [<ffffffff83409674>] print_report+0x1e4/0x4c0 mm/kasan/report.c:417
> >> [<ffffffff804ead14>] kasan_report+0xb8/0xe6 mm/kasan/report.c:517
> >> [<ffffffff804ebea4>] check_region_inline mm/kasan/generic.c:183 [inline]
> >> [<ffffffff804ebea4>] __asan_load8+0x7e/0xa6 mm/kasan/generic.c:256
> >> [<ffffffff8000b782>] walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> > +riscv maintainers
> >
> > I think this is an issue in riscv stack walking.
> > If it's imprecise or walks stacks of running tasks, it needs to use
> > READ_ONCE_NOCHECK.
> >
> > #syz set subsystems: riscv
>
>
> This fix was merged in 6.3: commit 76950340cf03 ("riscv: Use
> READ_ONCE_NOCHECK in imprecise unwinding stack mode").
Oh, I see, syzbot riscv build is still broken due to:
https://syzkaller.appspot.com/bug?id=502e4cca2c3c985c2125ffa945b8e636b7b100d7
https://lore.kernel.org/all/[email protected]/T/#md2075a04dd463fefe31f73e098672a69d948a1ce
so it still tests an older build.
#syz fix:
riscv: Use READ_ONCE_NOCHECK in imprecise unwinding stack mode
> >> [<ffffffff8000bc66>] arch_stack_walk+0x2c/0x3c arch/riscv/kernel/stacktrace.c:154
> >> [<ffffffff80190822>] stack_trace_save_tsk+0x14a/0x1bc kernel/stacktrace.c:150
> >> [<ffffffff80697822>] proc_pid_stack+0x146/0x1ee fs/proc/base.c:456
> >> [<ffffffff80698bb0>] proc_single_show+0x9c/0x148 fs/proc/base.c:777
> >> [<ffffffff805af580>] traverse.part.0+0x74/0x2ca fs/seq_file.c:111
> >> [<ffffffff805aff02>] traverse fs/seq_file.c:101 [inline]
> >> [<ffffffff805aff02>] seq_read_iter+0x72c/0x934 fs/seq_file.c:195
> >> [<ffffffff805b0224>] seq_read+0x11a/0x16e fs/seq_file.c:162
> >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:756 [inline]
> >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:743 [inline]
> >> [<ffffffff805453ea>] do_iter_read+0x324/0x3c2 fs/read_write.c:798
> >> [<ffffffff805455f8>] vfs_readv+0xfe/0x166 fs/read_write.c:916
> >> [<ffffffff80549c66>] do_preadv fs/read_write.c:1008 [inline]
> >> [<ffffffff80549c66>] __do_sys_preadv fs/read_write.c:1058 [inline]
> >> [<ffffffff80549c66>] sys_preadv+0x182/0x1fa fs/read_write.c:1053
> >> [<ffffffff80005ff6>] ret_from_syscall+0x0/0x2
> >>
> >> The buggy address belongs to the virtual mapping at
> >> [ff200000030a0000, ff200000030a9000) created by:
> >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> >>
> >> The buggy address belongs to the physical page:
> >> page:ff1c0000024e5f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9397c
> >> memcg:ff6000000ffd7202
> >> flags: 0xffe000000000000(node=0|zone=0|lastcpupid=0x7ff)
> >> raw: 0ffe000000000000 0000000000000000 0000000000000122 0000000000000000
> >> raw: 0000000000000000 0000000000000000 00000001ffffffff ff6000000ffd7202
> >> page dumped because: kasan: bad access detected
> >> page_owner tracks the page as allocated
> >> page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 7873, tgid 7873 (syz-executor.1), ts 4012100669800, free_ts 4010400733200
> >> __set_page_owner+0x32/0x182 mm/page_owner.c:190
> >> set_page_owner include/linux/page_owner.h:31 [inline]
> >> post_alloc_hook+0xf8/0x11a mm/page_alloc.c:2524
> >> prep_new_page mm/page_alloc.c:2531 [inline]
> >> get_page_from_freelist+0xc0e/0x1118 mm/page_alloc.c:4283
> >> __alloc_pages+0x1b0/0x165a mm/page_alloc.c:5549
> >> alloc_pages+0x132/0x25e mm/mempolicy.c:2286
> >> vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
> >> __vmalloc_area_node mm/vmalloc.c:3057 [inline]
> >> __vmalloc_node_range+0x81c/0xdb4 mm/vmalloc.c:3227
> >> alloc_thread_stack_node kernel/fork.c:311 [inline]
> >> dup_task_struct kernel/fork.c:987 [inline]
> >> copy_process+0x210e/0x4068 kernel/fork.c:2097
> >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> >> __do_sys_clone+0xec/0x120 kernel/fork.c:2822
> >> sys_clone+0x32/0x44 kernel/fork.c:2790
> >> ret_from_syscall+0x0/0x2
> >> page last free stack trace:
> >> __reset_page_owner+0x4a/0xf8 mm/page_owner.c:148
> >> reset_page_owner include/linux/page_owner.h:24 [inline]
> >> free_pages_prepare mm/page_alloc.c:1446 [inline]
> >> free_pcp_prepare+0x254/0x48e mm/page_alloc.c:1496
> >> free_unref_page_prepare mm/page_alloc.c:3369 [inline]
> >> free_unref_page_list+0x11e/0x736 mm/page_alloc.c:3510
> >> release_pages+0x85a/0xbb2 mm/swap.c:1076
> >> free_pages_and_swap_cache+0x76/0x88 mm/swap_state.c:311
> >> tlb_batch_pages_flush+0x86/0x10c mm/mmu_gather.c:97
> >> tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
> >> tlb_flush_mmu mm/mmu_gather.c:299 [inline]
> >> tlb_finish_mmu+0xcc/0x280 mm/mmu_gather.c:391
> >> exit_mmap+0x190/0x686 mm/mmap.c:3096
> >> __mmput+0x98/0x290 kernel/fork.c:1207
> >> mmput+0x74/0x88 kernel/fork.c:1229
> >> exit_mm kernel/exit.c:563 [inline]
> >> do_exit+0x602/0x17be kernel/exit.c:854
> >> do_group_exit+0x8e/0x15e kernel/exit.c:1012
> >> __do_sys_exit_group kernel/exit.c:1023 [inline]
> >> __wake_up_parent+0x0/0x4a kernel/exit.c:1021
> >> ret_from_syscall+0x0/0x2
> >>
> >> Memory state around the buggy address:
> >> ff200000030a7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >> ff200000030a7900: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2
> >>> ff200000030a7980: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
> >> ^
> >> ff200000030a7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >> ff200000030a7a80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
> >> ==================================================================
> >>
> >>
> >> ---
> >> This report is generated by a bot. It may contain errors.
> >> See https://goo.gl/tpsmEJ for more information about syzbot.
> >> syzbot engineers can be reached at [email protected].
> >>
> >> syzbot will keep track of this issue. See:
> >> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >>
> >> If the bug is already fixed, let syzbot know by replying with:
> >> #syz fix: exact-commit-title
> >>
> >> If you want to change bug's subsystems, reply with:
> >> #syz set subsystems: new-subsystem
> >> (See the list of subsystem names on the web dashboard)
> >>
> >> If the bug is a duplicate of another bug, reply with:
> >> #syz dup: exact-subject-of-another-report
> >>
> >> If you want to undo deduplication, reply with:
> >> #syz undup
> >>
> >> --
> >> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> >> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> >> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/00000000000084706805fab08e27%40google.com.
> > _______________________________________________
> > linux-riscv mailing list
> > [email protected]
> > http://lists.infradead.org/mailman/listinfo/linux-riscv
On Tue, May 02, 2023 at 02:32:33PM +0200, Dmitry Vyukov wrote:
> On Tue, 2 May 2023 at 14:02, Alexandre Ghiti <[email protected]> wrote:
> >
> > On 5/2/23 09:15, Dmitry Vyukov wrote:
> > > On Tue, 2 May 2023 at 09:05, syzbot
> > > <[email protected]> wrote:
> > >> Hello,
> > >>
> > >> syzbot found the following issue on:
> > >>
> > >> HEAD commit: 950b879b7f02 riscv: Fixup race condition on PG_dcache_clea..
> > >> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> > >> console output: https://syzkaller.appspot.com/x/log.txt?x=10c4c1f7c80000
> > >> kernel config: https://syzkaller.appspot.com/x/.config?x=ecebece1b90c0342
> > >> dashboard link: https://syzkaller.appspot.com/bug?extid=01e9a564dc6b3289cea3
> > >> compiler: riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> > >> userspace arch: riscv64
> > >>
> > >> Unfortunately, I don't have any reproducer for this issue yet.
> > >>
> > >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > >> Reported-by: [email protected]
> > >>
> > >> ==================================================================
> > >> BUG: KASAN: stack-out-of-bounds in walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> > >> Read of size 8 at addr ff200000030a79b0 by task syz-executor.1/7894
> > >>
> > >> CPU: 0 PID: 7894 Comm: syz-executor.1 Tainted: G W 6.2.0-rc1-syzkaller #0
> > >> Hardware name: riscv-virtio,qemu (DT)
> > >> Call Trace:
> > >> [<ffffffff8000b9ea>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121
> > >> [<ffffffff83402b96>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127
> > >> [<ffffffff83442726>] __dump_stack lib/dump_stack.c:88 [inline]
> > >> [<ffffffff83442726>] dump_stack_lvl+0xe0/0x14c lib/dump_stack.c:106
> > >> [<ffffffff83409674>] print_address_description mm/kasan/report.c:306 [inline]
> > >> [<ffffffff83409674>] print_report+0x1e4/0x4c0 mm/kasan/report.c:417
> > >> [<ffffffff804ead14>] kasan_report+0xb8/0xe6 mm/kasan/report.c:517
> > >> [<ffffffff804ebea4>] check_region_inline mm/kasan/generic.c:183 [inline]
> > >> [<ffffffff804ebea4>] __asan_load8+0x7e/0xa6 mm/kasan/generic.c:256
> > >> [<ffffffff8000b782>] walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> > > +riscv maintainers
> > >
> > > I think this is an issue in riscv stack walking.
> > > If it's imprecise or walks stacks of running tasks, it needs to use
> > > READ_ONCE_NOCHECK.
> > >
> > > #syz set subsystems: riscv
> >
> >
> > This fix was merged in 6.3: commit 76950340cf03 ("riscv: Use
> > READ_ONCE_NOCHECK in imprecise unwinding stack mode").
>
> Oh, I see, syzbot riscv build is still broken due to:
> https://syzkaller.appspot.com/bug?id=502e4cca2c3c985c2125ffa945b8e636b7b100d7
I think this one is correct, but
> https://lore.kernel.org/all/[email protected]/T/#md2075a04dd463fefe31f73e098672a69d948a1ce
this isn't the right lore link. I think you meant:
https://lore.kernel.org/linux-riscv/CANp29Y5dbsSjd5q2TNJYgO5U1d6wu+XSSWR3PHWTX_efg7VyEA@mail.gmail.com/
The fix for that went through the bpf tree though:
https://lore.kernel.org/bpf/[email protected]/T/
Perhaps that is now fixed in mainline? I think riscv/fixes just needs to
be updated (it normally is after -rc1 I think) and things should be
good to go, no?
Cheers,
Conor.
>
> so it still tests an older build.
>
> #syz fix:
> riscv: Use READ_ONCE_NOCHECK in imprecise unwinding stack mode
>
> > >> [<ffffffff8000bc66>] arch_stack_walk+0x2c/0x3c arch/riscv/kernel/stacktrace.c:154
> > >> [<ffffffff80190822>] stack_trace_save_tsk+0x14a/0x1bc kernel/stacktrace.c:150
> > >> [<ffffffff80697822>] proc_pid_stack+0x146/0x1ee fs/proc/base.c:456
> > >> [<ffffffff80698bb0>] proc_single_show+0x9c/0x148 fs/proc/base.c:777
> > >> [<ffffffff805af580>] traverse.part.0+0x74/0x2ca fs/seq_file.c:111
> > >> [<ffffffff805aff02>] traverse fs/seq_file.c:101 [inline]
> > >> [<ffffffff805aff02>] seq_read_iter+0x72c/0x934 fs/seq_file.c:195
> > >> [<ffffffff805b0224>] seq_read+0x11a/0x16e fs/seq_file.c:162
> > >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:756 [inline]
> > >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:743 [inline]
> > >> [<ffffffff805453ea>] do_iter_read+0x324/0x3c2 fs/read_write.c:798
> > >> [<ffffffff805455f8>] vfs_readv+0xfe/0x166 fs/read_write.c:916
> > >> [<ffffffff80549c66>] do_preadv fs/read_write.c:1008 [inline]
> > >> [<ffffffff80549c66>] __do_sys_preadv fs/read_write.c:1058 [inline]
> > >> [<ffffffff80549c66>] sys_preadv+0x182/0x1fa fs/read_write.c:1053
> > >> [<ffffffff80005ff6>] ret_from_syscall+0x0/0x2
> > >>
> > >> The buggy address belongs to the virtual mapping at
> > >> [ff200000030a0000, ff200000030a9000) created by:
> > >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> > >>
> > >> The buggy address belongs to the physical page:
> > >> page:ff1c0000024e5f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9397c
> > >> memcg:ff6000000ffd7202
> > >> flags: 0xffe000000000000(node=0|zone=0|lastcpupid=0x7ff)
> > >> raw: 0ffe000000000000 0000000000000000 0000000000000122 0000000000000000
> > >> raw: 0000000000000000 0000000000000000 00000001ffffffff ff6000000ffd7202
> > >> page dumped because: kasan: bad access detected
> > >> page_owner tracks the page as allocated
> > >> page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 7873, tgid 7873 (syz-executor.1), ts 4012100669800, free_ts 4010400733200
> > >> __set_page_owner+0x32/0x182 mm/page_owner.c:190
> > >> set_page_owner include/linux/page_owner.h:31 [inline]
> > >> post_alloc_hook+0xf8/0x11a mm/page_alloc.c:2524
> > >> prep_new_page mm/page_alloc.c:2531 [inline]
> > >> get_page_from_freelist+0xc0e/0x1118 mm/page_alloc.c:4283
> > >> __alloc_pages+0x1b0/0x165a mm/page_alloc.c:5549
> > >> alloc_pages+0x132/0x25e mm/mempolicy.c:2286
> > >> vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
> > >> __vmalloc_area_node mm/vmalloc.c:3057 [inline]
> > >> __vmalloc_node_range+0x81c/0xdb4 mm/vmalloc.c:3227
> > >> alloc_thread_stack_node kernel/fork.c:311 [inline]
> > >> dup_task_struct kernel/fork.c:987 [inline]
> > >> copy_process+0x210e/0x4068 kernel/fork.c:2097
> > >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> > >> __do_sys_clone+0xec/0x120 kernel/fork.c:2822
> > >> sys_clone+0x32/0x44 kernel/fork.c:2790
> > >> ret_from_syscall+0x0/0x2
> > >> page last free stack trace:
> > >> __reset_page_owner+0x4a/0xf8 mm/page_owner.c:148
> > >> reset_page_owner include/linux/page_owner.h:24 [inline]
> > >> free_pages_prepare mm/page_alloc.c:1446 [inline]
> > >> free_pcp_prepare+0x254/0x48e mm/page_alloc.c:1496
> > >> free_unref_page_prepare mm/page_alloc.c:3369 [inline]
> > >> free_unref_page_list+0x11e/0x736 mm/page_alloc.c:3510
> > >> release_pages+0x85a/0xbb2 mm/swap.c:1076
> > >> free_pages_and_swap_cache+0x76/0x88 mm/swap_state.c:311
> > >> tlb_batch_pages_flush+0x86/0x10c mm/mmu_gather.c:97
> > >> tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
> > >> tlb_flush_mmu mm/mmu_gather.c:299 [inline]
> > >> tlb_finish_mmu+0xcc/0x280 mm/mmu_gather.c:391
> > >> exit_mmap+0x190/0x686 mm/mmap.c:3096
> > >> __mmput+0x98/0x290 kernel/fork.c:1207
> > >> mmput+0x74/0x88 kernel/fork.c:1229
> > >> exit_mm kernel/exit.c:563 [inline]
> > >> do_exit+0x602/0x17be kernel/exit.c:854
> > >> do_group_exit+0x8e/0x15e kernel/exit.c:1012
> > >> __do_sys_exit_group kernel/exit.c:1023 [inline]
> > >> __wake_up_parent+0x0/0x4a kernel/exit.c:1021
> > >> ret_from_syscall+0x0/0x2
> > >>
> > >> Memory state around the buggy address:
> > >> ff200000030a7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > >> ff200000030a7900: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2
> > >>> ff200000030a7980: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
> > >> ^
> > >> ff200000030a7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > >> ff200000030a7a80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
> > >> ==================================================================
> > >>
> > >>
> > >> ---
> > >> This report is generated by a bot. It may contain errors.
> > >> See https://goo.gl/tpsmEJ for more information about syzbot.
> > >> syzbot engineers can be reached at [email protected].
> > >>
> > >> syzbot will keep track of this issue. See:
> > >> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> > >>
> > >> If the bug is already fixed, let syzbot know by replying with:
> > >> #syz fix: exact-commit-title
> > >>
> > >> If you want to change bug's subsystems, reply with:
> > >> #syz set subsystems: new-subsystem
> > >> (See the list of subsystem names on the web dashboard)
> > >>
> > >> If the bug is a duplicate of another bug, reply with:
> > >> #syz dup: exact-subject-of-another-report
> > >>
> > >> If you want to undo deduplication, reply with:
> > >> #syz undup
> > >>
> > >> --
> > >> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> > >> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> > >> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/00000000000084706805fab08e27%40google.com.
> > > _______________________________________________
> > > linux-riscv mailing list
> > > [email protected]
> > > http://lists.infradead.org/mailman/listinfo/linux-riscv
On Tue, May 2, 2023 at 2:32 PM Dmitry Vyukov <[email protected]> wrote:
>
> On Tue, 2 May 2023 at 14:02, Alexandre Ghiti <[email protected]> wrote:
> >
> > On 5/2/23 09:15, Dmitry Vyukov wrote:
> > > On Tue, 2 May 2023 at 09:05, syzbot
> > > <[email protected]> wrote:
> > >> Hello,
> > >>
> > >> syzbot found the following issue on:
> > >>
> > >> HEAD commit: 950b879b7f02 riscv: Fixup race condition on PG_dcache_clea..
> > >> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> > >> console output: https://syzkaller.appspot.com/x/log.txt?x=10c4c1f7c80000
> > >> kernel config: https://syzkaller.appspot.com/x/.config?x=ecebece1b90c0342
> > >> dashboard link: https://syzkaller.appspot.com/bug?extid=01e9a564dc6b3289cea3
> > >> compiler: riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> > >> userspace arch: riscv64
> > >>
> > >> Unfortunately, I don't have any reproducer for this issue yet.
> > >>
> > >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > >> Reported-by: [email protected]
> > >>
> > >> ==================================================================
> > >> BUG: KASAN: stack-out-of-bounds in walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> > >> Read of size 8 at addr ff200000030a79b0 by task syz-executor.1/7894
> > >>
> > >> CPU: 0 PID: 7894 Comm: syz-executor.1 Tainted: G W 6.2.0-rc1-syzkaller #0
> > >> Hardware name: riscv-virtio,qemu (DT)
> > >> Call Trace:
> > >> [<ffffffff8000b9ea>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121
> > >> [<ffffffff83402b96>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127
> > >> [<ffffffff83442726>] __dump_stack lib/dump_stack.c:88 [inline]
> > >> [<ffffffff83442726>] dump_stack_lvl+0xe0/0x14c lib/dump_stack.c:106
> > >> [<ffffffff83409674>] print_address_description mm/kasan/report.c:306 [inline]
> > >> [<ffffffff83409674>] print_report+0x1e4/0x4c0 mm/kasan/report.c:417
> > >> [<ffffffff804ead14>] kasan_report+0xb8/0xe6 mm/kasan/report.c:517
> > >> [<ffffffff804ebea4>] check_region_inline mm/kasan/generic.c:183 [inline]
> > >> [<ffffffff804ebea4>] __asan_load8+0x7e/0xa6 mm/kasan/generic.c:256
> > >> [<ffffffff8000b782>] walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> > > +riscv maintainers
> > >
> > > I think this is an issue in riscv stack walking.
> > > If it's imprecise or walks stacks of running tasks, it needs to use
> > > READ_ONCE_NOCHECK.
> > >
> > > #syz set subsystems: riscv
> >
> >
> > This fix was merged in 6.3: commit 76950340cf03 ("riscv: Use
> > READ_ONCE_NOCHECK in imprecise unwinding stack mode").
>
> Oh, I see, syzbot riscv build is still broken due to:
> https://syzkaller.appspot.com/bug?id=502e4cca2c3c985c2125ffa945b8e636b7b100d7
The fix for that was merged in 6.3-rc2 too (commit 2d311f480b52
("riscv, bpf: Fix patch_text implicit declaration")): but the fixes
branch is still based on top of Linux 6.3-rc1 (Aleksandr mentioned
that already).
> https://lore.kernel.org/all/[email protected]/T/#md2075a04dd463fefe31f73e098672a69d948a1ce
That's weird, I think this one was merged in v6.1-rc2 (commit
5c20a3a9df19 ("RISC-V: Fix compilation without RISCV_ISA_ZICBOM")).
>
> so it still tests an older build.
FYI, the latest fixes for KASAN were merged in 6.4 (or are about to).
Thanks,
Alex
>
> #syz fix:
> riscv: Use READ_ONCE_NOCHECK in imprecise unwinding stack mode
>
> > >> [<ffffffff8000bc66>] arch_stack_walk+0x2c/0x3c arch/riscv/kernel/stacktrace.c:154
> > >> [<ffffffff80190822>] stack_trace_save_tsk+0x14a/0x1bc kernel/stacktrace.c:150
> > >> [<ffffffff80697822>] proc_pid_stack+0x146/0x1ee fs/proc/base.c:456
> > >> [<ffffffff80698bb0>] proc_single_show+0x9c/0x148 fs/proc/base.c:777
> > >> [<ffffffff805af580>] traverse.part.0+0x74/0x2ca fs/seq_file.c:111
> > >> [<ffffffff805aff02>] traverse fs/seq_file.c:101 [inline]
> > >> [<ffffffff805aff02>] seq_read_iter+0x72c/0x934 fs/seq_file.c:195
> > >> [<ffffffff805b0224>] seq_read+0x11a/0x16e fs/seq_file.c:162
> > >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:756 [inline]
> > >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:743 [inline]
> > >> [<ffffffff805453ea>] do_iter_read+0x324/0x3c2 fs/read_write.c:798
> > >> [<ffffffff805455f8>] vfs_readv+0xfe/0x166 fs/read_write.c:916
> > >> [<ffffffff80549c66>] do_preadv fs/read_write.c:1008 [inline]
> > >> [<ffffffff80549c66>] __do_sys_preadv fs/read_write.c:1058 [inline]
> > >> [<ffffffff80549c66>] sys_preadv+0x182/0x1fa fs/read_write.c:1053
> > >> [<ffffffff80005ff6>] ret_from_syscall+0x0/0x2
> > >>
> > >> The buggy address belongs to the virtual mapping at
> > >> [ff200000030a0000, ff200000030a9000) created by:
> > >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> > >>
> > >> The buggy address belongs to the physical page:
> > >> page:ff1c0000024e5f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9397c
> > >> memcg:ff6000000ffd7202
> > >> flags: 0xffe000000000000(node=0|zone=0|lastcpupid=0x7ff)
> > >> raw: 0ffe000000000000 0000000000000000 0000000000000122 0000000000000000
> > >> raw: 0000000000000000 0000000000000000 00000001ffffffff ff6000000ffd7202
> > >> page dumped because: kasan: bad access detected
> > >> page_owner tracks the page as allocated
> > >> page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 7873, tgid 7873 (syz-executor.1), ts 4012100669800, free_ts 4010400733200
> > >> __set_page_owner+0x32/0x182 mm/page_owner.c:190
> > >> set_page_owner include/linux/page_owner.h:31 [inline]
> > >> post_alloc_hook+0xf8/0x11a mm/page_alloc.c:2524
> > >> prep_new_page mm/page_alloc.c:2531 [inline]
> > >> get_page_from_freelist+0xc0e/0x1118 mm/page_alloc.c:4283
> > >> __alloc_pages+0x1b0/0x165a mm/page_alloc.c:5549
> > >> alloc_pages+0x132/0x25e mm/mempolicy.c:2286
> > >> vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
> > >> __vmalloc_area_node mm/vmalloc.c:3057 [inline]
> > >> __vmalloc_node_range+0x81c/0xdb4 mm/vmalloc.c:3227
> > >> alloc_thread_stack_node kernel/fork.c:311 [inline]
> > >> dup_task_struct kernel/fork.c:987 [inline]
> > >> copy_process+0x210e/0x4068 kernel/fork.c:2097
> > >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> > >> __do_sys_clone+0xec/0x120 kernel/fork.c:2822
> > >> sys_clone+0x32/0x44 kernel/fork.c:2790
> > >> ret_from_syscall+0x0/0x2
> > >> page last free stack trace:
> > >> __reset_page_owner+0x4a/0xf8 mm/page_owner.c:148
> > >> reset_page_owner include/linux/page_owner.h:24 [inline]
> > >> free_pages_prepare mm/page_alloc.c:1446 [inline]
> > >> free_pcp_prepare+0x254/0x48e mm/page_alloc.c:1496
> > >> free_unref_page_prepare mm/page_alloc.c:3369 [inline]
> > >> free_unref_page_list+0x11e/0x736 mm/page_alloc.c:3510
> > >> release_pages+0x85a/0xbb2 mm/swap.c:1076
> > >> free_pages_and_swap_cache+0x76/0x88 mm/swap_state.c:311
> > >> tlb_batch_pages_flush+0x86/0x10c mm/mmu_gather.c:97
> > >> tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
> > >> tlb_flush_mmu mm/mmu_gather.c:299 [inline]
> > >> tlb_finish_mmu+0xcc/0x280 mm/mmu_gather.c:391
> > >> exit_mmap+0x190/0x686 mm/mmap.c:3096
> > >> __mmput+0x98/0x290 kernel/fork.c:1207
> > >> mmput+0x74/0x88 kernel/fork.c:1229
> > >> exit_mm kernel/exit.c:563 [inline]
> > >> do_exit+0x602/0x17be kernel/exit.c:854
> > >> do_group_exit+0x8e/0x15e kernel/exit.c:1012
> > >> __do_sys_exit_group kernel/exit.c:1023 [inline]
> > >> __wake_up_parent+0x0/0x4a kernel/exit.c:1021
> > >> ret_from_syscall+0x0/0x2
> > >>
> > >> Memory state around the buggy address:
> > >> ff200000030a7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > >> ff200000030a7900: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2
> > >>> ff200000030a7980: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
> > >> ^
> > >> ff200000030a7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > >> ff200000030a7a80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
> > >> ==================================================================
> > >>
> > >>
> > >> ---
> > >> This report is generated by a bot. It may contain errors.
> > >> See https://goo.gl/tpsmEJ for more information about syzbot.
> > >> syzbot engineers can be reached at [email protected].
> > >>
> > >> syzbot will keep track of this issue. See:
> > >> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> > >>
> > >> If the bug is already fixed, let syzbot know by replying with:
> > >> #syz fix: exact-commit-title
> > >>
> > >> If you want to change bug's subsystems, reply with:
> > >> #syz set subsystems: new-subsystem
> > >> (See the list of subsystem names on the web dashboard)
> > >>
> > >> If the bug is a duplicate of another bug, reply with:
> > >> #syz dup: exact-subject-of-another-report
> > >>
> > >> If you want to undo deduplication, reply with:
> > >> #syz undup
> > >>
> > >> --
> > >> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> > >> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> > >> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/00000000000084706805fab08e27%40google.com.
> > > _______________________________________________
> > > linux-riscv mailing list
> > > [email protected]
> > > http://lists.infradead.org/mailman/listinfo/linux-riscv
On Tue, 2 May 2023 at 14:46, Alexandre Ghiti <[email protected]> wrote:
> > > On 5/2/23 09:15, Dmitry Vyukov wrote:
> > > > On Tue, 2 May 2023 at 09:05, syzbot
> > > > <[email protected]> wrote:
> > > >> Hello,
> > > >>
> > > >> syzbot found the following issue on:
> > > >>
> > > >> HEAD commit: 950b879b7f02 riscv: Fixup race condition on PG_dcache_clea..
> > > >> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> > > >> console output: https://syzkaller.appspot.com/x/log.txt?x=10c4c1f7c80000
> > > >> kernel config: https://syzkaller.appspot.com/x/.config?x=ecebece1b90c0342
> > > >> dashboard link: https://syzkaller.appspot.com/bug?extid=01e9a564dc6b3289cea3
> > > >> compiler: riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> > > >> userspace arch: riscv64
> > > >>
> > > >> Unfortunately, I don't have any reproducer for this issue yet.
> > > >>
> > > >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > >> Reported-by: [email protected]
> > > >>
> > > >> ==================================================================
> > > >> BUG: KASAN: stack-out-of-bounds in walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> > > >> Read of size 8 at addr ff200000030a79b0 by task syz-executor.1/7894
> > > >>
> > > >> CPU: 0 PID: 7894 Comm: syz-executor.1 Tainted: G W 6.2.0-rc1-syzkaller #0
> > > >> Hardware name: riscv-virtio,qemu (DT)
> > > >> Call Trace:
> > > >> [<ffffffff8000b9ea>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121
> > > >> [<ffffffff83402b96>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127
> > > >> [<ffffffff83442726>] __dump_stack lib/dump_stack.c:88 [inline]
> > > >> [<ffffffff83442726>] dump_stack_lvl+0xe0/0x14c lib/dump_stack.c:106
> > > >> [<ffffffff83409674>] print_address_description mm/kasan/report.c:306 [inline]
> > > >> [<ffffffff83409674>] print_report+0x1e4/0x4c0 mm/kasan/report.c:417
> > > >> [<ffffffff804ead14>] kasan_report+0xb8/0xe6 mm/kasan/report.c:517
> > > >> [<ffffffff804ebea4>] check_region_inline mm/kasan/generic.c:183 [inline]
> > > >> [<ffffffff804ebea4>] __asan_load8+0x7e/0xa6 mm/kasan/generic.c:256
> > > >> [<ffffffff8000b782>] walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> > > > +riscv maintainers
> > > >
> > > > I think this is an issue in riscv stack walking.
> > > > If it's imprecise or walks stacks of running tasks, it needs to use
> > > > READ_ONCE_NOCHECK.
> > > >
> > > > #syz set subsystems: riscv
> > >
> > >
> > > This fix was merged in 6.3: commit 76950340cf03 ("riscv: Use
> > > READ_ONCE_NOCHECK in imprecise unwinding stack mode").
> >
> > Oh, I see, syzbot riscv build is still broken due to:
> > https://syzkaller.appspot.com/bug?id=502e4cca2c3c985c2125ffa945b8e636b7b100d7
>
> The fix for that was merged in 6.3-rc2 too (commit 2d311f480b52
> ("riscv, bpf: Fix patch_text implicit declaration")): but the fixes
> branch is still based on top of Linux 6.3-rc1 (Aleksandr mentioned
> that already).
Is riscv-fixes the right branch to test?
Is there one that is updated regularly?
syzbot generally requires a fresh tree. Provided there are dozens of
bugs being found and fixed every week, if a tree becomes too old, it
just produces already fixed bugs that waste time.
https://lore.kernel.org/all/[email protected]/T/#md2075a04dd463fefe31f73e098672a69d948a1ce
>
> That's weird, I think this one was merged in v6.1-rc2 (commit
> 5c20a3a9df19 ("RISC-V: Fix compilation without RISCV_ISA_ZICBOM")).
>
> >
> > so it still tests an older build.
>
> FYI, the latest fixes for KASAN were merged in 6.4 (or are about to).
>
> Thanks,
>
> Alex
>
> >
> > #syz fix:
> > riscv: Use READ_ONCE_NOCHECK in imprecise unwinding stack mode
> >
> > > >> [<ffffffff8000bc66>] arch_stack_walk+0x2c/0x3c arch/riscv/kernel/stacktrace.c:154
> > > >> [<ffffffff80190822>] stack_trace_save_tsk+0x14a/0x1bc kernel/stacktrace.c:150
> > > >> [<ffffffff80697822>] proc_pid_stack+0x146/0x1ee fs/proc/base.c:456
> > > >> [<ffffffff80698bb0>] proc_single_show+0x9c/0x148 fs/proc/base.c:777
> > > >> [<ffffffff805af580>] traverse.part.0+0x74/0x2ca fs/seq_file.c:111
> > > >> [<ffffffff805aff02>] traverse fs/seq_file.c:101 [inline]
> > > >> [<ffffffff805aff02>] seq_read_iter+0x72c/0x934 fs/seq_file.c:195
> > > >> [<ffffffff805b0224>] seq_read+0x11a/0x16e fs/seq_file.c:162
> > > >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:756 [inline]
> > > >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:743 [inline]
> > > >> [<ffffffff805453ea>] do_iter_read+0x324/0x3c2 fs/read_write.c:798
> > > >> [<ffffffff805455f8>] vfs_readv+0xfe/0x166 fs/read_write.c:916
> > > >> [<ffffffff80549c66>] do_preadv fs/read_write.c:1008 [inline]
> > > >> [<ffffffff80549c66>] __do_sys_preadv fs/read_write.c:1058 [inline]
> > > >> [<ffffffff80549c66>] sys_preadv+0x182/0x1fa fs/read_write.c:1053
> > > >> [<ffffffff80005ff6>] ret_from_syscall+0x0/0x2
> > > >>
> > > >> The buggy address belongs to the virtual mapping at
> > > >> [ff200000030a0000, ff200000030a9000) created by:
> > > >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> > > >>
> > > >> The buggy address belongs to the physical page:
> > > >> page:ff1c0000024e5f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9397c
> > > >> memcg:ff6000000ffd7202
> > > >> flags: 0xffe000000000000(node=0|zone=0|lastcpupid=0x7ff)
> > > >> raw: 0ffe000000000000 0000000000000000 0000000000000122 0000000000000000
> > > >> raw: 0000000000000000 0000000000000000 00000001ffffffff ff6000000ffd7202
> > > >> page dumped because: kasan: bad access detected
> > > >> page_owner tracks the page as allocated
> > > >> page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 7873, tgid 7873 (syz-executor.1), ts 4012100669800, free_ts 4010400733200
> > > >> __set_page_owner+0x32/0x182 mm/page_owner.c:190
> > > >> set_page_owner include/linux/page_owner.h:31 [inline]
> > > >> post_alloc_hook+0xf8/0x11a mm/page_alloc.c:2524
> > > >> prep_new_page mm/page_alloc.c:2531 [inline]
> > > >> get_page_from_freelist+0xc0e/0x1118 mm/page_alloc.c:4283
> > > >> __alloc_pages+0x1b0/0x165a mm/page_alloc.c:5549
> > > >> alloc_pages+0x132/0x25e mm/mempolicy.c:2286
> > > >> vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
> > > >> __vmalloc_area_node mm/vmalloc.c:3057 [inline]
> > > >> __vmalloc_node_range+0x81c/0xdb4 mm/vmalloc.c:3227
> > > >> alloc_thread_stack_node kernel/fork.c:311 [inline]
> > > >> dup_task_struct kernel/fork.c:987 [inline]
> > > >> copy_process+0x210e/0x4068 kernel/fork.c:2097
> > > >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> > > >> __do_sys_clone+0xec/0x120 kernel/fork.c:2822
> > > >> sys_clone+0x32/0x44 kernel/fork.c:2790
> > > >> ret_from_syscall+0x0/0x2
> > > >> page last free stack trace:
> > > >> __reset_page_owner+0x4a/0xf8 mm/page_owner.c:148
> > > >> reset_page_owner include/linux/page_owner.h:24 [inline]
> > > >> free_pages_prepare mm/page_alloc.c:1446 [inline]
> > > >> free_pcp_prepare+0x254/0x48e mm/page_alloc.c:1496
> > > >> free_unref_page_prepare mm/page_alloc.c:3369 [inline]
> > > >> free_unref_page_list+0x11e/0x736 mm/page_alloc.c:3510
> > > >> release_pages+0x85a/0xbb2 mm/swap.c:1076
> > > >> free_pages_and_swap_cache+0x76/0x88 mm/swap_state.c:311
> > > >> tlb_batch_pages_flush+0x86/0x10c mm/mmu_gather.c:97
> > > >> tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
> > > >> tlb_flush_mmu mm/mmu_gather.c:299 [inline]
> > > >> tlb_finish_mmu+0xcc/0x280 mm/mmu_gather.c:391
> > > >> exit_mmap+0x190/0x686 mm/mmap.c:3096
> > > >> __mmput+0x98/0x290 kernel/fork.c:1207
> > > >> mmput+0x74/0x88 kernel/fork.c:1229
> > > >> exit_mm kernel/exit.c:563 [inline]
> > > >> do_exit+0x602/0x17be kernel/exit.c:854
> > > >> do_group_exit+0x8e/0x15e kernel/exit.c:1012
> > > >> __do_sys_exit_group kernel/exit.c:1023 [inline]
> > > >> __wake_up_parent+0x0/0x4a kernel/exit.c:1021
> > > >> ret_from_syscall+0x0/0x2
> > > >>
> > > >> Memory state around the buggy address:
> > > >> ff200000030a7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > > >> ff200000030a7900: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2
> > > >>> ff200000030a7980: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
> > > >> ^
> > > >> ff200000030a7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > > >> ff200000030a7a80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
> > > >> ==================================================================
> > > >>
> > > >>
> > > >> ---
> > > >> This report is generated by a bot. It may contain errors.
> > > >> See https://goo.gl/tpsmEJ for more information about syzbot.
> > > >> syzbot engineers can be reached at [email protected].
> > > >>
> > > >> syzbot will keep track of this issue. See:
> > > >> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> > > >>
> > > >> If the bug is already fixed, let syzbot know by replying with:
> > > >> #syz fix: exact-commit-title
> > > >>
> > > >> If you want to change bug's subsystems, reply with:
> > > >> #syz set subsystems: new-subsystem
> > > >> (See the list of subsystem names on the web dashboard)
> > > >>
> > > >> If the bug is a duplicate of another bug, reply with:
> > > >> #syz dup: exact-subject-of-another-report
> > > >>
> > > >> If you want to undo deduplication, reply with:
> > > >> #syz undup
> > > >>
> > > >> --
> > > >> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> > > >> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> > > >> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/00000000000084706805fab08e27%40google.com.
> > > > _______________________________________________
> > > > linux-riscv mailing list
> > > > [email protected]
> > > > http://lists.infradead.org/mailman/listinfo/linux-riscv
On Tue, May 2, 2023 at 2:50 PM Dmitry Vyukov <[email protected]> wrote:
>
> On Tue, 2 May 2023 at 14:46, Alexandre Ghiti <[email protected]> wrote:
> > > > On 5/2/23 09:15, Dmitry Vyukov wrote:
> > > > > On Tue, 2 May 2023 at 09:05, syzbot
> > > > > <[email protected]> wrote:
> > > > >> Hello,
> > > > >>
> > > > >> syzbot found the following issue on:
> > > > >>
> > > > >> HEAD commit: 950b879b7f02 riscv: Fixup race condition on PG_dcache_clea..
> > > > >> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> > > > >> console output: https://syzkaller.appspot.com/x/log.txt?x=10c4c1f7c80000
> > > > >> kernel config: https://syzkaller.appspot.com/x/.config?x=ecebece1b90c0342
> > > > >> dashboard link: https://syzkaller.appspot.com/bug?extid=01e9a564dc6b3289cea3
> > > > >> compiler: riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> > > > >> userspace arch: riscv64
> > > > >>
> > > > >> Unfortunately, I don't have any reproducer for this issue yet.
> > > > >>
> > > > >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > > >> Reported-by: [email protected]
> > > > >>
> > > > >> ==================================================================
> > > > >> BUG: KASAN: stack-out-of-bounds in walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> > > > >> Read of size 8 at addr ff200000030a79b0 by task syz-executor.1/7894
> > > > >>
> > > > >> CPU: 0 PID: 7894 Comm: syz-executor.1 Tainted: G W 6.2.0-rc1-syzkaller #0
> > > > >> Hardware name: riscv-virtio,qemu (DT)
> > > > >> Call Trace:
> > > > >> [<ffffffff8000b9ea>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:121
> > > > >> [<ffffffff83402b96>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:127
> > > > >> [<ffffffff83442726>] __dump_stack lib/dump_stack.c:88 [inline]
> > > > >> [<ffffffff83442726>] dump_stack_lvl+0xe0/0x14c lib/dump_stack.c:106
> > > > >> [<ffffffff83409674>] print_address_description mm/kasan/report.c:306 [inline]
> > > > >> [<ffffffff83409674>] print_report+0x1e4/0x4c0 mm/kasan/report.c:417
> > > > >> [<ffffffff804ead14>] kasan_report+0xb8/0xe6 mm/kasan/report.c:517
> > > > >> [<ffffffff804ebea4>] check_region_inline mm/kasan/generic.c:183 [inline]
> > > > >> [<ffffffff804ebea4>] __asan_load8+0x7e/0xa6 mm/kasan/generic.c:256
> > > > >> [<ffffffff8000b782>] walk_stackframe+0x128/0x2fe arch/riscv/kernel/stacktrace.c:58
> > > > > +riscv maintainers
> > > > >
> > > > > I think this is an issue in riscv stack walking.
> > > > > If it's imprecise or walks stacks of running tasks, it needs to use
> > > > > READ_ONCE_NOCHECK.
> > > > >
> > > > > #syz set subsystems: riscv
> > > >
> > > >
> > > > This fix was merged in 6.3: commit 76950340cf03 ("riscv: Use
> > > > READ_ONCE_NOCHECK in imprecise unwinding stack mode").
> > >
> > > Oh, I see, syzbot riscv build is still broken due to:
> > > https://syzkaller.appspot.com/bug?id=502e4cca2c3c985c2125ffa945b8e636b7b100d7
> >
> > The fix for that was merged in 6.3-rc2 too (commit 2d311f480b52
> > ("riscv, bpf: Fix patch_text implicit declaration")): but the fixes
> > branch is still based on top of Linux 6.3-rc1 (Aleksandr mentioned
> > that already).
>
> Is riscv-fixes the right branch to test?
> Is there one that is updated regularly?
> syzbot generally requires a fresh tree. Provided there are dozens of
> bugs being found and fixed every week, if a tree becomes too old, it
> just produces already fixed bugs that waste time.
I would say that testing only the latest rcX is the best bet for us as
the fixes branch always lags on rc1, but @Palmer/@Conor may have
another opinion.
>
> https://lore.kernel.org/all/[email protected]/T/#md2075a04dd463fefe31f73e098672a69d948a1ce
> >
> > That's weird, I think this one was merged in v6.1-rc2 (commit
> > 5c20a3a9df19 ("RISC-V: Fix compilation without RISCV_ISA_ZICBOM")).
> >
> > >
> > > so it still tests an older build.
> >
> > FYI, the latest fixes for KASAN were merged in 6.4 (or are about to).
> >
> > Thanks,
> >
> > Alex
> >
> > >
> > > #syz fix:
> > > riscv: Use READ_ONCE_NOCHECK in imprecise unwinding stack mode
> > >
> > > > >> [<ffffffff8000bc66>] arch_stack_walk+0x2c/0x3c arch/riscv/kernel/stacktrace.c:154
> > > > >> [<ffffffff80190822>] stack_trace_save_tsk+0x14a/0x1bc kernel/stacktrace.c:150
> > > > >> [<ffffffff80697822>] proc_pid_stack+0x146/0x1ee fs/proc/base.c:456
> > > > >> [<ffffffff80698bb0>] proc_single_show+0x9c/0x148 fs/proc/base.c:777
> > > > >> [<ffffffff805af580>] traverse.part.0+0x74/0x2ca fs/seq_file.c:111
> > > > >> [<ffffffff805aff02>] traverse fs/seq_file.c:101 [inline]
> > > > >> [<ffffffff805aff02>] seq_read_iter+0x72c/0x934 fs/seq_file.c:195
> > > > >> [<ffffffff805b0224>] seq_read+0x11a/0x16e fs/seq_file.c:162
> > > > >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:756 [inline]
> > > > >> [<ffffffff805453ea>] do_loop_readv_writev fs/read_write.c:743 [inline]
> > > > >> [<ffffffff805453ea>] do_iter_read+0x324/0x3c2 fs/read_write.c:798
> > > > >> [<ffffffff805455f8>] vfs_readv+0xfe/0x166 fs/read_write.c:916
> > > > >> [<ffffffff80549c66>] do_preadv fs/read_write.c:1008 [inline]
> > > > >> [<ffffffff80549c66>] __do_sys_preadv fs/read_write.c:1058 [inline]
> > > > >> [<ffffffff80549c66>] sys_preadv+0x182/0x1fa fs/read_write.c:1053
> > > > >> [<ffffffff80005ff6>] ret_from_syscall+0x0/0x2
> > > > >>
> > > > >> The buggy address belongs to the virtual mapping at
> > > > >> [ff200000030a0000, ff200000030a9000) created by:
> > > > >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> > > > >>
> > > > >> The buggy address belongs to the physical page:
> > > > >> page:ff1c0000024e5f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9397c
> > > > >> memcg:ff6000000ffd7202
> > > > >> flags: 0xffe000000000000(node=0|zone=0|lastcpupid=0x7ff)
> > > > >> raw: 0ffe000000000000 0000000000000000 0000000000000122 0000000000000000
> > > > >> raw: 0000000000000000 0000000000000000 00000001ffffffff ff6000000ffd7202
> > > > >> page dumped because: kasan: bad access detected
> > > > >> page_owner tracks the page as allocated
> > > > >> page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 7873, tgid 7873 (syz-executor.1), ts 4012100669800, free_ts 4010400733200
> > > > >> __set_page_owner+0x32/0x182 mm/page_owner.c:190
> > > > >> set_page_owner include/linux/page_owner.h:31 [inline]
> > > > >> post_alloc_hook+0xf8/0x11a mm/page_alloc.c:2524
> > > > >> prep_new_page mm/page_alloc.c:2531 [inline]
> > > > >> get_page_from_freelist+0xc0e/0x1118 mm/page_alloc.c:4283
> > > > >> __alloc_pages+0x1b0/0x165a mm/page_alloc.c:5549
> > > > >> alloc_pages+0x132/0x25e mm/mempolicy.c:2286
> > > > >> vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
> > > > >> __vmalloc_area_node mm/vmalloc.c:3057 [inline]
> > > > >> __vmalloc_node_range+0x81c/0xdb4 mm/vmalloc.c:3227
> > > > >> alloc_thread_stack_node kernel/fork.c:311 [inline]
> > > > >> dup_task_struct kernel/fork.c:987 [inline]
> > > > >> copy_process+0x210e/0x4068 kernel/fork.c:2097
> > > > >> kernel_clone+0xee/0x914 kernel/fork.c:2681
> > > > >> __do_sys_clone+0xec/0x120 kernel/fork.c:2822
> > > > >> sys_clone+0x32/0x44 kernel/fork.c:2790
> > > > >> ret_from_syscall+0x0/0x2
> > > > >> page last free stack trace:
> > > > >> __reset_page_owner+0x4a/0xf8 mm/page_owner.c:148
> > > > >> reset_page_owner include/linux/page_owner.h:24 [inline]
> > > > >> free_pages_prepare mm/page_alloc.c:1446 [inline]
> > > > >> free_pcp_prepare+0x254/0x48e mm/page_alloc.c:1496
> > > > >> free_unref_page_prepare mm/page_alloc.c:3369 [inline]
> > > > >> free_unref_page_list+0x11e/0x736 mm/page_alloc.c:3510
> > > > >> release_pages+0x85a/0xbb2 mm/swap.c:1076
> > > > >> free_pages_and_swap_cache+0x76/0x88 mm/swap_state.c:311
> > > > >> tlb_batch_pages_flush+0x86/0x10c mm/mmu_gather.c:97
> > > > >> tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
> > > > >> tlb_flush_mmu mm/mmu_gather.c:299 [inline]
> > > > >> tlb_finish_mmu+0xcc/0x280 mm/mmu_gather.c:391
> > > > >> exit_mmap+0x190/0x686 mm/mmap.c:3096
> > > > >> __mmput+0x98/0x290 kernel/fork.c:1207
> > > > >> mmput+0x74/0x88 kernel/fork.c:1229
> > > > >> exit_mm kernel/exit.c:563 [inline]
> > > > >> do_exit+0x602/0x17be kernel/exit.c:854
> > > > >> do_group_exit+0x8e/0x15e kernel/exit.c:1012
> > > > >> __do_sys_exit_group kernel/exit.c:1023 [inline]
> > > > >> __wake_up_parent+0x0/0x4a kernel/exit.c:1021
> > > > >> ret_from_syscall+0x0/0x2
> > > > >>
> > > > >> Memory state around the buggy address:
> > > > >> ff200000030a7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > > > >> ff200000030a7900: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2
> > > > >>> ff200000030a7980: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
> > > > >> ^
> > > > >> ff200000030a7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > > > >> ff200000030a7a80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
> > > > >> ==================================================================
> > > > >>
> > > > >>
> > > > >> ---
> > > > >> This report is generated by a bot. It may contain errors.
> > > > >> See https://goo.gl/tpsmEJ for more information about syzbot.
> > > > >> syzbot engineers can be reached at [email protected].
> > > > >>
> > > > >> syzbot will keep track of this issue. See:
> > > > >> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> > > > >>
> > > > >> If the bug is already fixed, let syzbot know by replying with:
> > > > >> #syz fix: exact-commit-title
> > > > >>
> > > > >> If you want to change bug's subsystems, reply with:
> > > > >> #syz set subsystems: new-subsystem
> > > > >> (See the list of subsystem names on the web dashboard)
> > > > >>
> > > > >> If the bug is a duplicate of another bug, reply with:
> > > > >> #syz dup: exact-subject-of-another-report
> > > > >>
> > > > >> If you want to undo deduplication, reply with:
> > > > >> #syz undup
> > > > >>
> > > > >> --
> > > > >> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> > > > >> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> > > > >> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/00000000000084706805fab08e27%40google.com.
> > > > > _______________________________________________
> > > > > linux-riscv mailing list
> > > > > [email protected]
> > > > > http://lists.infradead.org/mailman/listinfo/linux-riscv