Hello,
syzbot found the following issue on:
HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=111a5a86480000
kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5
dashboard link: https://syzkaller.appspot.com/bug?extid=01db4d8aed628ede44b1
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8111a570d6cb/disk-0a093b28.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ecc135b7fc9a/vmlinux-0a093b28.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ca8d73b446ea/bzImage-0a093b28.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
==================================================================
BUG: KASAN: use-after-free in __io_req_task_work_add+0x6b4/0x760 io_uring/io_uring.c:1287
Read of size 8 at addr ffff888027236018 by task syz-executor.3/11047
CPU: 0 PID: 11047 Comm: syz-executor.3 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:306 [inline]
print_report+0x15e/0x45d mm/kasan/report.c:417
kasan_report+0xc0/0xf0 mm/kasan/report.c:517
__io_req_task_work_add+0x6b4/0x760 io_uring/io_uring.c:1287
io_req_task_work_add io_uring/io_uring.h:95 [inline]
__io_poll_execute io_uring/poll.c:366 [inline]
io_poll_execute.constprop.0+0x15b/0x190 io_uring/poll.c:372
io_poll_cancel_req io_uring/poll.c:379 [inline]
io_poll_remove_all_table+0x26d/0x2bd io_uring/poll.c:741
io_poll_remove_all+0x2e/0x4b io_uring/poll.c:759
io_ring_ctx_wait_and_kill+0x1a0/0x340 io_uring/io_uring.c:3017
io_uring_release+0x46/0x4a io_uring/io_uring.c:3042
__fput+0x27c/0xa90 fs/file_table.c:321
task_work_run+0x16f/0x270 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xb17/0x2a90 kernel/exit.c:867
do_group_exit+0xd4/0x2a0 kernel/exit.c:1012
__do_sys_exit_group kernel/exit.c:1023 [inline]
__se_sys_exit_group kernel/exit.c:1021 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1021
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd01608c0c9
Code: Unable to access opcode bytes at 0x7fd01608c09f.
RSP: 002b:00007ffe4aaf8e78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007fd01608c0c9
RDX: 00007fd01603df7b RSI: ffffffffffffffb8 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000023b38e02 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffe4aaf8f60
</TASK>
Allocated by task 11047:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
__kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:325
kasan_slab_alloc include/linux/kasan.h:186 [inline]
slab_post_alloc_hook mm/slab.h:769 [inline]
slab_alloc_node mm/slub.c:3452 [inline]
kmem_cache_alloc_node+0x183/0x350 mm/slub.c:3497
alloc_task_struct_node kernel/fork.c:171 [inline]
dup_task_struct kernel/fork.c:979 [inline]
copy_process+0x3aa/0x7740 kernel/fork.c:2103
kernel_clone+0xeb/0x9a0 kernel/fork.c:2687
__do_sys_clone+0xba/0x100 kernel/fork.c:2828
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 15:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
kasan_slab_free include/linux/kasan.h:162 [inline]
slab_free_hook mm/slub.c:1781 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
slab_free mm/slub.c:3787 [inline]
kmem_cache_free+0xec/0x4e0 mm/slub.c:3809
put_task_struct include/linux/sched/task.h:119 [inline]
delayed_put_task_struct+0x26e/0x3f0 kernel/exit.c:225
rcu_do_batch kernel/rcu/tree.c:2113 [inline]
rcu_core+0x821/0x1920 kernel/rcu/tree.c:2373
__do_softirq+0x1fb/0xaf6 kernel/softirq.c:571
Last potentially related work creation:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
__kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
__call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2622
put_task_struct_rcu_user+0x83/0xc0 kernel/exit.c:231
context_switch kernel/sched/core.c:5304 [inline]
__schedule+0x25d8/0x5a70 kernel/sched/core.c:6619
preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6788
preempt_schedule_thunk+0x1a/0x20 arch/x86/entry/thunk_64.S:34
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irq+0x40/0x50 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:400 [inline]
do_group_exit+0x1c5/0x2a0 kernel/exit.c:1009
__do_sys_exit_group kernel/exit.c:1023 [inline]
__se_sys_exit_group kernel/exit.c:1021 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1021
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Second to last potentially related work creation:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
__kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
__call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2622
put_task_struct_rcu_user+0x83/0xc0 kernel/exit.c:231
release_task+0xcc8/0x1870 kernel/exit.c:281
wait_task_zombie kernel/exit.c:1198 [inline]
wait_consider_task+0x306d/0x3ce0 kernel/exit.c:1425
do_wait_thread kernel/exit.c:1488 [inline]
do_wait+0x7cd/0xd90 kernel/exit.c:1605
kernel_wait4+0x150/0x260 kernel/exit.c:1768
__do_sys_wait4+0x13f/0x150 kernel/exit.c:1796
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff8880272357c0
which belongs to the cache task_struct of size 7232
The buggy address is located 2136 bytes inside of
7232-byte region [ffff8880272357c0, ffff888027237400)
The buggy address belongs to the physical page:
page:ffffea00009c8c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27230
head:ffffea00009c8c00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880219a5c01
ksm flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffff8880125ec500 ffffea0000ab3800 dead000000000003
raw: 0000000000000000 0000000000040004 00000001ffffffff ffff8880219a5c01
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 56, tgid 56 (kworker/u4:4), ts 11164250893, free_ts 0
prep_new_page mm/page_alloc.c:2549 [inline]
get_page_from_freelist+0x11bb/0x2d50 mm/page_alloc.c:4324
__alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5590
alloc_pages+0x1aa/0x270 mm/mempolicy.c:2281
alloc_slab_page mm/slub.c:1851 [inline]
allocate_slab+0x25f/0x350 mm/slub.c:1998
new_slab mm/slub.c:2051 [inline]
___slab_alloc+0xa91/0x1400 mm/slub.c:3193
__slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292
__slab_alloc_node mm/slub.c:3345 [inline]
slab_alloc_node mm/slub.c:3442 [inline]
kmem_cache_alloc_node+0x136/0x350 mm/slub.c:3497
alloc_task_struct_node kernel/fork.c:171 [inline]
dup_task_struct kernel/fork.c:979 [inline]
copy_process+0x3aa/0x7740 kernel/fork.c:2103
kernel_clone+0xeb/0x9a0 kernel/fork.c:2687
user_mode_thread+0xb1/0xf0 kernel/fork.c:2763
call_usermodehelper_exec_work kernel/umh.c:175 [inline]
call_usermodehelper_exec_work+0xd0/0x180 kernel/umh.c:161
process_one_work+0x9bf/0x1750 kernel/workqueue.c:2293
worker_thread+0x669/0x1090 kernel/workqueue.c:2440
kthread+0x2e8/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
page_owner free stack trace missing
Memory state around the buggy address:
ffff888027235f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888027235f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888027236000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888027236080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888027236100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
This report is generated by a bot. It may contain errors.
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> On 1/12/23 10:26, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112
>> git tree: linux-next
>> console output: https://syzkaller.appspot.com/x/log.txt?x=111a5a86480000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5
>> dashboard link: https://syzkaller.appspot.com/bug?extid=01db4d8aed628ede44b1
>> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>>
>> Unfortunately, I don't have any reproducer for this issue yet.
>
> #syz test: git://git.kernel.dk/linux.git syztest
This crash does not have a reproducer. I cannot test it.
>
>>
>> Downloadable assets:
>> disk image: https://storage.googleapis.com/syzbot-assets/8111a570d6cb/disk-0a093b28.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/ecc135b7fc9a/vmlinux-0a093b28.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/ca8d73b446ea/bzImage-0a093b28.xz
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: [email protected]
>>
>> ==================================================================
>> BUG: KASAN: use-after-free in __io_req_task_work_add+0x6b4/0x760 io_uring/io_uring.c:1287
>> Read of size 8 at addr ffff888027236018 by task syz-executor.3/11047
>>
>> CPU: 0 PID: 11047 Comm: syz-executor.3 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
>> Call Trace:
>> <TASK>
>> __dump_stack lib/dump_stack.c:88 [inline]
>> dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
>> print_address_description mm/kasan/report.c:306 [inline]
>> print_report+0x15e/0x45d mm/kasan/report.c:417
>> kasan_report+0xc0/0xf0 mm/kasan/report.c:517
>> __io_req_task_work_add+0x6b4/0x760 io_uring/io_uring.c:1287
>> io_req_task_work_add io_uring/io_uring.h:95 [inline]
>> __io_poll_execute io_uring/poll.c:366 [inline]
>> io_poll_execute.constprop.0+0x15b/0x190 io_uring/poll.c:372
>> io_poll_cancel_req io_uring/poll.c:379 [inline]
>> io_poll_remove_all_table+0x26d/0x2bd io_uring/poll.c:741
>> io_poll_remove_all+0x2e/0x4b io_uring/poll.c:759
>> io_ring_ctx_wait_and_kill+0x1a0/0x340 io_uring/io_uring.c:3017
>> io_uring_release+0x46/0x4a io_uring/io_uring.c:3042
>> __fput+0x27c/0xa90 fs/file_table.c:321
>> task_work_run+0x16f/0x270 kernel/task_work.c:179
>> exit_task_work include/linux/task_work.h:38 [inline]
>> do_exit+0xb17/0x2a90 kernel/exit.c:867
>> do_group_exit+0xd4/0x2a0 kernel/exit.c:1012
>> __do_sys_exit_group kernel/exit.c:1023 [inline]
>> __se_sys_exit_group kernel/exit.c:1021 [inline]
>> __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1021
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>> RIP: 0033:0x7fd01608c0c9
>> Code: Unable to access opcode bytes at 0x7fd01608c09f.
>> RSP: 002b:00007ffe4aaf8e78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
>> RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007fd01608c0c9
>> RDX: 00007fd01603df7b RSI: ffffffffffffffb8 RDI: 0000000000000000
>> RBP: 0000000000000000 R08: 0000000023b38e02 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
>> R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffe4aaf8f60
>> </TASK>
>>
>> Allocated by task 11047:
>> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
>> kasan_set_track+0x25/0x30 mm/kasan/common.c:52
>> __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:325
>> kasan_slab_alloc include/linux/kasan.h:186 [inline]
>> slab_post_alloc_hook mm/slab.h:769 [inline]
>> slab_alloc_node mm/slub.c:3452 [inline]
>> kmem_cache_alloc_node+0x183/0x350 mm/slub.c:3497
>> alloc_task_struct_node kernel/fork.c:171 [inline]
>> dup_task_struct kernel/fork.c:979 [inline]
>> copy_process+0x3aa/0x7740 kernel/fork.c:2103
>> kernel_clone+0xeb/0x9a0 kernel/fork.c:2687
>> __do_sys_clone+0xba/0x100 kernel/fork.c:2828
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>>
>> Freed by task 15:
>> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
>> kasan_set_track+0x25/0x30 mm/kasan/common.c:52
>> kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518
>> ____kasan_slab_free mm/kasan/common.c:236 [inline]
>> ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
>> kasan_slab_free include/linux/kasan.h:162 [inline]
>> slab_free_hook mm/slub.c:1781 [inline]
>> slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
>> slab_free mm/slub.c:3787 [inline]
>> kmem_cache_free+0xec/0x4e0 mm/slub.c:3809
>> put_task_struct include/linux/sched/task.h:119 [inline]
>> delayed_put_task_struct+0x26e/0x3f0 kernel/exit.c:225
>> rcu_do_batch kernel/rcu/tree.c:2113 [inline]
>> rcu_core+0x821/0x1920 kernel/rcu/tree.c:2373
>> __do_softirq+0x1fb/0xaf6 kernel/softirq.c:571
>>
>> Last potentially related work creation:
>> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
>> __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
>> __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2622
>> put_task_struct_rcu_user+0x83/0xc0 kernel/exit.c:231
>> context_switch kernel/sched/core.c:5304 [inline]
>> __schedule+0x25d8/0x5a70 kernel/sched/core.c:6619
>> preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6788
>> preempt_schedule_thunk+0x1a/0x20 arch/x86/entry/thunk_64.S:34
>> __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
>> _raw_spin_unlock_irq+0x40/0x50 kernel/locking/spinlock.c:202
>> spin_unlock_irq include/linux/spinlock.h:400 [inline]
>> do_group_exit+0x1c5/0x2a0 kernel/exit.c:1009
>> __do_sys_exit_group kernel/exit.c:1023 [inline]
>> __se_sys_exit_group kernel/exit.c:1021 [inline]
>> __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1021
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>>
>> Second to last potentially related work creation:
>> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
>> __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
>> __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2622
>> put_task_struct_rcu_user+0x83/0xc0 kernel/exit.c:231
>> release_task+0xcc8/0x1870 kernel/exit.c:281
>> wait_task_zombie kernel/exit.c:1198 [inline]
>> wait_consider_task+0x306d/0x3ce0 kernel/exit.c:1425
>> do_wait_thread kernel/exit.c:1488 [inline]
>> do_wait+0x7cd/0xd90 kernel/exit.c:1605
>> kernel_wait4+0x150/0x260 kernel/exit.c:1768
>> __do_sys_wait4+0x13f/0x150 kernel/exit.c:1796
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>>
>> The buggy address belongs to the object at ffff8880272357c0
>> which belongs to the cache task_struct of size 7232
>> The buggy address is located 2136 bytes inside of
>> 7232-byte region [ffff8880272357c0, ffff888027237400)
>>
>> The buggy address belongs to the physical page:
>> page:ffffea00009c8c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27230
>> head:ffffea00009c8c00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
>> memcg:ffff8880219a5c01
>> ksm flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
>> raw: 00fff00000010200 ffff8880125ec500 ffffea0000ab3800 dead000000000003
>> raw: 0000000000000000 0000000000040004 00000001ffffffff ffff8880219a5c01
>> page dumped because: kasan: bad access detected
>> page_owner tracks the page as allocated
>> page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 56, tgid 56 (kworker/u4:4), ts 11164250893, free_ts 0
>> prep_new_page mm/page_alloc.c:2549 [inline]
>> get_page_from_freelist+0x11bb/0x2d50 mm/page_alloc.c:4324
>> __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5590
>> alloc_pages+0x1aa/0x270 mm/mempolicy.c:2281
>> alloc_slab_page mm/slub.c:1851 [inline]
>> allocate_slab+0x25f/0x350 mm/slub.c:1998
>> new_slab mm/slub.c:2051 [inline]
>> ___slab_alloc+0xa91/0x1400 mm/slub.c:3193
>> __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292
>> __slab_alloc_node mm/slub.c:3345 [inline]
>> slab_alloc_node mm/slub.c:3442 [inline]
>> kmem_cache_alloc_node+0x136/0x350 mm/slub.c:3497
>> alloc_task_struct_node kernel/fork.c:171 [inline]
>> dup_task_struct kernel/fork.c:979 [inline]
>> copy_process+0x3aa/0x7740 kernel/fork.c:2103
>> kernel_clone+0xeb/0x9a0 kernel/fork.c:2687
>> user_mode_thread+0xb1/0xf0 kernel/fork.c:2763
>> call_usermodehelper_exec_work kernel/umh.c:175 [inline]
>> call_usermodehelper_exec_work+0xd0/0x180 kernel/umh.c:161
>> process_one_work+0x9bf/0x1750 kernel/workqueue.c:2293
>> worker_thread+0x669/0x1090 kernel/workqueue.c:2440
>> kthread+0x2e8/0x3a0 kernel/kthread.c:376
>> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
>> page_owner free stack trace missing
>>
>> Memory state around the buggy address:
>> ffff888027235f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff888027235f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>> ffff888027236000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ^
>> ffff888027236080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff888027236100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ==================================================================
>>
>>
>> ---
>> 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.
>
> --
> Pavel Begunkov
On 1/12/23 10:26, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=111a5a86480000
> kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5
> dashboard link: https://syzkaller.appspot.com/bug?extid=01db4d8aed628ede44b1
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>
> Unfortunately, I don't have any reproducer for this issue yet.
#syz test: git://git.kernel.dk/linux.git syztest
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/8111a570d6cb/disk-0a093b28.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/ecc135b7fc9a/vmlinux-0a093b28.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/ca8d73b446ea/bzImage-0a093b28.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
>
> ==================================================================
> BUG: KASAN: use-after-free in __io_req_task_work_add+0x6b4/0x760 io_uring/io_uring.c:1287
> Read of size 8 at addr ffff888027236018 by task syz-executor.3/11047
>
> CPU: 0 PID: 11047 Comm: syz-executor.3 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
> Call Trace:
> <TASK>
> __dump_stack lib/dump_stack.c:88 [inline]
> dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
> print_address_description mm/kasan/report.c:306 [inline]
> print_report+0x15e/0x45d mm/kasan/report.c:417
> kasan_report+0xc0/0xf0 mm/kasan/report.c:517
> __io_req_task_work_add+0x6b4/0x760 io_uring/io_uring.c:1287
> io_req_task_work_add io_uring/io_uring.h:95 [inline]
> __io_poll_execute io_uring/poll.c:366 [inline]
> io_poll_execute.constprop.0+0x15b/0x190 io_uring/poll.c:372
> io_poll_cancel_req io_uring/poll.c:379 [inline]
> io_poll_remove_all_table+0x26d/0x2bd io_uring/poll.c:741
> io_poll_remove_all+0x2e/0x4b io_uring/poll.c:759
> io_ring_ctx_wait_and_kill+0x1a0/0x340 io_uring/io_uring.c:3017
> io_uring_release+0x46/0x4a io_uring/io_uring.c:3042
> __fput+0x27c/0xa90 fs/file_table.c:321
> task_work_run+0x16f/0x270 kernel/task_work.c:179
> exit_task_work include/linux/task_work.h:38 [inline]
> do_exit+0xb17/0x2a90 kernel/exit.c:867
> do_group_exit+0xd4/0x2a0 kernel/exit.c:1012
> __do_sys_exit_group kernel/exit.c:1023 [inline]
> __se_sys_exit_group kernel/exit.c:1021 [inline]
> __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1021
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7fd01608c0c9
> Code: Unable to access opcode bytes at 0x7fd01608c09f.
> RSP: 002b:00007ffe4aaf8e78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
> RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007fd01608c0c9
> RDX: 00007fd01603df7b RSI: ffffffffffffffb8 RDI: 0000000000000000
> RBP: 0000000000000000 R08: 0000000023b38e02 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
> R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffe4aaf8f60
> </TASK>
>
> Allocated by task 11047:
> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
> kasan_set_track+0x25/0x30 mm/kasan/common.c:52
> __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:325
> kasan_slab_alloc include/linux/kasan.h:186 [inline]
> slab_post_alloc_hook mm/slab.h:769 [inline]
> slab_alloc_node mm/slub.c:3452 [inline]
> kmem_cache_alloc_node+0x183/0x350 mm/slub.c:3497
> alloc_task_struct_node kernel/fork.c:171 [inline]
> dup_task_struct kernel/fork.c:979 [inline]
> copy_process+0x3aa/0x7740 kernel/fork.c:2103
> kernel_clone+0xeb/0x9a0 kernel/fork.c:2687
> __do_sys_clone+0xba/0x100 kernel/fork.c:2828
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> Freed by task 15:
> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
> kasan_set_track+0x25/0x30 mm/kasan/common.c:52
> kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518
> ____kasan_slab_free mm/kasan/common.c:236 [inline]
> ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
> kasan_slab_free include/linux/kasan.h:162 [inline]
> slab_free_hook mm/slub.c:1781 [inline]
> slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
> slab_free mm/slub.c:3787 [inline]
> kmem_cache_free+0xec/0x4e0 mm/slub.c:3809
> put_task_struct include/linux/sched/task.h:119 [inline]
> delayed_put_task_struct+0x26e/0x3f0 kernel/exit.c:225
> rcu_do_batch kernel/rcu/tree.c:2113 [inline]
> rcu_core+0x821/0x1920 kernel/rcu/tree.c:2373
> __do_softirq+0x1fb/0xaf6 kernel/softirq.c:571
>
> Last potentially related work creation:
> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
> __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
> __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2622
> put_task_struct_rcu_user+0x83/0xc0 kernel/exit.c:231
> context_switch kernel/sched/core.c:5304 [inline]
> __schedule+0x25d8/0x5a70 kernel/sched/core.c:6619
> preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6788
> preempt_schedule_thunk+0x1a/0x20 arch/x86/entry/thunk_64.S:34
> __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
> _raw_spin_unlock_irq+0x40/0x50 kernel/locking/spinlock.c:202
> spin_unlock_irq include/linux/spinlock.h:400 [inline]
> do_group_exit+0x1c5/0x2a0 kernel/exit.c:1009
> __do_sys_exit_group kernel/exit.c:1023 [inline]
> __se_sys_exit_group kernel/exit.c:1021 [inline]
> __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1021
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> Second to last potentially related work creation:
> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
> __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
> __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2622
> put_task_struct_rcu_user+0x83/0xc0 kernel/exit.c:231
> release_task+0xcc8/0x1870 kernel/exit.c:281
> wait_task_zombie kernel/exit.c:1198 [inline]
> wait_consider_task+0x306d/0x3ce0 kernel/exit.c:1425
> do_wait_thread kernel/exit.c:1488 [inline]
> do_wait+0x7cd/0xd90 kernel/exit.c:1605
> kernel_wait4+0x150/0x260 kernel/exit.c:1768
> __do_sys_wait4+0x13f/0x150 kernel/exit.c:1796
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> The buggy address belongs to the object at ffff8880272357c0
> which belongs to the cache task_struct of size 7232
> The buggy address is located 2136 bytes inside of
> 7232-byte region [ffff8880272357c0, ffff888027237400)
>
> The buggy address belongs to the physical page:
> page:ffffea00009c8c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27230
> head:ffffea00009c8c00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> memcg:ffff8880219a5c01
> ksm flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
> raw: 00fff00000010200 ffff8880125ec500 ffffea0000ab3800 dead000000000003
> raw: 0000000000000000 0000000000040004 00000001ffffffff ffff8880219a5c01
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 56, tgid 56 (kworker/u4:4), ts 11164250893, free_ts 0
> prep_new_page mm/page_alloc.c:2549 [inline]
> get_page_from_freelist+0x11bb/0x2d50 mm/page_alloc.c:4324
> __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5590
> alloc_pages+0x1aa/0x270 mm/mempolicy.c:2281
> alloc_slab_page mm/slub.c:1851 [inline]
> allocate_slab+0x25f/0x350 mm/slub.c:1998
> new_slab mm/slub.c:2051 [inline]
> ___slab_alloc+0xa91/0x1400 mm/slub.c:3193
> __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292
> __slab_alloc_node mm/slub.c:3345 [inline]
> slab_alloc_node mm/slub.c:3442 [inline]
> kmem_cache_alloc_node+0x136/0x350 mm/slub.c:3497
> alloc_task_struct_node kernel/fork.c:171 [inline]
> dup_task_struct kernel/fork.c:979 [inline]
> copy_process+0x3aa/0x7740 kernel/fork.c:2103
> kernel_clone+0xeb/0x9a0 kernel/fork.c:2687
> user_mode_thread+0xb1/0xf0 kernel/fork.c:2763
> call_usermodehelper_exec_work kernel/umh.c:175 [inline]
> call_usermodehelper_exec_work+0xd0/0x180 kernel/umh.c:161
> process_one_work+0x9bf/0x1750 kernel/workqueue.c:2293
> worker_thread+0x669/0x1090 kernel/workqueue.c:2440
> kthread+0x2e8/0x3a0 kernel/kthread.c:376
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
> page_owner free stack trace missing
>
> Memory state around the buggy address:
> ffff888027235f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff888027235f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff888027236000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff888027236080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff888027236100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> 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.
--
Pavel Begunkov
> On 1/12/23 3:26 AM, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112
>> git tree: linux-next
>> console output: https://syzkaller.appspot.com/x/log.txt?x=111a5a86480000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5
>> dashboard link: https://syzkaller.appspot.com/bug?extid=01db4d8aed628ede44b1
>> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>>
>> Unfortunately, I don't have any reproducer for this issue yet.
>
> #syz test: git://git.kernel.dk/linux.git for-next
This crash does not have a reproducer. I cannot test it.
>
> --
> Jens Axboe
>
>
On 1/12/23 3:26 AM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=111a5a86480000
> kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5
> dashboard link: https://syzkaller.appspot.com/bug?extid=01db4d8aed628ede44b1
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>
> Unfortunately, I don't have any reproducer for this issue yet.
#syz test: git://git.kernel.dk/linux.git for-next
--
Jens Axboe