Hello,
syzbot found the following issue on:
HEAD commit: dc1a9bf2 octeontx2-pf: Add UDP segmentation offload support
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16ff67de900000
kernel config: https://syzkaller.appspot.com/x/.config?x=b6856d16f78d8fa9
dashboard link: https://syzkaller.appspot.com/bug?extid=5334f62e4d22804e646a
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12e9f279900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=125f3e1e900000
The issue was bisected to:
commit a1132430c2c55af62d13e9fca752d46f14d548b3
Author: Magnus Karlsson <[email protected]>
Date: Fri Aug 28 08:26:26 2020 +0000
xsk: Add shared umem support between devices
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10a373de900000
final oops: https://syzkaller.appspot.com/x/report.txt?x=12a373de900000
console output: https://syzkaller.appspot.com/x/log.txt?x=14a373de900000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
Fixes: a1132430c2c5 ("xsk: Add shared umem support between devices")
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:71 [inline]
BUG: KASAN: use-after-free in atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline]
BUG: KASAN: use-after-free in refcount_sub_and_test include/linux/refcount.h:266 [inline]
BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:294 [inline]
BUG: KASAN: use-after-free in xp_put_pool+0x2c/0x1e0 net/xdp/xsk_buff_pool.c:262
Write of size 4 at addr ffff8880a6a4d860 by task ksoftirqd/0/9
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x18f/0x20d lib/dump_stack.c:118
print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
check_memory_region_inline mm/kasan/generic.c:186 [inline]
check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
instrument_atomic_write include/linux/instrumented.h:71 [inline]
atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline]
refcount_sub_and_test include/linux/refcount.h:266 [inline]
refcount_dec_and_test include/linux/refcount.h:294 [inline]
xp_put_pool+0x2c/0x1e0 net/xdp/xsk_buff_pool.c:262
xsk_destruct+0x7d/0xa0 net/xdp/xsk.c:1138
__sk_destruct+0x4b/0x860 net/core/sock.c:1764
rcu_do_batch kernel/rcu/tree.c:2428 [inline]
rcu_core+0x5c7/0x1190 kernel/rcu/tree.c:2656
__do_softirq+0x2de/0xa24 kernel/softirq.c:298
run_ksoftirqd kernel/softirq.c:652 [inline]
run_ksoftirqd+0x89/0x100 kernel/softirq.c:644
smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:165
kthread+0x3b5/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Allocated by task 6854:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
kmalloc_node include/linux/slab.h:577 [inline]
kvmalloc_node+0x61/0xf0 mm/util.c:574
kvmalloc include/linux/mm.h:750 [inline]
kvzalloc include/linux/mm.h:758 [inline]
xp_create_and_assign_umem+0x58/0x8d0 net/xdp/xsk_buff_pool.c:54
xsk_bind+0x9a0/0xed0 net/xdp/xsk.c:709
__sys_bind+0x1e9/0x250 net/socket.c:1656
__do_sys_bind net/socket.c:1667 [inline]
__se_sys_bind net/socket.c:1665 [inline]
__x64_sys_bind+0x6f/0xb0 net/socket.c:1665
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Freed by task 6854:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
__kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
__cache_free mm/slab.c:3418 [inline]
kfree+0x103/0x2c0 mm/slab.c:3756
kvfree+0x42/0x50 mm/util.c:603
xp_destroy net/xdp/xsk_buff_pool.c:44 [inline]
xp_destroy+0x45/0x60 net/xdp/xsk_buff_pool.c:38
xsk_bind+0xbdd/0xed0 net/xdp/xsk.c:719
__sys_bind+0x1e9/0x250 net/socket.c:1656
__do_sys_bind net/socket.c:1667 [inline]
__se_sys_bind net/socket.c:1665 [inline]
__x64_sys_bind+0x6f/0xb0 net/socket.c:1665
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff8880a6a4d800
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 96 bytes inside of
1024-byte region [ffff8880a6a4d800, ffff8880a6a4dc00)
The buggy address belongs to the page:
page:00000000dd5fc18f refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa6a4d
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00029cce48 ffffea00025f2148 ffff8880aa040700
raw: 0000000000000000 ffff8880a6a4d000 0000000100000002 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8880a6a4d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880a6a4d780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a6a4d800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880a6a4d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880a6a4d900: 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.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
On 9/2/20 8:57 AM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
Magnus/Bjorn, ptal, thanks!
> HEAD commit: dc1a9bf2 octeontx2-pf: Add UDP segmentation offload support
> git tree: net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=16ff67de900000
> kernel config: https://syzkaller.appspot.com/x/.config?x=b6856d16f78d8fa9
> dashboard link: https://syzkaller.appspot.com/bug?extid=5334f62e4d22804e646a
> compiler: gcc (GCC) 10.1.0-syz 20200507
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12e9f279900000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=125f3e1e900000
>
> The issue was bisected to:
>
> commit a1132430c2c55af62d13e9fca752d46f14d548b3
> Author: Magnus Karlsson <[email protected]>
> Date: Fri Aug 28 08:26:26 2020 +0000
>
> xsk: Add shared umem support between devices
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10a373de900000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=12a373de900000
> console output: https://syzkaller.appspot.com/x/log.txt?x=14a373de900000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
> Fixes: a1132430c2c5 ("xsk: Add shared umem support between devices")
>
> ==================================================================
> BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:71 [inline]
> BUG: KASAN: use-after-free in atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline]
> BUG: KASAN: use-after-free in refcount_sub_and_test include/linux/refcount.h:266 [inline]
> BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:294 [inline]
> BUG: KASAN: use-after-free in xp_put_pool+0x2c/0x1e0 net/xdp/xsk_buff_pool.c:262
> Write of size 4 at addr ffff8880a6a4d860 by task ksoftirqd/0/9
>
> CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.9.0-rc1-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x18f/0x20d lib/dump_stack.c:118
> print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
> __kasan_report mm/kasan/report.c:513 [inline]
> kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
> check_memory_region_inline mm/kasan/generic.c:186 [inline]
> check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
> instrument_atomic_write include/linux/instrumented.h:71 [inline]
> atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline]
> refcount_sub_and_test include/linux/refcount.h:266 [inline]
> refcount_dec_and_test include/linux/refcount.h:294 [inline]
> xp_put_pool+0x2c/0x1e0 net/xdp/xsk_buff_pool.c:262
> xsk_destruct+0x7d/0xa0 net/xdp/xsk.c:1138
> __sk_destruct+0x4b/0x860 net/core/sock.c:1764
> rcu_do_batch kernel/rcu/tree.c:2428 [inline]
> rcu_core+0x5c7/0x1190 kernel/rcu/tree.c:2656
> __do_softirq+0x2de/0xa24 kernel/softirq.c:298
> run_ksoftirqd kernel/softirq.c:652 [inline]
> run_ksoftirqd+0x89/0x100 kernel/softirq.c:644
> smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:165
> kthread+0x3b5/0x4a0 kernel/kthread.c:292
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
>
> Allocated by task 6854:
> kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
> kasan_set_track mm/kasan/common.c:56 [inline]
> __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
> kmalloc_node include/linux/slab.h:577 [inline]
> kvmalloc_node+0x61/0xf0 mm/util.c:574
> kvmalloc include/linux/mm.h:750 [inline]
> kvzalloc include/linux/mm.h:758 [inline]
> xp_create_and_assign_umem+0x58/0x8d0 net/xdp/xsk_buff_pool.c:54
> xsk_bind+0x9a0/0xed0 net/xdp/xsk.c:709
> __sys_bind+0x1e9/0x250 net/socket.c:1656
> __do_sys_bind net/socket.c:1667 [inline]
> __se_sys_bind net/socket.c:1665 [inline]
> __x64_sys_bind+0x6f/0xb0 net/socket.c:1665
> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> Freed by task 6854:
> kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
> kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
> kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
> __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
> __cache_free mm/slab.c:3418 [inline]
> kfree+0x103/0x2c0 mm/slab.c:3756
> kvfree+0x42/0x50 mm/util.c:603
> xp_destroy net/xdp/xsk_buff_pool.c:44 [inline]
> xp_destroy+0x45/0x60 net/xdp/xsk_buff_pool.c:38
> xsk_bind+0xbdd/0xed0 net/xdp/xsk.c:719
> __sys_bind+0x1e9/0x250 net/socket.c:1656
> __do_sys_bind net/socket.c:1667 [inline]
> __se_sys_bind net/socket.c:1665 [inline]
> __x64_sys_bind+0x6f/0xb0 net/socket.c:1665
> do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> The buggy address belongs to the object at ffff8880a6a4d800
> which belongs to the cache kmalloc-1k of size 1024
> The buggy address is located 96 bytes inside of
> 1024-byte region [ffff8880a6a4d800, ffff8880a6a4dc00)
> The buggy address belongs to the page:
> page:00000000dd5fc18f refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa6a4d
> flags: 0xfffe0000000200(slab)
> raw: 00fffe0000000200 ffffea00029cce48 ffffea00025f2148 ffff8880aa040700
> raw: 0000000000000000 ffff8880a6a4d000 0000000100000002 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff8880a6a4d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8880a6a4d780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>> ffff8880a6a4d800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff8880a6a4d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8880a6a4d900: 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.
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> syzbot can test patches for this issue, for details see:
> https://goo.gl/tpsmEJ#testing-patches
>
> -----Original Message-----
> From: Daniel Borkmann <[email protected]>
> Sent: Wednesday, September 2, 2020 9:06 AM
> To: syzbot <[email protected]>;
> [email protected]; [email protected]; [email protected]; Topel, Bjorn
> <[email protected]>; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; linux-
> [email protected]; Karlsson, Magnus <[email protected]>;
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; syzkaller-
> [email protected]; [email protected]; [email protected]
> Subject: Re: KASAN: use-after-free Write in xp_put_pool
>
> On 9/2/20 8:57 AM, syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
>
> Magnus/Bjorn, ptal, thanks!
On it as we speak.
> > HEAD commit: dc1a9bf2 octeontx2-pf: Add UDP segmentation offload
> support
> > git tree: net-next
> > console output:
> > https://syzkaller.appspot.com/x/log.txt?x=16ff67de900000
> > kernel config:
> > https://syzkaller.appspot.com/x/.config?x=b6856d16f78d8fa9
> > dashboard link:
> https://syzkaller.appspot.com/bug?extid=5334f62e4d22804e646a
> > compiler: gcc (GCC) 10.1.0-syz 20200507
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12e9f279900000
> > C reproducer:
> https://syzkaller.appspot.com/x/repro.c?x=125f3e1e900000
> >
> > The issue was bisected to:
> >
> > commit a1132430c2c55af62d13e9fca752d46f14d548b3
> > Author: Magnus Karlsson <[email protected]>
> > Date: Fri Aug 28 08:26:26 2020 +0000
> >
> > xsk: Add shared umem support between devices
> >
> > bisection log:
> https://syzkaller.appspot.com/x/bisect.txt?x=10a373de900000
> > final oops:
> https://syzkaller.appspot.com/x/report.txt?x=12a373de900000
> > console output:
> > https://syzkaller.appspot.com/x/log.txt?x=14a373de900000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the
> commit:
> > Reported-by: [email protected]
> > Fixes: a1132430c2c5 ("xsk: Add shared umem support between devices")
> >
> >
> ==========================================================
> ========
> > BUG: KASAN: use-after-free in instrument_atomic_write
> > include/linux/instrumented.h:71 [inline]
> > BUG: KASAN: use-after-free in atomic_fetch_sub_release
> > include/asm-generic/atomic-instrumented.h:220 [inline]
> > BUG: KASAN: use-after-free in refcount_sub_and_test
> > include/linux/refcount.h:266 [inline]
> > BUG: KASAN: use-after-free in refcount_dec_and_test
> > include/linux/refcount.h:294 [inline]
> > BUG: KASAN: use-after-free in xp_put_pool+0x2c/0x1e0
> > net/xdp/xsk_buff_pool.c:262 Write of size 4 at addr ffff8880a6a4d860
> > by task ksoftirqd/0/9
> >
> > CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.9.0-rc1-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine,
> > BIOS Google 01/01/2011 Call Trace:
> > __dump_stack lib/dump_stack.c:77 [inline]
> > dump_stack+0x18f/0x20d lib/dump_stack.c:118
> > print_address_description.constprop.0.cold+0xae/0x497
> mm/kasan/report.c:383
> > __kasan_report mm/kasan/report.c:513 [inline]
> > kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
> > check_memory_region_inline mm/kasan/generic.c:186 [inline]
> > check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
> > instrument_atomic_write include/linux/instrumented.h:71 [inline]
> > atomic_fetch_sub_release include/asm-generic/atomic-
> instrumented.h:220 [inline]
> > refcount_sub_and_test include/linux/refcount.h:266 [inline]
> > refcount_dec_and_test include/linux/refcount.h:294 [inline]
> > xp_put_pool+0x2c/0x1e0 net/xdp/xsk_buff_pool.c:262
> > xsk_destruct+0x7d/0xa0 net/xdp/xsk.c:1138
> > __sk_destruct+0x4b/0x860 net/core/sock.c:1764
> > rcu_do_batch kernel/rcu/tree.c:2428 [inline]
> > rcu_core+0x5c7/0x1190 kernel/rcu/tree.c:2656
> > __do_softirq+0x2de/0xa24 kernel/softirq.c:298
> > run_ksoftirqd kernel/softirq.c:652 [inline]
> > run_ksoftirqd+0x89/0x100 kernel/softirq.c:644
> > smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:165
> > kthread+0x3b5/0x4a0 kernel/kthread.c:292
> > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
> >
> > Allocated by task 6854:
> > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
> > kasan_set_track mm/kasan/common.c:56 [inline]
> > __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
> > kmalloc_node include/linux/slab.h:577 [inline]
> > kvmalloc_node+0x61/0xf0 mm/util.c:574
> > kvmalloc include/linux/mm.h:750 [inline]
> > kvzalloc include/linux/mm.h:758 [inline]
> > xp_create_and_assign_umem+0x58/0x8d0 net/xdp/xsk_buff_pool.c:54
> > xsk_bind+0x9a0/0xed0 net/xdp/xsk.c:709
> > __sys_bind+0x1e9/0x250 net/socket.c:1656
> > __do_sys_bind net/socket.c:1667 [inline]
> > __se_sys_bind net/socket.c:1665 [inline]
> > __x64_sys_bind+0x6f/0xb0 net/socket.c:1665
> > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
> > entry_SYSCALL_64_after_hwframe+0x44/0xa9
> >
> > Freed by task 6854:
> > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
> > kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
> > kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
> > __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
> > __cache_free mm/slab.c:3418 [inline]
> > kfree+0x103/0x2c0 mm/slab.c:3756
> > kvfree+0x42/0x50 mm/util.c:603
> > xp_destroy net/xdp/xsk_buff_pool.c:44 [inline]
> > xp_destroy+0x45/0x60 net/xdp/xsk_buff_pool.c:38
> > xsk_bind+0xbdd/0xed0 net/xdp/xsk.c:719
> > __sys_bind+0x1e9/0x250 net/socket.c:1656
> > __do_sys_bind net/socket.c:1667 [inline]
> > __se_sys_bind net/socket.c:1665 [inline]
> > __x64_sys_bind+0x6f/0xb0 net/socket.c:1665
> > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
> > entry_SYSCALL_64_after_hwframe+0x44/0xa9
> >
> > The buggy address belongs to the object at ffff8880a6a4d800
> > which belongs to the cache kmalloc-1k of size 1024 The buggy address
> > is located 96 bytes inside of
> > 1024-byte region [ffff8880a6a4d800, ffff8880a6a4dc00) The buggy
> > address belongs to the page:
> > page:00000000dd5fc18f refcount:1 mapcount:0 mapping:0000000000000000
> > index:0x0 pfn:0xa6a4d
> > flags: 0xfffe0000000200(slab)
> > raw: 00fffe0000000200 ffffea00029cce48 ffffea00025f2148
> > ffff8880aa040700
> > raw: 0000000000000000 ffff8880a6a4d000 0000000100000002
> > 0000000000000000 page dumped because: kasan: bad access detected
> >
> > Memory state around the buggy address:
> > ffff8880a6a4d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> > ffff8880a6a4d780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> >> ffff8880a6a4d800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ^
> > ffff8880a6a4d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff8880a6a4d900: 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.
> > For information about bisection process see:
> > https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for
> details see:
> > https://goo.gl/tpsmEJ#testing-patches
> >
On Wed, Sep 2, 2020 at 9:06 AM Daniel Borkmann <[email protected]> wrote:
>
> On 9/2/20 8:57 AM, syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
>
> Magnus/Bjorn, ptal, thanks!
On it as we speak.
> > HEAD commit: dc1a9bf2 octeontx2-pf: Add UDP segmentation offload support
> > git tree: net-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=16ff67de900000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=b6856d16f78d8fa9
> > dashboard link: https://syzkaller.appspot.com/bug?extid=5334f62e4d22804e646a
> > compiler: gcc (GCC) 10.1.0-syz 20200507
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12e9f279900000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=125f3e1e900000
> >
> > The issue was bisected to:
> >
> > commit a1132430c2c55af62d13e9fca752d46f14d548b3
> > Author: Magnus Karlsson <[email protected]>
> > Date: Fri Aug 28 08:26:26 2020 +0000
> >
> > xsk: Add shared umem support between devices
> >
> > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10a373de900000
> > final oops: https://syzkaller.appspot.com/x/report.txt?x=12a373de900000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=14a373de900000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: [email protected]
> > Fixes: a1132430c2c5 ("xsk: Add shared umem support between devices")
> >
> > ==================================================================
> > BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:71 [inline]
> > BUG: KASAN: use-after-free in atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline]
> > BUG: KASAN: use-after-free in refcount_sub_and_test include/linux/refcount.h:266 [inline]
> > BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:294 [inline]
> > BUG: KASAN: use-after-free in xp_put_pool+0x2c/0x1e0 net/xdp/xsk_buff_pool.c:262
> > Write of size 4 at addr ffff8880a6a4d860 by task ksoftirqd/0/9
> >
> > CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.9.0-rc1-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > Call Trace:
> > __dump_stack lib/dump_stack.c:77 [inline]
> > dump_stack+0x18f/0x20d lib/dump_stack.c:118
> > print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
> > __kasan_report mm/kasan/report.c:513 [inline]
> > kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
> > check_memory_region_inline mm/kasan/generic.c:186 [inline]
> > check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
> > instrument_atomic_write include/linux/instrumented.h:71 [inline]
> > atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline]
> > refcount_sub_and_test include/linux/refcount.h:266 [inline]
> > refcount_dec_and_test include/linux/refcount.h:294 [inline]
> > xp_put_pool+0x2c/0x1e0 net/xdp/xsk_buff_pool.c:262
> > xsk_destruct+0x7d/0xa0 net/xdp/xsk.c:1138
> > __sk_destruct+0x4b/0x860 net/core/sock.c:1764
> > rcu_do_batch kernel/rcu/tree.c:2428 [inline]
> > rcu_core+0x5c7/0x1190 kernel/rcu/tree.c:2656
> > __do_softirq+0x2de/0xa24 kernel/softirq.c:298
> > run_ksoftirqd kernel/softirq.c:652 [inline]
> > run_ksoftirqd+0x89/0x100 kernel/softirq.c:644
> > smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:165
> > kthread+0x3b5/0x4a0 kernel/kthread.c:292
> > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
> >
> > Allocated by task 6854:
> > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
> > kasan_set_track mm/kasan/common.c:56 [inline]
> > __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
> > kmalloc_node include/linux/slab.h:577 [inline]
> > kvmalloc_node+0x61/0xf0 mm/util.c:574
> > kvmalloc include/linux/mm.h:750 [inline]
> > kvzalloc include/linux/mm.h:758 [inline]
> > xp_create_and_assign_umem+0x58/0x8d0 net/xdp/xsk_buff_pool.c:54
> > xsk_bind+0x9a0/0xed0 net/xdp/xsk.c:709
> > __sys_bind+0x1e9/0x250 net/socket.c:1656
> > __do_sys_bind net/socket.c:1667 [inline]
> > __se_sys_bind net/socket.c:1665 [inline]
> > __x64_sys_bind+0x6f/0xb0 net/socket.c:1665
> > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
> > entry_SYSCALL_64_after_hwframe+0x44/0xa9
> >
> > Freed by task 6854:
> > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
> > kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
> > kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
> > __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
> > __cache_free mm/slab.c:3418 [inline]
> > kfree+0x103/0x2c0 mm/slab.c:3756
> > kvfree+0x42/0x50 mm/util.c:603
> > xp_destroy net/xdp/xsk_buff_pool.c:44 [inline]
> > xp_destroy+0x45/0x60 net/xdp/xsk_buff_pool.c:38
> > xsk_bind+0xbdd/0xed0 net/xdp/xsk.c:719
> > __sys_bind+0x1e9/0x250 net/socket.c:1656
> > __do_sys_bind net/socket.c:1667 [inline]
> > __se_sys_bind net/socket.c:1665 [inline]
> > __x64_sys_bind+0x6f/0xb0 net/socket.c:1665
> > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
> > entry_SYSCALL_64_after_hwframe+0x44/0xa9
> >
> > The buggy address belongs to the object at ffff8880a6a4d800
> > which belongs to the cache kmalloc-1k of size 1024
> > The buggy address is located 96 bytes inside of
> > 1024-byte region [ffff8880a6a4d800, ffff8880a6a4dc00)
> > The buggy address belongs to the page:
> > page:00000000dd5fc18f refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa6a4d
> > flags: 0xfffe0000000200(slab)
> > raw: 00fffe0000000200 ffffea00029cce48 ffffea00025f2148 ffff8880aa040700
> > raw: 0000000000000000 ffff8880a6a4d000 0000000100000002 0000000000000000
> > page dumped because: kasan: bad access detected
> >
> > Memory state around the buggy address:
> > ffff8880a6a4d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> > ffff8880a6a4d780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> >> ffff8880a6a4d800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ^
> > ffff8880a6a4d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff8880a6a4d900: 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.
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> > syzbot can test patches for this issue, for details see:
> > https://goo.gl/tpsmEJ#testing-patches
> >
>