* [syzbot] [bcachefs?] BUG: unable to handle kernel paging request in pipe_write
@ 2025-03-07 7:50 syzbot
2025-03-07 11:23 ` Kent Overstreet
0 siblings, 1 reply; 2+ messages in thread
From: syzbot @ 2025-03-07 7:50 UTC (permalink / raw)
To: brauner, jack, kent.overstreet, linux-bcachefs, linux-fsdevel,
linux-kernel, syzkaller-bugs, viro
Hello,
syzbot found the following issue on:
HEAD commit: 848e07631744 Merge tag 'hid-for-linus-2025030501' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=173c4a64580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2040405600e83619
dashboard link: https://syzkaller.appspot.com/bug?extid=46cddce16efb51810fff
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10c7fda8580000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-848e0763.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c46426c0526b/vmlinux-848e0763.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d575feb1a7df/bzImage-848e0763.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/50b3934b613c/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+46cddce16efb51810fff@syzkaller.appspotmail.com
BUG: unable to handle page fault for address: ffff887fabfbcf80
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5336 Comm: syz-executor Not tainted 6.14.0-rc5-syzkaller-00039-g848e07631744 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__percpu_down_read_trylock kernel/locking/percpu-rwsem.c:50 [inline]
RIP: 0010:__percpu_down_read+0x40/0x130 kernel/locking/percpu-rwsem.c:169
Code: 49 bd 00 00 00 00 00 fc ff df 4c 8d 77 68 4c 89 f5 48 c1 ed 03 42 80 7c 2d 00 00 74 08 4c 89 f7 e8 35 7e 1e f6 49 8b 44 24 68 <65> ff 00 f0 83 44 24 fc 00 49 8d 9c 24 c8 00 00 00 48 89 df be 04
RSP: 0018:ffffc9000d1c7aa0 EFLAGS: 00010246
RAX: ffffffff8c3bcf80 RBX: 000000008e29c24b RCX: ffff8880001fc880
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8ecc2fd8
RBP: 1ffffffff1d98608 R08: ffffffff823d3401 R09: 1ffffffff2079e8e
R10: dffffc0000000000 R11: fffffbfff2079e8f R12: ffffffff8ecc2fd8
R13: dffffc0000000000 R14: ffffffff8ecc3040 R15: ffffffff8ecc2fd8
FS: 0000555594365500(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff887fabfbcf80 CR3: 000000004349a000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
percpu_down_read_trylock include/linux/percpu-rwsem.h:84 [inline]
__sb_start_write_trylock include/linux/fs.h:1790 [inline]
sb_start_write_trylock include/linux/fs.h:1926 [inline]
pipe_write+0x16db/0x1950 fs/pipe.c:605
new_sync_write fs/read_write.c:586 [inline]
vfs_write+0xacf/0xd10 fs/read_write.c:679
ksys_write+0x18f/0x2b0 fs/read_write.c:731
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc094d8bbe0
Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 61 19 1f 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007ffe88624b48 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555594379d50 RCX: 00007fc094d8bbe0
RDX: 0000000000000030 RSI: 00007ffe88624b80 RDI: 000000000000000b
RBP: 0000555594378f20 R08: 0000000005a61143 R09: 7fffffffffffffff
R10: 00007fc095b50038 R11: 0000000000000202 R12: 0000000000000001
R13: 0000000000000000 R14: 00007ffe88624b60 R15: 0000000000000000
</TASK>
Modules linked in:
CR2: ffff887fabfbcf80
---[ end trace 0000000000000000 ]---
RIP: 0010:__percpu_down_read_trylock kernel/locking/percpu-rwsem.c:50 [inline]
RIP: 0010:__percpu_down_read+0x40/0x130 kernel/locking/percpu-rwsem.c:169
Code: 49 bd 00 00 00 00 00 fc ff df 4c 8d 77 68 4c 89 f5 48 c1 ed 03 42 80 7c 2d 00 00 74 08 4c 89 f7 e8 35 7e 1e f6 49 8b 44 24 68 <65> ff 00 f0 83 44 24 fc 00 49 8d 9c 24 c8 00 00 00 48 89 df be 04
RSP: 0018:ffffc9000d1c7aa0 EFLAGS: 00010246
RAX: ffffffff8c3bcf80 RBX: 000000008e29c24b RCX: ffff8880001fc880
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8ecc2fd8
RBP: 1ffffffff1d98608 R08: ffffffff823d3401 R09: 1ffffffff2079e8e
R10: dffffc0000000000 R11: fffffbfff2079e8f R12: ffffffff8ecc2fd8
R13: dffffc0000000000 R14: ffffffff8ecc3040 R15: ffffffff8ecc2fd8
FS: 0000555594365500(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff887fabfbcf80 CR3: 000000004349a000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13
7: fc ff df
a: 4c 8d 77 68 lea 0x68(%rdi),%r14
e: 4c 89 f5 mov %r14,%rbp
11: 48 c1 ed 03 shr $0x3,%rbp
15: 42 80 7c 2d 00 00 cmpb $0x0,0x0(%rbp,%r13,1)
1b: 74 08 je 0x25
1d: 4c 89 f7 mov %r14,%rdi
20: e8 35 7e 1e f6 call 0xf61e7e5a
25: 49 8b 44 24 68 mov 0x68(%r12),%rax
* 2a: 65 ff 00 incl %gs:(%rax) <-- trapping instruction
2d: f0 83 44 24 fc 00 lock addl $0x0,-0x4(%rsp)
33: 49 8d 9c 24 c8 00 00 lea 0xc8(%r12),%rbx
3a: 00
3b: 48 89 df mov %rbx,%rdi
3e: be .byte 0xbe
3f: 04 .byte 0x4
---
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 syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [syzbot] [bcachefs?] BUG: unable to handle kernel paging request in pipe_write
2025-03-07 7:50 [syzbot] [bcachefs?] BUG: unable to handle kernel paging request in pipe_write syzbot
@ 2025-03-07 11:23 ` Kent Overstreet
0 siblings, 0 replies; 2+ messages in thread
From: Kent Overstreet @ 2025-03-07 11:23 UTC (permalink / raw)
To: syzbot
Cc: brauner, jack, linux-bcachefs, linux-fsdevel, linux-kernel,
syzkaller-bugs, viro
So this is after a bcachefs failure to mount - filesystem bringup error
path - which implies we've got a memory stomper that kasan isn't able to
catch.
There's a couple that fit that pattern, and I think percpu allocations
were involved in all of them...
On Thu, Mar 06, 2025 at 11:50:20PM -0800, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 848e07631744 Merge tag 'hid-for-linus-2025030501' of git:/..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=173c4a64580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=2040405600e83619
> dashboard link: https://syzkaller.appspot.com/bug?extid=46cddce16efb51810fff
> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10c7fda8580000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-848e0763.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/c46426c0526b/vmlinux-848e0763.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/d575feb1a7df/bzImage-848e0763.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/50b3934b613c/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+46cddce16efb51810fff@syzkaller.appspotmail.com
>
> BUG: unable to handle page fault for address: ffff887fabfbcf80
> #PF: supervisor write access in kernel mode
> #PF: error_code(0x0002) - not-present page
> PGD 0 P4D 0
> Oops: Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI
> CPU: 0 UID: 0 PID: 5336 Comm: syz-executor Not tainted 6.14.0-rc5-syzkaller-00039-g848e07631744 #0
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
> RIP: 0010:__percpu_down_read_trylock kernel/locking/percpu-rwsem.c:50 [inline]
> RIP: 0010:__percpu_down_read+0x40/0x130 kernel/locking/percpu-rwsem.c:169
> Code: 49 bd 00 00 00 00 00 fc ff df 4c 8d 77 68 4c 89 f5 48 c1 ed 03 42 80 7c 2d 00 00 74 08 4c 89 f7 e8 35 7e 1e f6 49 8b 44 24 68 <65> ff 00 f0 83 44 24 fc 00 49 8d 9c 24 c8 00 00 00 48 89 df be 04
> RSP: 0018:ffffc9000d1c7aa0 EFLAGS: 00010246
> RAX: ffffffff8c3bcf80 RBX: 000000008e29c24b RCX: ffff8880001fc880
> RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8ecc2fd8
> RBP: 1ffffffff1d98608 R08: ffffffff823d3401 R09: 1ffffffff2079e8e
> R10: dffffc0000000000 R11: fffffbfff2079e8f R12: ffffffff8ecc2fd8
> R13: dffffc0000000000 R14: ffffffff8ecc3040 R15: ffffffff8ecc2fd8
> FS: 0000555594365500(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffff887fabfbcf80 CR3: 000000004349a000 CR4: 0000000000352ef0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> percpu_down_read_trylock include/linux/percpu-rwsem.h:84 [inline]
> __sb_start_write_trylock include/linux/fs.h:1790 [inline]
> sb_start_write_trylock include/linux/fs.h:1926 [inline]
> pipe_write+0x16db/0x1950 fs/pipe.c:605
> new_sync_write fs/read_write.c:586 [inline]
> vfs_write+0xacf/0xd10 fs/read_write.c:679
> ksys_write+0x18f/0x2b0 fs/read_write.c:731
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7fc094d8bbe0
> Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 61 19 1f 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
> RSP: 002b:00007ffe88624b48 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 0000555594379d50 RCX: 00007fc094d8bbe0
> RDX: 0000000000000030 RSI: 00007ffe88624b80 RDI: 000000000000000b
> RBP: 0000555594378f20 R08: 0000000005a61143 R09: 7fffffffffffffff
> R10: 00007fc095b50038 R11: 0000000000000202 R12: 0000000000000001
> R13: 0000000000000000 R14: 00007ffe88624b60 R15: 0000000000000000
> </TASK>
> Modules linked in:
> CR2: ffff887fabfbcf80
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:__percpu_down_read_trylock kernel/locking/percpu-rwsem.c:50 [inline]
> RIP: 0010:__percpu_down_read+0x40/0x130 kernel/locking/percpu-rwsem.c:169
> Code: 49 bd 00 00 00 00 00 fc ff df 4c 8d 77 68 4c 89 f5 48 c1 ed 03 42 80 7c 2d 00 00 74 08 4c 89 f7 e8 35 7e 1e f6 49 8b 44 24 68 <65> ff 00 f0 83 44 24 fc 00 49 8d 9c 24 c8 00 00 00 48 89 df be 04
> RSP: 0018:ffffc9000d1c7aa0 EFLAGS: 00010246
> RAX: ffffffff8c3bcf80 RBX: 000000008e29c24b RCX: ffff8880001fc880
> RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8ecc2fd8
> RBP: 1ffffffff1d98608 R08: ffffffff823d3401 R09: 1ffffffff2079e8e
> R10: dffffc0000000000 R11: fffffbfff2079e8f R12: ffffffff8ecc2fd8
> R13: dffffc0000000000 R14: ffffffff8ecc3040 R15: ffffffff8ecc2fd8
> FS: 0000555594365500(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffff887fabfbcf80 CR3: 000000004349a000 CR4: 0000000000352ef0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> ----------------
> Code disassembly (best guess):
> 0: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13
> 7: fc ff df
> a: 4c 8d 77 68 lea 0x68(%rdi),%r14
> e: 4c 89 f5 mov %r14,%rbp
> 11: 48 c1 ed 03 shr $0x3,%rbp
> 15: 42 80 7c 2d 00 00 cmpb $0x0,0x0(%rbp,%r13,1)
> 1b: 74 08 je 0x25
> 1d: 4c 89 f7 mov %r14,%rdi
> 20: e8 35 7e 1e f6 call 0xf61e7e5a
> 25: 49 8b 44 24 68 mov 0x68(%r12),%rax
> * 2a: 65 ff 00 incl %gs:(%rax) <-- trapping instruction
> 2d: f0 83 44 24 fc 00 lock addl $0x0,-0x4(%rsp)
> 33: 49 8d 9c 24 c8 00 00 lea 0xc8(%r12),%rbx
> 3a: 00
> 3b: 48 89 df mov %rbx,%rdi
> 3e: be .byte 0xbe
> 3f: 04 .byte 0x4
>
>
> ---
> 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 syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2025-03-07 11:23 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
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2025-03-07 7:50 [syzbot] [bcachefs?] BUG: unable to handle kernel paging request in pipe_write syzbot
2025-03-07 11:23 ` Kent Overstreet
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