From: syzbot <syzbot+4faa3fd832279bd35a81@syzkaller.appspotmail.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com, tj@kernel.org
Subject: [syzbot] [kernfs?] BUG: unable to handle kernel paging request in kernfs_remove_by_name_ns
Date: Mon, 04 Aug 2025 01:38:27 -0700 [thread overview]
Message-ID: <68907183.050a0220.7f033.0006.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 5f33ebd2018c Merge tag 'drm-fixes-2025-07-26' of https://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10908034580000
kernel config: https://syzkaller.appspot.com/x/.config?x=186272c644ef9aa3
dashboard link: https://syzkaller.appspot.com/bug?extid=4faa3fd832279bd35a81
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-5f33ebd2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/582eb02b72dc/vmlinux-5f33ebd2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ce6a4956089e/bzImage-5f33ebd2.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4faa3fd832279bd35a81@syzkaller.appspotmail.com
comedi comedi3: c6xdigio: I/O port conflict (0xcf7,3)
BUG: unable to handle page fault for address: ffffffff9ee57158
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD e387067 P4D e387067 PUD e388063 PMD 0
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 8309 Comm: syz.5.701 Not tainted 6.16.0-rc7-syzkaller-00120-g5f33ebd2018c #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:227 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:__lock_acquire+0x46e/0x1c90 kernel/locking/lockdep.c:5210
Code: 78 5d 3f 03 0f b6 54 24 28 85 c0 74 10 44 8b 1d 48 0b 11 0f 45 85 db 0f 84 db 05 00 00 90 31 c9 e9 8a fe ff ff 48 63 44 24 10 <48> 0f a3 05 0a 5c 3e 14 0f 82 7b ff ff ff 90 e8 3e 5d 3f 03 85 c0
RSP: 0018:ffffc9000336f7a0 EFLAGS: 00010046
RAX: 00000000487561e4 RBX: 0000000000000003 RCX: 0000000000000008
RDX: 0000000000000000 RSI: ffff888029e02fa8 RDI: ffff888029e02440
RBP: ffff888029e02440 R08: ffffffff95d842a8 R09: 0000000000000001
R10: 0000000000000010 R11: 0000000000000005 R12: ffff888029e02f30
R13: ffff888029e02fa8 R14: 0000000000000003 R15: 0000000000000003
FS: 00007f603693a6c0(0000) GS:ffff8880d6820000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff9ee57158 CR3: 000000006039a000 CR4: 0000000000352ef0
Call Trace:
<TASK>
lock_acquire kernel/locking/lockdep.c:5871 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
down_write+0x92/0x200 kernel/locking/rwsem.c:1577
kernfs_remove_by_name_ns+0x3d/0x110 fs/kernfs/dir.c:1712
sysfs_remove_file include/linux/sysfs.h:777 [inline]
driver_remove_file drivers/base/driver.c:201 [inline]
driver_remove_file+0x4a/0x60 drivers/base/driver.c:197
remove_bind_files drivers/base/bus.c:605 [inline]
bus_remove_driver+0x224/0x2c0 drivers/base/bus.c:743
driver_unregister+0x76/0xb0 drivers/base/driver.c:277
comedi_device_detach+0x13d/0x9e0 drivers/comedi/drivers.c:207
comedi_device_attach+0x43d/0x900 drivers/comedi/drivers.c:1003
do_devconfig_ioctl+0x1a7/0x580 drivers/comedi/comedi_fops.c:855
comedi_unlocked_ioctl+0x165d/0x2f00 drivers/comedi/comedi_fops.c:2156
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6035b8e9a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f603693a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f6035db5fa0 RCX: 00007f6035b8e9a9
RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000003
RBP: 00007f6035c10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6035db5fa0 R15: 00007ffe08e77888
</TASK>
Modules linked in:
CR2: ffffffff9ee57158
---[ end trace 0000000000000000 ]---
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:227 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:__lock_acquire+0x46e/0x1c90 kernel/locking/lockdep.c:5210
Code: 78 5d 3f 03 0f b6 54 24 28 85 c0 74 10 44 8b 1d 48 0b 11 0f 45 85 db 0f 84 db 05 00 00 90 31 c9 e9 8a fe ff ff 48 63 44 24 10 <48> 0f a3 05 0a 5c 3e 14 0f 82 7b ff ff ff 90 e8 3e 5d 3f 03 85 c0
RSP: 0018:ffffc9000336f7a0 EFLAGS: 00010046
RAX: 00000000487561e4 RBX: 0000000000000003 RCX: 0000000000000008
RDX: 0000000000000000 RSI: ffff888029e02fa8 RDI: ffff888029e02440
RBP: ffff888029e02440 R08: ffffffff95d842a8 R09: 0000000000000001
R10: 0000000000000010 R11: 0000000000000005 R12: ffff888029e02f30
R13: ffff888029e02fa8 R14: 0000000000000003 R15: 0000000000000003
FS: 00007f603693a6c0(0000) GS:ffff8880d6820000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff9ee57158 CR3: 000000006039a000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess), 3 bytes skipped:
0: 03 0f add (%rdi),%ecx
2: b6 54 mov $0x54,%dh
4: 24 28 and $0x28,%al
6: 85 c0 test %eax,%eax
8: 74 10 je 0x1a
a: 44 8b 1d 48 0b 11 0f mov 0xf110b48(%rip),%r11d # 0xf110b59
11: 45 85 db test %r11d,%r11d
14: 0f 84 db 05 00 00 je 0x5f5
1a: 90 nop
1b: 31 c9 xor %ecx,%ecx
1d: e9 8a fe ff ff jmp 0xfffffeac
22: 48 63 44 24 10 movslq 0x10(%rsp),%rax
* 27: 48 0f a3 05 0a 5c 3e bt %rax,0x143e5c0a(%rip) # 0x143e5c39 <-- trapping instruction
2e: 14
2f: 0f 82 7b ff ff ff jb 0xffffffb0
35: 90 nop
36: e8 3e 5d 3f 03 call 0x33f5d79
3b: 85 c0 test %eax,%eax
---
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reply other threads:[~2025-08-04 8:38 UTC|newest]
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