lkml.org 
[lkml]   [2021]   [Dec]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
Subject[syzbot] BUG: unable to handle kernel NULL pointer dereference in folio_mark_dirty
From
Hello,

syzbot found the following issue on:

HEAD commit: 58e1100fdc59 MAINTAINERS: co-maintain random.c
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1362881eb00000
kernel config: https://syzkaller.appspot.com/x/.config?x=e9ea28d2c3c2c389
dashboard link: https://syzkaller.appspot.com/bug?extid=7cd473c2cac13fd2dd72
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2

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: syzbot+7cd473c2cac13fd2dd72@syzkaller.appspotmail.com

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 70764067 P4D 70764067 PUD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 6541 Comm: syz-executor.3 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc900027ff7f8 EFLAGS: 00010246
RAX: 1ffffffff14fef03 RBX: ffffffff8a7f7818 RCX: ffff88801b40d700
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0002790ec0
RBP: dffffc0000000000 R08: ffffffff81b0fa16 R09: fffff940004f21d9
R10: fffff940004f21d9 R11: 0000000000000000 R12: ffff88806c11c7b0
R13: 0000000000000000 R14: 1ffffd40004f21d9 R15: ffffea0002790ec0
FS: 0000555557165400(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000030d85000 CR4: 00000000003526e0
Call Trace:
<TASK>
folio_mark_dirty+0x136/0x270 mm/page-writeback.c:2639
f2fs_update_meta_page+0x4b/0x380 fs/f2fs/segment.c:2485
do_checkpoint fs/f2fs/checkpoint.c:1513 [inline]
f2fs_write_checkpoint+0x31ad/0x5430 fs/f2fs/checkpoint.c:1674
f2fs_issue_checkpoint+0x361/0x4e0
sync_filesystem+0x19c/0x1f0 fs/sync.c:63
generic_shutdown_super+0x6b/0x300 fs/super.c:448
kill_block_super+0x79/0xd0 fs/super.c:1397
kill_f2fs_super+0x2f9/0x3c0 fs/f2fs/super.c:4478
deactivate_locked_super+0xa7/0xf0 fs/super.c:335
cleanup_mnt+0x462/0x510 fs/namespace.c:1137
task_work_run+0x146/0x1c0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x209/0x220 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300
do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f6cfdd59f57
Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffcbddcad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f6cfdd59f57
RDX: 00007fffcbddcbac RSI: 000000000000000a RDI: 00007fffcbddcba0
RBP: 00007fffcbddcba0 R08: 00000000ffffffff R09: 00007fffcbddc970
R10: 0000555557166903 R11: 0000000000000246 R12: 00007f6cfddb2105
R13: 00007fffcbdddc60 R14: 0000555557166810 R15: 00007fffcbdddca0
</TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 08eda5a5e35b48a0 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc900027ff7f8 EFLAGS: 00010246
RAX: 1ffffffff14fef03 RBX: ffffffff8a7f7818 RCX: ffff88801b40d700
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0002790ec0
RBP: dffffc0000000000 R08: ffffffff81b0fa16 R09: fffff940004f21d9
R10: fffff940004f21d9 R11: 0000000000000000 R12: ffff88806c11c7b0
R13: 0000000000000000 R14: 1ffffd40004f21d9 R15: ffffea0002790ec0
FS: 0000555557165400(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000030d85000 CR4: 00000000003526e0


---
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.

\
 
 \ /
  Last update: 2021-12-04 10:56    [W:0.046 / U:8.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site