syzbot


kernel BUG in mod_timer

Status: upstream: reported C repro on 2022/11/01 03:13
Reported-by: syzbot+db882eff0b24c7941918@syzkaller.appspotmail.com
First crash: 599d, last: 488d
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2023/02/20 06:42 24m bisect fix linux-4.14.y job log (0) log
2023/01/21 05:46 24m bisect fix linux-4.14.y job log (0) log

Sample crash report:
NILFS (loop5): mounting fs with errors
NILFS (loop3): mounting fs with errors
NILFS (loop5): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
NILFS (loop3): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
------------[ cut here ]------------
kernel BUG at kernel/time/timer.c:939!
Remounting filesystem read-only
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 8031 Comm: syz-executor706 Not tainted 4.14.296-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
task: ffff8880b2908640 task.stack: ffff8880b32a8000
RIP: 0010:__mod_timer kernel/time/timer.c:939 [inline]
RIP: 0010:mod_timer+0x7fd/0xf70 kernel/time/timer.c:1070
RSP: 0018:ffff8880b32afb48 EFLAGS: 00010297
RAX: ffff8880b2908640 RBX: 00000000ffff99e6 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 00000000ffff99e6 RDI: ffff8880b1928bf0
RBP: ffff8880b1928bd8 R08: ffff8880b1928ac0 R09: 000000000004058d
R10: ffff8880b2908f68 R11: ffff8880b2908640 R12: dffffc0000000000
R13: 1ffff11016655f71 R14: ffff8880b1928940 R15: ffff8880b32afc8a
FS:  00007f450d3d4700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555bd8628 CR3: 00000000a04a7000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
NILFS (loop4): error -4 creating segctord thread
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
NILFS (loop2): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
 nilfs_segctor_start_timer fs/nilfs2/segment.c:2139 [inline]
 nilfs_transaction_commit+0x6b4/0xae0 fs/nilfs2/segment.c:288
 nilfs_evict_inode+0x2be/0x3a0 fs/nilfs2/inode.c:967
NILFS (loop2): mounting fs with errors
 evict+0x2c8/0x700 fs/inode.c:554
 iput_final fs/inode.c:1523 [inline]
 iput+0x458/0x7e0 fs/inode.c:1550
 dentry_unlink_inode+0x25c/0x310 fs/dcache.c:387
 d_delete+0x1c5/0x280 fs/dcache.c:2417
 vfs_rmdir.part.0+0x260/0x390 fs/namei.c:3922
 vfs_rmdir fs/namei.c:3895 [inline]
 do_rmdir+0x334/0x3c0 fs/namei.c:3970
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f450d44a199
RSP: 002b:00007f450d3d42f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007f450d4d14b0 RCX: 00007f450d44a199
RDX: 00007f450d3d4700 RSI: d1cff92d779b1a2f RDI: 0000000020000040
RBP: 00007f450d49c730 R08: 00007f450d3d4700 R09: 0000000000000000
R10: 00007f450d3d4700 R11: 0000000000000246 R12: 00007f450d49c308
R13: 00007f450d49c0c8 R14: 0030656c69662f2e R15: 00007f450d4d14b8
Code: ff df 48 c1 ea 03 80 3c 02 00 0f 85 66 06 00 00 48 89 5d 10 4c 89 64 24 10 c7 44 24 08 01 00 00 00 e9 db fc ff ff e8 73 ac 0c 00 <0f> 0b e8 6c ac 0c 00 8b 5c 24 0c 48 b8 00 00 00 00 00 fc ff df 
RIP: __mod_timer kernel/time/timer.c:939 [inline] RSP: ffff8880b32afb48
RIP: mod_timer+0x7fd/0xf70 kernel/time/timer.c:1070 RSP: ffff8880b32afb48
---[ end trace df24e578cdcca7e1 ]---

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/11/01 14:12 linux-4.14.y 41f36d7859a7 a1d8560a .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 kernel BUG in mod_timer
2022/11/01 06:04 linux-4.14.y 41f36d7859a7 a1d8560a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 kernel BUG in mod_timer
2022/11/01 03:13 linux-4.14.y 41f36d7859a7 a1d8560a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 kernel BUG in mod_timer
* Struck through repros no longer work on HEAD.