syzbot


WARNING: refcount bug in call_timer_fn

Status: upstream: reported on 2024/03/01 18:08
Reported-by: syzbot+078fb36c78e055e7f49c@syzkaller.appspotmail.com
First crash: 63d, last: 63d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING: refcount bug in call_timer_fn net 1 880d 880d 0/26 closed as invalid on 2022/01/07 18:56

Sample crash report:
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 21 at lib/refcount.c:28 refcount_warn_saturate+0x14e/0x1a0 lib/refcount.c:28
Modules linked in:
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 6.1.80-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:refcount_warn_saturate+0x14e/0x1a0 lib/refcount.c:28
Code: 0a 01 48 c7 c7 c0 d4 3c 8b e8 5e 9e 1a fd 0f 0b eb 8d e8 65 a1 52 fd c6 05 a6 4d 27 0a 01 48 c7 c7 20 d5 3c 8b e8 42 9e 1a fd <0f> 0b e9 6e ff ff ff e8 46 a1 52 fd c6 05 88 4d 27 0a 01 48 c7 c7
RSP: 0018:ffffc900001b7a08 EFLAGS: 00010246
RAX: cd91b964d3de7b00 RBX: 0000000000000003 RCX: ffff888012751dc0
RDX: 0000000080000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffffffff81527e8e R09: ffffed1017324f1c
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000036f48 R14: 0000000000000001 R15: 0000000000000100
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6f2a261fe8 CR3: 000000000ce8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1790
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571
 run_ksoftirqd+0xc1/0x120 kernel/softirq.c:934
 smpboot_thread_fn+0x52c/0xa30 kernel/smpboot.c:164
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/01 18:07 linux-6.1.y a3eb3a74aa8c 83acf9e0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: refcount bug in call_timer_fn
* Struck through repros no longer work on HEAD.