Re: [syzbot] Monthly trace report (Sep 2024)

[Google]

On Mon, 09 Sep 2024 01:12:20 -0700
syzbot <syzbot+list692d096cfc0c03673c30@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

> Hello trace maintainers/developers,
> 
> This is a 31-day syzbot report for the trace subsystem.
> All related reports/information can be found at:
> https://syzkaller.appspot.com/upstream/s/trace
> 
> During the period, 1 new issues were detected and 0 were fixed.
> In total, 8 issues are still open and 37 have been fixed so far.
> 
> Some of the still happening issues:
> 
> Ref Crashes Repro Title
> <1> 2278    Yes   possible deadlock in console_flush_all (3)
>                   https://syzkaller.appspot.com/bug?extid=18cfb7f63482af8641df

This is artifically injected circuler lock dependency about the combination
of eBPF + fault injection.

 - BPF test program traces sched_switch event. (under rq->lock)
 - fault inject injects a fault in BPF's strncpy_from_user.
 - this fault printk dump to the console.(to lock console_owner)

To avoid this issue, use another event to test fault injection.

> <2> 1023    Yes   WARNING in format_decode (3)
>                   https://syzkaller.appspot.com/bug?extid=e2c932aec5c8a6e1d31c

This seems also be caused by bpf test program.

> <3> 31      Yes   INFO: task hung in blk_trace_ioctl (4)
>                   https://syzkaller.appspot.com/bug?extid=ed812ed461471ab17a0c

This is a bug in blk_trace.

> <4> 15      Yes   WARNING in bpf_get_stack_raw_tp
>                   https://syzkaller.appspot.com/bug?extid=ce35de20ed6652f60652

This may be a bpf issue.

> <5> 11      Yes   WARNING in get_probe_ref
>                   https://syzkaller.appspot.com/bug?extid=8672dcb9d10011c0a160

This is a bug in blk_trace.

It seems blk_trace does not check input parameters of ioctl correctly.

Thank you,

> 
> ---
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-- 
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>