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

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

[Masami Hiramatsu]

On Thu, 30 May 2024 23:50:32 -0700
syzbot <syzbot+list0820d438c1905c75bc71@syzkaller.appspotmail.com> 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, 10 issues are still open and 35 have been fixed so far.
> 
> Some of the still happening issues:
> 
> Ref Crashes Repro Title
> <1> 705     Yes   WARNING in format_decode (3)
>                   https://syzkaller.appspot.com/bug?extid=e2c932aec5c8a6e1d31c

Could you send this to bpf folks? It seems bpf_trace_printk caused this errror.
(Maybe skipping fmt string check?)

> <2> 26      Yes   INFO: task hung in blk_trace_ioctl (4)
>                   https://syzkaller.appspot.com/bug?extid=ed812ed461471ab17a0c

This looks like debugfs_mutex lock leakage. Need to rerun with lockdep.

> <3> 7       Yes   WARNING in get_probe_ref
>                   https://syzkaller.appspot.com/bug?extid=8672dcb9d10011c0a160

Hm, fail on register_trace_block_rq_insert(). blktrace issue.

> <4> 6       Yes   INFO: task hung in blk_trace_remove (2)
>                   https://syzkaller.appspot.com/bug?extid=2373f6be3e6de4f92562

This looks like debugfs_mutex lock leakage too.

> <5> 5       Yes   general protection fault in bpf_get_attach_cookie_tracing
>                   https://syzkaller.appspot.com/bug?extid=3ab78ff125b7979e45f9

This is also BPF problem.

Thank you,

> 
> ---
> 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.
> 
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> 
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> 
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-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>

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

[Jiri Olsa]

On Sun, Jun 02, 2024 at 12:09:50PM +0900, Masami Hiramatsu wrote:
> On Thu, 30 May 2024 23:50:32 -0700
> syzbot <syzbot+list0820d438c1905c75bc71@syzkaller.appspotmail.com> 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, 10 issues are still open and 35 have been fixed so far.
> > 
> > Some of the still happening issues:
> > 
> > Ref Crashes Repro Title
> > <1> 705     Yes   WARNING in format_decode (3)
> >                   https://syzkaller.appspot.com/bug?extid=e2c932aec5c8a6e1d31c
> 
> Could you send this to bpf folks? It seems bpf_trace_printk caused this errror.
> (Maybe skipping fmt string check?)
> 
> > <2> 26      Yes   INFO: task hung in blk_trace_ioctl (4)
> >                   https://syzkaller.appspot.com/bug?extid=ed812ed461471ab17a0c
> 
> This looks like debugfs_mutex lock leakage. Need to rerun with lockdep.
> 
> > <3> 7       Yes   WARNING in get_probe_ref
> >                   https://syzkaller.appspot.com/bug?extid=8672dcb9d10011c0a160
> 
> Hm, fail on register_trace_block_rq_insert(). blktrace issue.
> 
> > <4> 6       Yes   INFO: task hung in blk_trace_remove (2)
> >                   https://syzkaller.appspot.com/bug?extid=2373f6be3e6de4f92562
> 
> This looks like debugfs_mutex lock leakage too.
> 
> > <5> 5       Yes   general protection fault in bpf_get_attach_cookie_tracing
> >                   https://syzkaller.appspot.com/bug?extid=3ab78ff125b7979e45f9
> 
> This is also BPF problem.

this one seems to be easy to fix, can't reproduce with either the change
below or with instrumenting __bpf_prog_test_run_raw_tp to set current->bpf_ctx
as in __bpf_trace_run

will send a patch

thanks,
jirka


---
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 593efccc2030..fc303c20f402 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1148,6 +1148,8 @@ BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
 {
 	struct bpf_trace_run_ctx *run_ctx;
 
+	if (!current->bpf_ctx)
+		return 0;
 	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
 	return run_ctx->bpf_cookie;
 }

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

[Jiri Olsa]

On Sun, Jun 02, 2024 at 10:52:43PM +0200, Jiri Olsa wrote:
> On Sun, Jun 02, 2024 at 12:09:50PM +0900, Masami Hiramatsu wrote:
> > On Thu, 30 May 2024 23:50:32 -0700
> > syzbot <syzbot+list0820d438c1905c75bc71@syzkaller.appspotmail.com> 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, 10 issues are still open and 35 have been fixed so far.
> > > 
> > > Some of the still happening issues:
> > > 
> > > Ref Crashes Repro Title
> > > <1> 705     Yes   WARNING in format_decode (3)
> > >                   https://syzkaller.appspot.com/bug?extid=e2c932aec5c8a6e1d31c
> > 
> > Could you send this to bpf folks? It seems bpf_trace_printk caused this errror.
> > (Maybe skipping fmt string check?)
> > 
> > > <2> 26      Yes   INFO: task hung in blk_trace_ioctl (4)
> > >                   https://syzkaller.appspot.com/bug?extid=ed812ed461471ab17a0c
> > 
> > This looks like debugfs_mutex lock leakage. Need to rerun with lockdep.
> > 
> > > <3> 7       Yes   WARNING in get_probe_ref
> > >                   https://syzkaller.appspot.com/bug?extid=8672dcb9d10011c0a160
> > 
> > Hm, fail on register_trace_block_rq_insert(). blktrace issue.
> > 
> > > <4> 6       Yes   INFO: task hung in blk_trace_remove (2)
> > >                   https://syzkaller.appspot.com/bug?extid=2373f6be3e6de4f92562
> > 
> > This looks like debugfs_mutex lock leakage too.
> > 
> > > <5> 5       Yes   general protection fault in bpf_get_attach_cookie_tracing
> > >                   https://syzkaller.appspot.com/bug?extid=3ab78ff125b7979e45f9
> > 
> > This is also BPF problem.
> 
> this one seems to be easy to fix, can't reproduce with either the change
> below or with instrumenting __bpf_prog_test_run_raw_tp to set current->bpf_ctx
> as in __bpf_trace_run
> 
> will send a patch
> 
> thanks,
> jirka
> 
> 
> ---
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 593efccc2030..fc303c20f402 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1148,6 +1148,8 @@ BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)

nah sry, sent wrong change, should be in bpf_get_attach_cookie_tracing
will send formal patch

jirka

>  {
>  	struct bpf_trace_run_ctx *run_ctx;
>  
> +	if (!current->bpf_ctx)
> +		return 0;
>  	run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
>  	return run_ctx->bpf_cookie;
>  }