Re: WARNING in uprobe_unregister

[Jiri Olsa <olsajiri@gmail.com>]

On Mon, Aug 05, 2024 at 09:50:45AM +0800, Ubisectech Sirius wrote:
> 
> 
> Hello.
> We are Ubisectech Sirius Team, the vulnerability lab of China ValiantSec. Recently, our team has discovered a issue in Linux kernel 6.8. Attached to the email were a PoC file of the issue.
> 
> Stack dump:
> 
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 14015 at kernel/events/uprobes.c:1107 uprobe_unregister+0x66/0x80 kernel/events/uprobes.c:1107
> Modules linked in:
> CPU: 1 PID: 14015 Comm: syz.0.291 Not tainted 6.8.0 #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
> RIP: 0010:uprobe_unregister+0x66/0x80 kernel/events/uprobes.c:1107
> Code: 89 ee 48 89 ef e8 3a fd ff ff 4c 89 e7 e8 72 8b b1 ff 48 89 ef e8 ca aa ff ff 5d 41 5c 41 5d e9 f0 29 d3 ff e8 eb 29 d3 ff 90 <0f> 0b 90 5d 41 5c 41 5d e9 dd 29 d3 ff 66 66 2e 0f 1f 84 00 00 00
> RSP: 0018:ffffc90001e27d18 EFLAGS: 00010293
> RAX: 0000000000000000 RBX: ffff888064695ac8 RCX: 0000000000000000
> RDX: ffff888043b8c980 RSI: ffffffff81b782c5 RDI: 0000000000000001
> RBP: ffff88805e3f5040 R08: 0000000000000000 R09: fffffbfff1a95cf8
> R10: ffffffff8d4ae7c3 R11: 0000000000000000 R12: 0000000000000000
> R13: ffff888064695aa0 R14: 0000000000000000 R15: ffff888064695aa0
> FS:  000055555744b500(0000) GS:ffff88807ec00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000110c394aab CR3: 0000000064b02000 CR4: 0000000000750ef0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> PKRU: 55555554
> Call Trace:
>  <TASK>
>  bpf_uprobe_unregister+0xf7/0x1c0 kernel/trace/bpf_trace.c:3134
>  bpf_link_free+0xe8/0x1b0 kernel/bpf/syscall.c:2904
>  bpf_link_put_direct kernel/bpf/syscall.c:2935 [inline]
>  bpf_link_release+0x62/0x80 kernel/bpf/syscall.c:2942
>  __fput+0x282/0xbc0 fs/file_table.c:376
>  task_work_run+0x16a/0x260 kernel/task_work.c:180
>  resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
>  exit_to_user_mode_loop kernel/entry/common.c:108 [inline]
>  exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
>  __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline]
>  syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:212
>  do_syscall_64+0xe5/0x270 arch/x86/entry/common.c:89
>  entry_SYSCALL_64_after_hwframe+0x6f/0x77
> RIP: 0033:0x7fbb25596e2d
> Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffe3696a318 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
> RAX: 0000000000000000 RBX: 00007fbb25737a80 RCX: 00007fbb25596e2d
> RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
> RBP: 00007fbb25737a80 R08: 0000001b33420214 R09: 0000000000000000
> R10: 0000001b33420210 R11: 0000000000000246 R12: 000000000004ba6b
> R13: 00007ffe3696a3f0 R14: 00007fbb25736064 R15: 00007fbb25737a80
>  </TASK>
> 
> Thank you for taking the time to read this email and we look forward to working with you further.

hi,
thanks for the report

so far I can't hit it with the reproducer, could share your .config?

do you see it on latest bpf-next/master?

thanks,
jirka