WARNING in uprobe_unregister

Status: upstream: reported C repro on 2025/10/01 18:27
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+cbe3f27f022f79f14611@syzkaller.appspotmail.com
First crash: 328d, last: 1d19h
Bug presence (2)
Date Name Commit Repro Result
2025/10/06 linux-6.6.y (ToT) f34f16e5c632 syz [report] WARNING in uprobe_unregister
2025/10/06 upstream (ToT) fd94619c4336 syz Didn't crash
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2025/11/11 12:14 1h20m fix candidate upstream OK (0) job log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8217 at kernel/events/uprobes.c:1123 uprobe_unregister+0x63/0x70 kernel/events/uprobes.c:1123
Modules linked in:
CPU: 0 PID: 8217 Comm: syz.2.1092 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:uprobe_unregister+0x63/0x70 kernel/events/uprobes.c:1123
Code: e8 22 09 e5 08 4c 89 f7 48 89 de e8 a7 01 00 00 4c 89 ff e8 bf 6a b4 ff 4c 89 f7 5b 41 5e 41 5f e9 82 03 00 00 e8 ed e9 d3 ff <0f> 0b 5b 41 5e 41 5f c3 0f 1f 44 00 00 55 41 57 41 56 41 55 41 54
RSP: 0018:ffffc9000d98fca8 EFLAGS: 00010293
RAX: ffffffff81b38883 RBX: ffff88807d671da0 RCX: ffff888028f45a00
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: ffff88805dfe8f18 R08: ffffffff8d1d4343 R09: 1ffffffff1a3a868
R10: dffffc0000000000 R11: fffffbfff1a3a869 R12: ffffffff8b01e120
R13: ffff88807d671da0 R14: 0000000000000000 R15: ffff88805dfe8f18
FS:  000055558ff9b500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b6d80c000 CR3: 000000005b7a0000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 bpf_uprobe_unregister kernel/trace/bpf_trace.c:3082 [inline]
 bpf_uprobe_multi_link_release+0x14f/0x310 kernel/trace/bpf_trace.c:3092
 bpf_link_free+0x123/0x300 kernel/bpf/syscall.c:2921
 bpf_link_put_direct kernel/bpf/syscall.c:2961 [inline]
 bpf_link_release+0x6e/0x80 kernel/bpf/syscall.c:2968
 __fput+0x221/0x940 fs/file_table.c:418
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fef1ff9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe416f94f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fef20227da0 RCX: 00007fef1ff9e0d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fef20227da0 R08: 00007fef20226038 R09: 0000000000000000
R10: 000000000003fd84 R11: 0000000000000246 R12: 0000000000028cb8
R13: 00007fef2022609c R14: 0000000000028a20 R15: 00007fef20226090
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/24 00:04 linux-6.6.y dc6160265ffc 1e72964b .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan WARNING in uprobe_unregister
2025/10/03 13:07 linux-6.6.y f34f16e5c632 49379ee0 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan WARNING in uprobe_unregister
2026/08/23 19:23 linux-6.6.y dc6160265ffc 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in uprobe_unregister
2026/07/31 06:10 linux-6.6.y a1153c0deb44 aaffb173 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in uprobe_unregister
2025/10/01 18:27 linux-6.6.y 147338df3487 a1859138 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in uprobe_unregister
* Struck through repros no longer work on HEAD.