WARNING in ring_buffer_map_get_reader (3)

Status: upstream: reported on 2026/09/06 20:15
Subsystems: trace
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+de3d7f9bcc9212f3fae1@syzkaller.appspotmail.com
First crash: 4d01h, last: 4d01h
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
7616afee assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING in ring_buffer_map_get_reader (3) 2026/09/04 05:12 2026/09/04 05:12 2026/09/04 05:38 801f0966
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [trace?] WARNING in ring_buffer_map_get_reader (3) 0 (1) 2026/09/06 20:15
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in ring_buffer_map_get_reader (2) prio:low trace -1 49 146d 237d 0/29 auto-obsoleted due to no activity on 2026/06/22 15:18
upstream WARNING in ring_buffer_map_get_reader trace -1 5 247d 305d 29/29 fixed on 2026/01/07 12:29

Sample crash report:
Cannot find set identified by id 0 to match
------------[ cut here ]------------
!reader
WARNING: kernel/trace/ring_buffer.c:7927 at ring_buffer_map_get_reader+0x5f3/0x930 kernel/trace/ring_buffer.c:7927, CPU#0: syz.2.1764/13608
Modules linked in:
CPU: 0 UID: 0 PID: 13608 Comm: syz.2.1764 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:ring_buffer_map_get_reader+0x5f3/0x930 kernel/trace/ring_buffer.c:7927
Code: ff 48 89 df e8 2e 21 fe ff 48 89 c5 e8 46 8b fb ff 48 85 ed 0f 85 9f fc ff ff 4c 8b 74 24 58 4c 8b 7c 24 60 e8 2e 8b fb ff 90 <0f> 0b 90 e8 25 8b fb ff 49 8d bf d0 01 00 00 48 b8 00 00 00 00 00
RSP: 0018:ffffc90006b57d98 EFLAGS: 00010087
RAX: 000000000000086c RBX: ffff88801c0e5000 RCX: ffffc90024800000
RDX: 0000000000080000 RSI: ffffffff821064e2 RDI: ffff888027852580
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88801c0e50b0 R12: ffff88801c0e50b8
R13: dffffc0000000000 R14: ffff88801c0e5198 R15: ffff88801c0ab800
FS:  00007fa41bfdb6c0(0000) GS:ffff8880d5b61000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f60453c8ff8 CR3: 0000000035d0b000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 tracing_buffers_ioctl+0x2e6/0x3d0 kernel/trace/trace.c:7392
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa41b19e159
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:00007fa41bfdb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa41b425fa0 RCX: 00007fa41b19e159
RDX: 0000000000000000 RSI: 0000000000005220 RDI: 0000000000000007
RBP: 00007fa41b235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa41b426038 R14: 00007fa41b425fa0 R15: 00007ffd22388a08
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/02 20:04 upstream 89a312991dc6 74e93e68 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in ring_buffer_map_get_reader
* Struck through repros no longer work on HEAD.