syzbot


WARNING in ring_buffer_map_get_reader

Status: fixed on 2026/01/07 12:29
Subsystems: trace
[Documentation on labels]
Reported-by: syzbot+92a3745cea5ec6360309@syzkaller.appspotmail.com
Fix commit: aa997d2d2a0b ring-buffer: Do not warn in ring_buffer_map_get_reader() when reader catches up
First crash: 73d, last: 11d
Discussions (2)
Title Replies (including bot) Last reply
[for-linus][PATCH 1/3] ring-buffer: Do not warn in ring_buffer_map_get_reader() when reader catches up 1 (1) 2025/11/07 13:07
[syzbot] [trace?] WARNING in ring_buffer_map_get_reader 0 (1) 2025/11/05 19:56
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in ring_buffer_map_get_reader (2) trace -1 9 7h50m 1d19h 0/29 upstream: reported on 2026/01/12 00:25

Sample crash report:
------------[ cut here ]------------
WARNING: kernel/trace/ring_buffer.c:7361 at ring_buffer_map_get_reader+0x689/0x8d0 kernel/trace/ring_buffer.c:7361, CPU#1: syz.0.2478/17998
Modules linked in:
CPU: 1 UID: 0 PID: 17998 Comm: syz.0.2478 Tainted: G     U  W    L XTNJ syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:ring_buffer_map_get_reader+0x689/0x8d0 kernel/trace/ring_buffer.c:7361
Code: 02 00 00 49 8b 0c 24 8b 74 24 44 4c 89 ea 48 c7 c7 e0 6b 93 8b e8 47 5f d9 ff e9 e6 fe ff ff 4c 8b 64 24 60 e8 08 b4 fb ff 90 <0f> 0b 90 e8 ff b3 fb ff 48 89 df 31 db e8 d5 f9 fd ff 48 8b 74 24
RSP: 0018:ffffc9000475fdb0 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffff88813ff68800 RCX: ffffffff81c2015c
RDX: ffff8880301e8000 RSI: ffffffff81c2b6e8 RDI: 0000000000000007
RBP: dffffc0000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88813ff688b0 R12: ffff88813ff68990
R13: 0000000000000000 R14: ffff88813ff688a8 R15: ffff88813ff688b0
FS:  00007fc86648d6c0(0000) GS:ffff8881249fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001c704000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 tracing_buffers_ioctl+0x2ab/0x360 kernel/trace/trace.c:8932
 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:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc86558f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc86648d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc8657e6090 RCX: 00007fc86558f7c9
RDX: 0000000000000000 RSI: 0000000000005220 RDI: 0000000000000005
RBP: 00007fc865613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc8657e6128 R14: 00007fc8657e6090 R15: 00007ffecdbdf3c8
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/02 09:51 upstream b69053dd3ffb d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in ring_buffer_map_get_reader
2026/01/02 03:06 upstream b69053dd3ffb d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in ring_buffer_map_get_reader
2026/01/01 07:54 upstream 349bd28a86f2 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in ring_buffer_map_get_reader
2026/01/01 06:56 upstream 349bd28a86f2 d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in ring_buffer_map_get_reader
2025/11/01 19:54 upstream 691d401c7e0e 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in ring_buffer_map_get_reader
* Struck through repros no longer work on HEAD.