syzbot


WARNING in est_timer

Status: upstream: reported C repro on 2025/08/26 18:03
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+72db9ee39db57c3fecc5@syzkaller.appspotmail.com
Fix commit: net_sched: gen_estimator: fix est_timer() vs CONFIG_PREEMPT_RT=y
Patched on: [ci-upstream-net-this-kasan-gce], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 9d09h, last: 47m
Cause bisection: failed (error log, bisect log)
  
Discussions (3)
Title Replies (including bot) Last reply
[syzbot] [net?] WARNING in est_timer 1 (4) 2025/08/30 03:30
[PATCH v2 net] net_sched: gen_estimator: fix est_timer() vs CONFIG_PREEMPT_RT=y 3 (3) 2025/08/30 02:20
[PATCH net] net_sched: gen_estimator: 2 (2) 2025/08/26 18:06
Last patch testing requests (2)
Created Duration User Patch Repo Result
2025/08/30 00:59 26m hdanton@sina.com patch upstream OK log
2025/08/26 15:50 24m edumazet@google.com patch upstream OK log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 16 at ./include/linux/seqlock.h:221 __seqprop_assert include/linux/seqlock.h:221 [inline]
WARNING: CPU: 0 PID: 16 at ./include/linux/seqlock.h:221 est_timer+0x6dc/0x9f0 net/core/gen_estimator.c:93
Modules linked in:
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__seqprop_assert include/linux/seqlock.h:221 [inline]
RIP: 0010:est_timer+0x6dc/0x9f0 net/core/gen_estimator.c:93
Code: ff c7 42 80 3c 23 00 74 08 4c 89 f7 e8 7d 35 41 f9 4d 89 3e 42 80 3c 23 00 0f 85 54 ff ff ff e9 57 ff ff ff e8 95 fd e1 f8 90 <0f> 0b 90 e9 63 fd ff ff 44 89 e1 80 e1 07 38 c1 0f 8c 65 fa ff ff
RSP: 0018:ffffc900001577a0 EFLAGS: 00010246
RAX: ffffffff88dc5ebb RBX: 0000000000000001 RCX: ffff88801ae85940
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100
RBP: ffffc900001578b0 R08: 0000000000000000 R09: 0000000000000100
R10: dffffc0000000000 R11: fffff5200002af0a R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888027ab4e68
FS:  0000000000000000(0000) GS:ffff8881268c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000005840 CR3: 000000003732e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers kernel/time/timer.c:2372 [inline]
 __run_timer_base+0x648/0x970 kernel/time/timer.c:2384
 run_timer_base kernel/time/timer.c:2393 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
 handle_softirqs+0x22c/0x710 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 run_ktimerd+0xcf/0x190 kernel/softirq.c:1043
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (400):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/29 13:21 upstream 07d9df80082b 3e1beec6 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/27 06:40 upstream fab1beda7597 e12e5ba4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/24 13:48 upstream 8d245acc1e88 bf27483f .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/24 11:07 upstream 8d245acc1e88 bf27483f .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/09/02 01:31 upstream b320789d6883 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/09/01 22:17 upstream b320789d6883 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/09/01 15:23 upstream b320789d6883 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/09/01 12:53 upstream b320789d6883 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/09/01 12:50 upstream b320789d6883 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/09/01 09:51 upstream b320789d6883 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/09/01 01:57 upstream 5c3b3264e585 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/31 23:35 upstream 5c3b3264e585 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/31 20:08 upstream 5c3b3264e585 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/31 06:20 upstream c8bc81a52d5a 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/31 06:20 upstream c8bc81a52d5a 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/31 04:46 upstream c8bc81a52d5a 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 23:02 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 22:52 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 22:47 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 20:49 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 18:26 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 18:18 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 18:18 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 17:11 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 15:23 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 12:04 upstream fb679c832b64 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 03:15 upstream fb679c832b64 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 02:56 upstream fb679c832b64 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/30 01:23 upstream fb679c832b64 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/29 23:11 upstream fb679c832b64 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/29 20:45 upstream fb679c832b64 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/29 20:39 upstream fb679c832b64 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/29 12:55 upstream 07d9df80082b 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/29 11:02 upstream 07d9df80082b 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/29 05:53 upstream 07d9df80082b 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/29 05:53 upstream 07d9df80082b 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/29 01:02 upstream 07d9df80082b 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 22:07 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 17:59 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 16:15 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 15:02 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 13:30 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 11:22 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 11:21 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 07:14 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 06:12 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 03:37 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
2025/08/28 01:16 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in est_timer
* Struck through repros no longer work on HEAD.