syzbot


upstream test error: WARNING in enqueue_to_backlog

Status: internal: reported on 2026/02/12 15:17
Subsystems: net
[Documentation on labels]
Fix commit: net: fix backlog_unlock_irq_restore() vs CONFIG_PREEMPT_RT
Patched 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-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-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-upstream-gce-arm64]
First crash: 48d, last: 41d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
f5f5a579-5cd3-47c7-92bb-496047bd38f8 repro upstream test error: WARNING in enqueue_to_backlog 2026/03/06 19:52 2026/03/06 19:52 2026/03/06 20:01 31e9c887f7dc24e04b3ca70d0d54fc34141844b0

Sample crash report:
------------[ cut here ]------------
raw_local_irq_restore() called with IRQs enabled
WARNING: kernel/locking/irqflag-debug.c:10 at warn_bogus_irq_restore+0xc/0x20 kernel/locking/irqflag-debug.c:10, CPU#0: aoe_tx0/1321
Modules linked in:
CPU: 0 UID: 0 PID: 1321 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:warn_bogus_irq_restore+0xc/0x20 kernel/locking/irqflag-debug.c:10
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 90 48 8d 3d 64 3e 4b 04 <67> 48 0f b9 3a 90 c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90
RSP: 0018:ffffc90005ecf728 EFLAGS: 00010293
RAX: ffffffff88f540b0 RBX: 0000000000000001 RCX: ffff8880288e9e40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8f6d4110
RBP: ffff8880b883d960 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1ed4417 R12: ffff8880b883d978
R13: dffffc0000000000 R14: 0000000000000200 R15: ffff8880b883d958
FS:  0000000000000000(0000) GS:ffff888126342000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b6819e5660 CR3: 000000003e5f6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 backlog_unlock_irq_restore net/core/dev.c:253 [inline]
 enqueue_to_backlog+0x525/0xcf0 net/core/dev.c:5347
 netif_rx_internal+0x120/0x590 net/core/dev.c:5659
 __netif_rx+0xa9/0x110 net/core/dev.c:5679
 loopback_xmit+0x43a/0x660 drivers/net/loopback.c:90
 __netdev_start_xmit include/linux/netdevice.h:5275 [inline]
 netdev_start_xmit include/linux/netdevice.h:5284 [inline]
 xmit_one net/core/dev.c:3864 [inline]
 dev_hard_start_xmit+0x2f2/0x8b0 net/core/dev.c:3880
 __dev_queue_xmit+0x16f4/0x39e0 net/core/dev.c:4829
 dev_queue_xmit include/linux/netdevice.h:3384 [inline]
 tx+0x6b/0x190 drivers/block/aoe/aoenet.c:62
 kthread+0x1e0/0x3f0 drivers/block/aoe/aoecmd.c:1241
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	cc                   	int3
   1:	cc                   	int3
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	cc                   	int3
   6:	cc                   	int3
   7:	cc                   	int3
   8:	cc                   	int3
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	cc                   	int3
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	f3 0f 1e fa          	endbr64
  22:	90                   	nop
  23:	48 8d 3d 64 3e 4b 04 	lea    0x44b3e64(%rip),%rdi        # 0x44b3e8e
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	90                   	nop
  30:	c3                   	ret
  31:	cc                   	int3
  32:	cc                   	int3
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	cc                   	int3
  3c:	cc                   	int3
  3d:	cc                   	int3
  3e:	90                   	nop
  3f:	90                   	nop

Crashes (70):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/19 18:15 upstream 2b7a25df823d c8d8c52d .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/19 15:19 upstream 2b7a25df823d 73a252ac .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/19 07:46 upstream 2b7a25df823d 746545b8 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/19 03:09 upstream 956b9cbd7f15 746545b8 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/19 00:28 upstream 956b9cbd7f15 77d4d919 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/18 23:25 upstream fa2827e72cfc 77d4d919 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/18 19:41 upstream 23b0f90ba871 77d4d919 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/18 16:05 upstream 2961f841b025 77d4d919 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/18 14:59 upstream 2961f841b025 77d4d919 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/18 03:41 upstream 2961f841b025 39751c21 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/18 00:31 upstream 2961f841b025 06ec4f7b .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/17 22:35 upstream e81dd54f62c7 39751c21 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/17 21:06 upstream e81dd54f62c7 06ec4f7b .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/17 18:10 upstream 970296997869 39751c21 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/17 15:37 upstream 970296997869 06ec4f7b .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/17 05:31 upstream 970296997869 e439b951 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/17 03:00 upstream 970296997869 e439b951 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/17 01:34 upstream 970296997869 5d52cba5 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/16 22:49 upstream 57d76ceccee4 5d52cba5 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/16 21:18 upstream 57d76ceccee4 5d52cba5 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/16 15:55 upstream 0f2acd3148e0 5d52cba5 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/16 14:47 upstream 0f2acd3148e0 5d52cba5 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/16 04:31 upstream 0f2acd3148e0 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/16 04:25 upstream 0f2acd3148e0 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/15 20:25 upstream 26a4cfaff82a 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/15 19:39 upstream 26a4cfaff82a 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/15 18:35 upstream bb7a3fc2c976 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/15 17:40 upstream bb7a3fc2c976 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/14 23:38 upstream ca4ee40bf13d 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/14 23:19 upstream ca4ee40bf13d 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/14 21:42 upstream 64275e9fda37 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/14 21:20 upstream 64275e9fda37 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/14 18:38 upstream 3e48a11675c5 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/14 18:21 upstream 3e48a11675c5 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/14 04:34 upstream 770aaedb461a 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/14 04:19 upstream 770aaedb461a 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/14 00:47 upstream f50822fd8675 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/14 00:40 upstream f50822fd8675 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/13 22:06 upstream 44331bd6a610 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/13 21:01 upstream 44331bd6a610 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/13 19:38 upstream cd7a5651db26 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/13 19:29 upstream cd7a5651db26 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/13 17:38 upstream cee73b1e840c 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/13 17:13 upstream cee73b1e840c 1e62d198 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/13 05:42 upstream cee73b1e840c 6a673c50 .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/13 05:06 upstream cee73b1e840c 6a673c50 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/13 04:15 upstream cee73b1e840c 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/13 04:10 upstream cee73b1e840c 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/13 02:52 upstream 7449f86bafcd 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/13 02:32 upstream 7449f86bafcd 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/13 02:05 upstream 2c75a8d92cf1 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/13 01:54 upstream 2c75a8d92cf1 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/12 23:40 upstream 582a1ef360a0 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/12 23:32 upstream 582a1ef360a0 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/12 21:44 upstream 136114e0abf0 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/12 21:30 upstream 136114e0abf0 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/12 20:20 upstream 541c43310e85 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/12 19:52 upstream 541c43310e85 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/12 19:28 upstream 37a93dd5c49b 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root upstream test error: WARNING in enqueue_to_backlog
2026/02/12 16:53 upstream 37a93dd5c49b 504cb1bf .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
2026/02/12 15:16 upstream 37a93dd5c49b 76a109e2 .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-fs upstream test error: WARNING in enqueue_to_backlog
* Struck through repros no longer work on HEAD.