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WARNING in free_netdev (4)

Status: auto-obsoleted due to no activity on 2026/04/27 07:44
Subsystems: net
[Documentation on labels]
First crash: 100d, last: 100d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
fd53cd6d-ee8b-4aa5-94f3-9b7633b6d5a6 repro 💥 WARNING in free_netdev (4) 2026/03/10 12:16 2026/03/10 12:16 2026/03/10 12:17 5c03941b7fba0fd3b0326afc981322c89fe9ba52+ unexpected git log output: "warning: unable to access '/root/.config/git/attributes': Permission denied\nwarning: unable to access '/root/.config/git/attributes': Permission denied\n24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7\nLinux 6.19-rc6\ntorvalds@linux-foundation.org\nLinus Torvalds\nSun Jan 18 15:42:45 2026 -0800\n90a855e75a99f2932b19f4d04bac1edef158d95e\nSun Jan 18 15:42:45 2026 -0800\n"
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in free_netdev (3) net -1 3 331d 347d 0/29 closed as invalid on 2025/06/27 12:28
upstream WARNING in free_netdev net -1 4080 1527d 1569d 20/29 fixed on 2022/03/08 16:11
upstream WARNING in free_netdev (2) net -1 syz 259 362d 467d 28/29 fixed on 2025/05/06 15:33

Sample crash report:
netdevsim netdevsim4 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock))
WARNING: kernel/locking/mutex-debug.c:107 at mutex_destroy+0x95/0xf0 kernel/locking/mutex-debug.c:107, CPU#0: kworker/u8:32/12582
Modules linked in:
CPU: 0 UID: 0 PID: 12582 Comm: kworker/u8:32 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: netns cleanup_net
RIP: 0010:mutex_destroy+0x9c/0xf0 kernel/locking/mutex-debug.c:107
Code: c7 c0 a4 5e 82 8f 48 c1 e8 03 42 0f b6 04 30 84 c0 75 45 83 3d 08 7c e4 0d 00 75 13 48 8d 3d fb 8e e7 0d 48 c7 c6 00 2a 6b 8b <67> 48 0f b9 3a 90 eb 99 48 c7 c1 20 94 8b 99 80 e1 07 80 c1 03 38
RSP: 0018:ffffc9000b6e75d0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888028f54cd0 RCX: ffff88802b18bd00
RDX: 0000000000000000 RSI: ffffffff8b6b2a00 RDI: ffffffff8f8571a0
RBP: 0000000000000000 R08: ffffffff8f825ea3 R09: 1ffffffff1f04bd4
R10: dffffc0000000000 R11: fffffbfff1f04bd5 R12: ffff888028f546a0
R13: 1ffff110051ea8d4 R14: dffffc0000000000 R15: ffff888028f54bb8
FS:  0000000000000000(0000) GS:ffff888125e1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f11b6677e9c CR3: 00000000afdd4000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 free_netdev+0x53e/0x6d0 net/core/dev.c:12189
 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1528
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1540 [inline]
 nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1763
 nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:1038
 devlink_reload+0x1b6/0x8d0 net/devlink/dev.c:461
 devlink_pernet_pre_exit+0x1d9/0x3d0 net/devlink/core.c:509
 ops_pre_exit_list net/core/net_namespace.c:161 [inline]
 ops_undo_list+0x187/0x990 net/core/net_namespace.c:234
 cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
----------------
Code disassembly (best guess):
   0:	c7 c0 a4 5e 82 8f    	mov    $0x8f825ea4,%eax
   6:	48 c1 e8 03          	shr    $0x3,%rax
   a:	42 0f b6 04 30       	movzbl (%rax,%r14,1),%eax
   f:	84 c0                	test   %al,%al
  11:	75 45                	jne    0x58
  13:	83 3d 08 7c e4 0d 00 	cmpl   $0x0,0xde47c08(%rip)        # 0xde47c22
  1a:	75 13                	jne    0x2f
  1c:	48 8d 3d fb 8e e7 0d 	lea    0xde78efb(%rip),%rdi        # 0xde78f1e
  23:	48 c7 c6 00 2a 6b 8b 	mov    $0xffffffff8b6b2a00,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	90                   	nop
  30:	eb 99                	jmp    0xffffffcb
  32:	48 c7 c1 20 94 8b 99 	mov    $0xffffffff998b9420,%rcx
  39:	80 e1 07             	and    $0x7,%cl
  3c:	80 c1 03             	add    $0x3,%cl
  3f:	38                   	.byte 0x38

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/19 06:03 upstream 24d479d26b25 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in free_netdev
* Struck through repros no longer work on HEAD.