------------[ cut here ]------------
NETDEV WATCHDOG: lec0 (): transmit queue 0 timed out
WARNING: CPU: 0 PID: 9 at net/sched/sch_generic.c:481 dev_watchdog+0x85d/0xa40 net/sched/sch_generic.c:480
Modules linked in:
CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:dev_watchdog+0x85d/0xa40 net/sched/sch_generic.c:480
Code: f6 71 05 01 48 8b 5c 24 20 48 89 df e8 9c d6 e3 ff 48 c7 c7 80 53 22 8b 48 89 de 48 8b 1c 24 48 89 c2 44 89 e1 e8 d3 d8 b0 01 <0f> 0b e9 51 fe ff ff e8 97 a3 73 f9 0f 0b e9 33 fe ff ff 89 d9 80
RSP: 0000:ffffc90000007af0 EFLAGS: 00010246
RAX: 03d854922e0f6300 RBX: ffff88805c7d8448 RCX: ffff88813fe90000
RDX: 0000000000000100 RSI: 0000000000000101 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffc90000007627 R09: 1ffff92000000ec4
R10: dffffc0000000000 R11: fffff52000000ec5 R12: 0000000000000000
R13: ffff88805c7d8540 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd1a117f000 CR3: 000000007bfce000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:find_stack lib/stackdepot.c:209 [inline]
RIP: 0010:stack_depot_save+0x170/0x460 lib/stackdepot.c:280
Code: 9e 82 57 12 89 eb 81 e3 ff ff 0f 00 4d 8b 64 dd 00 4d 85 e4 74 5e 89 f1 eb 09 4d 8b 24 24 4d 85 e4 74 51 41 39 6c 24 08 75 f0 <41> 39 74 24 0c 75 e9 45 31 c0 4e 8b 0c c7 4f 3b 4c c4 18 75 db 49
RSP: 0000:ffffc90000ce6760 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000000abd5e RCX: 0000000000000014
RDX: 0000000000092800 RSI: 0000000000000014 RDI: ffffc90000ce67c0
RBP: 000000004a9abd5e R08: 000000004c0f03d6 R09: 00000000d9351ffa
R10: 0000000000000001 R11: 000000002b7a99b4 R12: ffff88805ef763e0
R13: ffff88823b000000 R14: 00000000951fa53e R15: ffffc90000ce67c0
 kasan_save_stack mm/kasan/common.c:40 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0xa9/0xc0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x15d/0x280 mm/slub.c:3238
 mempool_alloc+0x19d/0x510 mm/mempool.c:393
 bio_alloc_bioset+0x121/0x870 block/bio.c:466
 bio_alloc include/linux/bio.h:424 [inline]
 io_submit_init_bio fs/ext4/page-io.c:403 [inline]
 io_submit_add_bh fs/ext4/page-io.c:428 [inline]
 ext4_bio_write_page+0x1539/0x1f20 fs/ext4/page-io.c:564
 mpage_submit_page+0x17a/0x210 fs/ext4/inode.c:2115
 mpage_process_page_bufs+0x6c6/0x8a0 fs/ext4/inode.c:2229
 mpage_prepare_extent_to_map+0xc48/0x1080 fs/ext4/inode.c:2657
 ext4_writepages+0x9bb/0x2d40 fs/ext4/inode.c:2785
 do_writepages+0x493/0x700 mm/page-writeback.c:2386
 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657
 writeback_sb_inodes+0xaaa/0x1750 fs/fs-writeback.c:1940
 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011
 wb_writeback+0x45e/0xbc0 fs/fs-writeback.c:2116
 wb_check_old_data_flush fs/fs-writeback.c:2216 [inline]
 wb_do_writeback fs/fs-writeback.c:2269 [inline]
 wb_workfn+0xb15/0xf20 fs/fs-writeback.c:2298
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	57                   	push   %rdi
   1:	12 89 eb 81 e3 ff    	adc    -0x1c7e15(%rcx),%cl
   7:	ff 0f                	decl   (%rdi)
   9:	00 4d 8b             	add    %cl,-0x75(%rbp)
   c:	64 dd 00             	fldl   %fs:(%rax)
   f:	4d 85 e4             	test   %r12,%r12
  12:	74 5e                	je     0x72
  14:	89 f1                	mov    %esi,%ecx
  16:	eb 09                	jmp    0x21
  18:	4d 8b 24 24          	mov    (%r12),%r12
  1c:	4d 85 e4             	test   %r12,%r12
  1f:	74 51                	je     0x72
  21:	41 39 6c 24 08       	cmp    %ebp,0x8(%r12)
  26:	75 f0                	jne    0x18
* 28:	41 39 74 24 0c       	cmp    %esi,0xc(%r12) <-- trapping instruction
  2d:	75 e9                	jne    0x18
  2f:	45 31 c0             	xor    %r8d,%r8d
  32:	4e 8b 0c c7          	mov    (%rdi,%r8,8),%r9
  36:	4f 3b 4c c4 18       	cmp    0x18(%r12,%r8,8),%r9
  3b:	75 db                	jne    0x18
  3d:	49                   	rex.WB