syzbot

INFO: task syz.6.7308:22483 blocked for more than 134 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.7308      state:D stack:0     pid:22483 tgid:22483 ppid:16918  flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5945 [inline]
 __schedule+0x1322/0x1df0 kernel/sched/core.c:7791
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x359/0x630 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 exit_aio+0x2df/0x3b0 fs/aio.c:927
 __mmput+0x30/0x320 kernel/fork.c:1346
 mmput+0x55/0x170 kernel/fork.c:1372
 exit_mm kernel/exit.c:574 [inline]
 do_exit+0x918/0x2630 kernel/exit.c:940
 do_group_exit+0x22a/0x300 kernel/exit.c:1095
 __do_sys_exit_group kernel/exit.c:1106 [inline]
 __se_sys_exit_group kernel/exit.c:1104 [inline]
 __x64_sys_exit_group+0x43/0x50 kernel/exit.c:1104
 x64_sys_call+0x2ed2/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f572638ebe9
RSP: 002b:00007ffedf9dc668 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f572638ebe9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffedf9dc6cc R08: 00000008df9dc75f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000232
R13: 00000000000927c0 R14: 00000000000a8ca0 R15: 00007ffedf9dc720
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 ecd017b10525a6fce0a0b730885af6e9bd831db9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
 watchdog+0xd8f/0xed0 kernel/hung_task.c:423
 kthread+0x2c7/0x370 kernel/kthread.c:389
 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 33 Comm: rcuop/1 Not tainted syzkaller #0 ecd017b10525a6fce0a0b730885af6e9bd831db9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:update_stack_state+0x2a4/0x4b0 arch/x86/kernel/unwind_frame.c:261
Code: fc ff df 41 80 3c 07 00 74 08 4c 89 f7 e8 c4 e4 97 00 49 83 3e 00 74 2b 44 3b 6d ac 75 25 48 8b 45 a0 48 39 45 b0 73 1b 31 db <89> d8 48 81 c4 98 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc
RSP: 0018:ffffc900002300f8 EFLAGS: 00000282
RAX: 1ffff92000046052 RBX: ffffc90000230201 RCX: ffffc90000230d01
RDX: ffffc90000230d30 RSI: 1ffff9200004604a RDI: ffffc900002302a0
RBP: ffffc900002301b8 R08: ffffc90000230310 R09: ffffc90000230308
R10: 000000000000000a R11: ffffffff81744330 R12: dffffc0000000000
R13: ffffc90000230270 R14: ffffc90000230288 R15: 1ffff92000046051
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6e39c3650 CR3: 000000015c33e000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 unwind_next_frame+0x3c2/0x750 arch/x86/kernel/unwind_frame.c:315
 arch_stack_walk+0x139/0x170 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:69
 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:565
 unpoison_slab_object mm/kasan/common.c:320 [inline]
 __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:346
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4169 [inline]
 slab_alloc_node mm/slub.c:4218 [inline]
 kmem_cache_alloc_noprof+0x131/0x3a0 mm/slub.c:4227
 skb_clone+0x229/0x460 net/core/skbuff.c:2082
 deliver_clone net/bridge/br_forward.c:125 [inline]
 br_flood+0x661/0x730 net/bridge/br_forward.c:245
 br_handle_frame_finish+0x12bb/0x1720 net/bridge/br_input.c:215
 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
 br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xf48/0x3940 net/core/dev.c:5651
 __netif_receive_skb_one_core net/core/dev.c:5755 [inline]
 __netif_receive_skb net/core/dev.c:5870 [inline]
 process_backlog+0x3e5/0xae0 net/core/dev.c:6206
 __napi_poll+0xd3/0x610 net/core/dev.c:6857
 napi_poll net/core/dev.c:6926 [inline]
 net_rx_action+0x584/0xce0 net/core/dev.c:7048
 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
 __do_softirq+0xf/0x16 kernel/softirq.c:659
 do_softirq+0xa6/0x100 kernel/softirq.c:503
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch+0x5c6/0xd20 kernel/rcu/tree.c:2594
 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
 rcu_nocb_cb_kthread+0x4dc/0xac0 kernel/rcu/tree_nocb.h:957
 kthread+0x2c7/0x370 kernel/kthread.c:389
 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
net_ratelimit: 127665 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e2:09:0d:0b:90:ff, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e2:09:0d:0b:90:ff, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)