INFO: task udevd:10975 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25360 pid:10975 ppid: 3557 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 wait_on_page_bit_common+0x8bf/0xeb0 mm/filemap.c:1356 wait_on_page_bit mm/filemap.c:1417 [inline] wait_on_page_locked include/linux/pagemap.h:688 [inline] wait_on_page_read mm/filemap.c:3437 [inline] do_read_cache_page+0xae6/0x1010 mm/filemap.c:3480 read_mapping_page include/linux/pagemap.h:515 [inline] read_part_sector+0xd7/0x4c0 block/partitions/core.c:726 adfspart_check_ICS+0xc3/0xe90 block/partitions/acorn.c:360 check_partition block/partitions/core.c:148 [inline] blk_add_partitions block/partitions/core.c:611 [inline] bdev_disk_changed+0x936/0x1690 block/partitions/core.c:697 blkdev_get_whole+0x2f9/0x390 block/bdev.c:678 blkdev_get_by_dev+0x2da/0xa50 block/bdev.c:823 blkdev_open+0x128/0x2c0 block/fops.c:466 do_dentry_open+0x7f7/0xf90 fs/open.c:826 do_open fs/namei.c:3659 [inline] path_openat+0x2718/0x2fb0 fs/namei.c:3793 do_filp_open+0x1df/0x400 fs/namei.c:3820 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f0bb0012407 RSP: 002b:00007ffd960e8c60 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f0baff24880 RCX: 00007f0bb0012407 RDX: 00000000000a0800 RSI: 00005588b7b8b8f0 RDI: ffffffffffffff9c RBP: 00005588b7b60910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005588b7b85b10 R13: 00005588b7b78410 R14: 00007ffd960e8d28 R15: 00005588b7b85b10 Showing all locks held in the system: 2 locks held by kworker/1:0/21: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90000db7d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 1 lock held by khungtaskd/27: #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3942: #0: ffff88807f03a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 3 locks held by syz-executor/4172: 3 locks held by kworker/0:20/6545: 1 lock held by udevd/10975: #0: ffff88802044c518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x162/0xa50 block/bdev.c:816 3 locks held by syz.9.2089/14051: 2 locks held by dhcpcd/14124: #0: ffff88806465c120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88806465c120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3243 #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: bridge0: port 1(bridge_slave_0) hold timer expired bridge0: port 3(syz_tun) hold timer expired NMI backtrace for cpu 1 CPU: 1 PID: 13156 Comm: syz.0.1839 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:number+0xde/0xef0 lib/vsprintf.c:460 Code: 00 00 00 00 00 ff 00 00 49 21 c4 48 bf 00 00 00 00 00 0a 00 00 4c 89 e6 e8 cf d5 6c fd 48 b8 00 00 00 00 00 0a 00 00 49 39 c4 <4c> 8b 64 24 50 0f 95 c0 20 d8 88 44 24 0f 31 ff 4c 89 e6 e8 aa d5 RSP: 0018:ffffc90000dd0280 EFLAGS: 00000246 RAX: 00000a0000000000 RBX: 0000000000000000 RCX: ffff88801be35940 RDX: 0000000000000100 RSI: 00000a0000000000 RDI: 00000a0000000000 RBP: ffffc90000dd03a0 R08: ffff88801be35940 R09: 0000000000000012 R10: 0000000000000012 R11: 0000000000000100 R12: 00000a0000000000 R13: 00000000ffff0a00 R14: ffffc90000dd0681 R15: ffff0a0000000509 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe5c16c8e20 CR3: 000000000c08e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x12d3/0x1c20 lib/vsprintf.c:2877 sprintf+0xe4/0x140 lib/vsprintf.c:3013 print_time kernel/printk/printk.c:1274 [inline] info_print_prefix+0x168/0x360 kernel/printk/printk.c:1300 record_print_text kernel/printk/printk.c:1349 [inline] console_unlock+0x650/0x10f0 kernel/printk/printk.c:2725 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xda/0x130 kernel/printk/printk.c:2299 __dynamic_pr_debug+0x196/0x240 lib/dynamic_debug.c:619 br_hold_timer_expired+0x153/0x170 net/bridge/br_stp_timer.c:132 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 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:_compound_head include/linux/page-flags.h:198 [inline] RIP: 0010:virt_to_head_page include/linux/mm.h:913 [inline] RIP: 0010:kmem_cache_free+0x52/0x210 mm/slub.c:3520 Code: 84 23 01 00 00 49 89 c7 4c 89 f7 e8 18 8d 78 ff 49 89 c5 49 c1 ed 06 49 83 e5 c0 48 b9 00 00 00 00 00 ea ff ff 49 8b 44 0d 08 01 0f 85 15 01 00 00 49 01 cd 4c 8b 64 24 60 4c 89 74 24 18 48 RSP: 0018:ffffc90002f3f7d8 EFLAGS: 00000202 RAX: ffffea00007d9f40 RBX: ffff8880647bd000 RCX: ffffea0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90002f3f908 R08: ffff88801be35940 R09: 0000000000000002 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888071c66dc0 R13: 0000000001c71980 R14: ffff888071c66dc0 R15: ffff88801bbe5140 kfree_skb include/linux/skbuff.h:1118 [inline] unix_release_sock+0x93e/0xc60 net/unix/af_unix.c:587 unix_release+0x88/0xc0 net/unix/af_unix.c:944 __sock_release net/socket.c:651 [inline] sock_close+0xbf/0x210 net/socket.c:1346 __fput+0x212/0x8c0 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x635/0x2110 kernel/exit.c:890 do_group_exit+0x12c/0x2f0 kernel/exit.c:1004 get_signal+0x7eb/0x12e0 kernel/signal.c:2913 arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:157 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe5c08cf98e Code: Unable to access opcode bytes at RIP 0x7fe5c08cf964. RSP: 002b:00007fe5beb24f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fe5beb256c0 RCX: 00007fe5c08cf98e RDX: 00007fe5beb24fb0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fe5c09a606b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe5c0b97218 R14: 00007fe5c0b97180 R15: 00007ffe1f2d2248 wireguard: wg2: Handshake for peer 24 (127.0.0.1:20002) did not complete after 5 seconds, retrying (try 10) bridge0: port 4(veth0) hold timer expired bridge0: port 1(bridge_slave_0) hold timer expired bridge0: port 2(bridge_slave_1) hold timer expired bridge0: port 3(syz_tun) hold timer expired wireguard: wg2: Handshake for peer 61 ([::1]:20001/0%0) did not complete after 5 seconds, retrying (try 2) wireguard: wg0: Handshake for peer 46 ([::1]:20003/0%0) did not complete after 5 seconds, retrying (try 2) virtqueue callback for ffff88801e8ebc00 (ffffffff8444ab50) virtqueue interrupt with no work for ffff88801e8ebb00 virtqueue interrupt with no work for ffff88801e8eba00 wireguard: wg1: Handshake for peer 60 (127.0.0.1:20003) did not complete after 5 seconds, retrying (try 19) wireguard: wg0: Handshake for peer 70 ([::1]:20003/0%0) did not complete after 5 seconds, retrying (try 2) virtqueue callback for ffff888021610c00 (ffffffff85068310) sd 0:0:1:0: cmd ffff888023d16d28 response 0 status 0x0 sense_len 0 No more buffers in queue bridge0: hello timer expired bridge0: hello timer expired bridge0: hello timer expired virtqueue callback for ffff888147e3a500 (ffffffff85491a80) virtqueue callback for ffff888147e3a400 (ffffffff85491b70) No more buffers in queue Sent skb ffff888078d565e8 Receiving skb proto 0x0800 len 52 type 0 No more buffers in queue No more buffers in queue nf_conntrack: normal packet for ffff88802b02a300 tcp_in_window: START tcp_in_window: seq=2229414071 ack=3038409850+(0) sack=3038409850+(0) win=501 end=2229414071 tcp_in_window: sender end=2229414071 maxend=2229478199 maxwin=65408 scale=7 receiver end=3038409850 maxend=3038473910 maxwin=64768 scale=7 tcp_in_window: seq=2229414071 ack=3038409850+(0) sack=3038409850+(0) win=501 end=2229414071 tcp_in_window: sender end=2229414071 maxend=2229478199 maxwin=65408 scale=7 receiver end=3038409850 maxend=3038473910 maxwin=64768 scale=7 tcp_in_window: I=1 II=1 III=1 IV=1 tcp_in_window: res=1 sender end=2229414071 maxend=2229478199 maxwin=65408 receiver end=3038409850 maxend=3038473978 maxwin=64768 tcp_conntracks: syn=0 ack=1 fin=0 rst=0 old=3 new=3 virtqueue callback for ffff88801e8ebc00 (ffffffff8444ab50) virtqueue interrupt with no work for ffff88801e8ebb00 virtqueue interrupt with no work for ffff88801e8eba00