INFO: task udevd:4904 blocked for more than 143 seconds. Not tainted 6.11.0-rc1-syzkaller-00033-g25f51b76f90f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:26480 pid:4904 tgid:4904 ppid:2548 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xcda/0x2f80 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 device_lock include/linux/device.h:1009 [inline] uevent_show+0x188/0x3b0 drivers/base/core.c:2743 dev_attr_show+0x53/0xe0 drivers/base/core.c:2437 sysfs_kf_seq_show+0x23e/0x410 fs/sysfs/file.c:59 seq_read_iter+0x4fa/0x12c0 fs/seq_file.c:230 kernfs_fop_read_iter+0x41a/0x590 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x869/0xbd0 fs/read_write.c:476 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f27880afb6a RSP: 002b:00007ffe0c883658 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055a391205e20 RCX: 00007f27880afb6a RDX: 0000000000001000 RSI: 000055a3912313b0 RDI: 0000000000000008 RBP: 000055a391205e20 R08: 0000000000000008 R09: 0000000000000010 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffe0c883b38 R15: 000000000000000a Showing all locks held in the system: 5 locks held by kworker/0:0/8: 1 lock held by khungtaskd/30: #0: ffffffff88cb68a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff88cb68a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff88cb68a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6620 2 locks held by getty/2606: #0: ffff88810e75c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2211 4 locks held by udevd/4904: #0: ffff888118e5eb08 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff888117e52488 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811c0a9698 (kn->active#3){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811cc25190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff88811cc25190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2743 4 locks held by udevd/4914: #0: ffff88811abb99e0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff8881213ac488 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88810f3ade18 (kn->active#3){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888117a49190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888117a49190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2743 8 locks held by kworker/0:4/4971: 1 lock held by syz.3.424/6350: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc1-syzkaller-00033-g25f51b76f90f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf4e/0x1280 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2537 Comm: klogd Not tainted 6.11.0-rc1-syzkaller-00033-g25f51b76f90f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:stack_access_ok+0x4/0x270 arch/x86/kernel/unwind_orc.c:389 Code: ff ff e9 6f fe ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 <41> 55 41 54 55 48 89 f5 53 48 89 fb 4c 8d 63 08 48 83 ec 10 48 89 RSP: 0018:ffffc900016cf4c0 EFLAGS: 00000293 RAX: ffffc900016cfd00 RBX: ffffc900016cf558 RCX: ffffffff811565a9 RDX: 0000000000000008 RSI: ffffc900016cfd00 RDI: ffffc900016cf558 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000004 R10: 0000000000000002 R11: 0000000000000000 R12: ffffffff8aec4a02 R13: ffffc900016cfd08 R14: ffffffff8aec4a06 R15: 0000000000000002 FS: 00007f94194b0380(0000) GS:ffff8881f6300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc0da32010 CR3: 0000000115664000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline] unwind_next_frame+0xd9b/0x23a0 arch/x86/kernel/unwind_orc.c:585 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x6e/0x70 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3988 [inline] slab_alloc_node mm/slub.c:4037 [inline] kmem_cache_alloc_node_noprof+0x13e/0x2e0 mm/slub.c:4080 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:664 alloc_skb include/linux/skbuff.h:1320 [inline] alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6526 sock_alloc_send_pskb+0x7f1/0x980 net/core/sock.c:2815 unix_dgram_sendmsg+0x467/0x19a0 net/unix/af_unix.c:2030 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x47f/0x4e0 net/socket.c:2204 __do_sys_sendto net/socket.c:2216 [inline] __se_sys_sendto net/socket.c:2212 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2212 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f94196129b5 Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffce0609038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f94196129b5 RDX: 000000000000004a RSI: 00005556cfcc9bd0 RDI: 0000000000000003 RBP: 00005556cfcc12c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007f94197a0212 R14: 00007ffce0609138 R15: 0000000000000000