INFO: task syz.3.2899:15796 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.2899 state:D stack:26168 pid:15796 tgid:15795 ppid:5615 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820 bdev_open+0x41a/0xe40 block/bdev.c:953 blkdev_open+0x34e/0x4f0 block/fops.c:697 do_dentry_open+0x6ab/0x14d0 fs/open.c:947 vfs_open+0x82/0x3f0 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4858 do_file_open+0x20e/0x430 fs/namei.c:4887 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcbcef5d68e RSP: 002b:00007fcbcfe34b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fcbcfe356c0 RCX: 00007fcbcef5d68e RDX: 0000000000000000 RSI: 00007fcbcfe34c00 RDI: ffffffffffffff9c RBP: 00007fcbcfe34c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fcbcf216038 R14: 00007fcbcf215fa0 R15: 00007ffd91908098 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5386: #0: ffff88803889f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5926: #0: ffff888027e00350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:953 1 lock held by syz.3.2899/15796: #0: ffff888027e00350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:953 2 locks held by syz-executor/16001: #0: ffff888039e900d8 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888039e900d8 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888039e900d8 (&type->s_umount_key#88){++++}-{4:4}, at: deactivate_super fs/super.c:508 [inline] #0: ffff888039e900d8 (&type->s_umount_key#88){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505 #1: ffffffff8e7f10a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 1 lock held by syz.4.3418/18017: #0: ffffffff8e7f0f78 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 1 lock held by syz.1.3421/18033: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 4983 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__unwind_start+0x2e0/0x7f0 arch/x86/kernel/unwind_orc.c:795 Code: 00 fc ff df 4c 89 f2 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e f9 02 00 00 41 c7 06 00 00 00 00 48 83 c4 18 5b 5d 41 5c <41> 5d 41 5e 41 5f c3 cc cc cc cc 4d 85 e4 0f 85 b6 fd ff ff 48 8d RSP: 0018:ffffc9000341f6a8 EFLAGS: 00000296 RAX: 1ffff92000683ee0 RBX: ffffc9000341f6c8 RCX: ffffc9000341f760 RDX: ffffc90003420000 RSI: ffffffff8deea6e6 RDI: ffff88807cda04c4 RBP: ffffc9000341f758 R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 000000000000aee3 R12: ffffffff81f2f5b0 R13: fffff52000683eda R14: ffffc9000341f6c8 R15: ffffc9000341f6d0 FS: 00007fb7ecfb7880(0000) GS:ffff888124487000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555710b1ac8 CR3: 0000000020b96000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5296 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5308 kmalloc_noprof include/linux/slab.h:954 [inline] tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827 security_inode_getattr+0x116/0x280 security/security.c:1895 vfs_getattr fs/stat.c:259 [inline] vfs_fstat+0x4b/0xe0 fs/stat.c:281 __do_sys_newfstat+0x8b/0x110 fs/stat.c:551 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb7ec911ad7 Code: 73 01 c3 48 8b 0d 21 f3 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 05 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 RSP: 002b:00007ffc9b083328 EFLAGS: 00000297 ORIG_RAX: 0000000000000005 RAX: ffffffffffffffda RBX: 000055753e589d70 RCX: 00007fb7ec911ad7 RDX: 00007fb7ec9efea0 RSI: 00007ffc9b083330 RDI: 000000000000000c RBP: 00007fb7ec9efff0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 000000000000000a R13: 0000000000003fff R14: 0000000000000000 R15: 000055753e589d70