INFO: task udevd:16319 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25432 pid:16319 ppid:5145 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6701 schedule+0xbd/0x170 kernel/sched/core.c:6775 io_schedule+0x80/0xd0 kernel/sched/core.c:9024 folio_wait_bit_common+0x881/0xfa0 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7f0 mm/filemap.c:3791 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x350 block/partitions/core.c:718 adfspart_check_POWERTEC+0x93/0xed0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:600 [inline] bdev_disk_changed+0x755/0x1450 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:668 blkdev_get_by_dev+0x3a9/0x610 block/bdev.c:810 blkdev_open+0x14e/0x360 block/fops.c:589 do_dentry_open+0x880/0x14b0 fs/open.c:929 do_open fs/namei.c:3683 [inline] path_openat+0x284f/0x3270 fs/namei.c:3844 do_filp_open+0x1f2/0x430 fs/namei.c:3871 do_sys_openat2+0x134/0x1d0 fs/open.c:1422 do_sys_open fs/open.c:1437 [inline] __do_sys_openat fs/open.c:1453 [inline] __se_sys_openat fs/open.c:1448 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1448 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1212ea7407 RSP: 002b:00007ffe3dd192b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f1213646880 RCX: 00007f1212ea7407 RDX: 00000000000a0800 RSI: 00005642b6e756d0 RDI: ffffffffffffff9c RBP: 00005642b6e75910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005642b6e8de00 R13: 00005642b6e8d410 R14: 0000000000000000 R15: 00005642b6e8de00 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6635 2 locks held by getty/5535: #0: ffff8880319aa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217 1 lock held by udevd/16319: #0: ffff8880218954c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801 2 locks held by syz.1.5435/22740: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 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+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf59/0xfa0 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 22740 Comm: syz.1.5435 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:check_region_inline mm/kasan/generic.c:-1 [inline] RIP: 0010:kasan_check_range+0x12/0x290 mm/kasan/generic.c:187 Code: 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc 66 0f 1f 00 b0 01 48 85 f6 0f 84 b4 01 00 00 55 41 57 <41> 56 41 55 41 54 53 4c 8d 04 37 49 39 f8 0f 82 13 02 00 00 49 89 RSP: 0018:ffffc9000e506bc8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 00000000000000ac RCX: ffffffff8168af16 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911eb510 RBP: ffffc9000e506e28 R08: dffffc0000000000 R09: 1ffffffff223d6a2 R10: dffffc0000000000 R11: fffffbfff223d6a3 R12: 1c1026a7fb53f1a1 R13: ffff888056d60000 R14: 00000000fb53f1a1 R15: ffff888056d60b58 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f969dfef2f8 CR3: 00000000291b4000 CR4: 00000000003506e0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class kernel/locking/lockdep.c:228 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:3781 [inline] validate_chain kernel/locking/lockdep.c:3837 [inline] __lock_acquire+0x1336/0x7d80 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5756 do_write_seqcount_begin_nested include/linux/seqlock.h:515 [inline] do_write_seqcount_begin include/linux/seqlock.h:541 [inline] psi_write_begin kernel/sched/psi.c:179 [inline] psi_account_irqtime+0x236/0x810 kernel/sched/psi.c:1034 __schedule+0x8c8/0x4660 kernel/sched/core.c:6695 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7011 irqentry_exit+0x67/0x70 kernel/entry/common.c:441 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x80 kernel/kcov.c:317 Code: c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 0f 1e fa 48 8b 04 24 65 48 8b 0d 60 28 7c 7e 65 8b 15 61 28 7c RSP: 0018:ffffc9000e507380 EFLAGS: 00000246 RAX: ffffffff817626ba RBX: ffffc9000e507440 RCX: ffff888056d60000 RDX: 0000000000000000 RSI: ffffffff817626ba RDI: 0000000000000000 RBP: ffffc9000e507410 R08: ffff888056d60000 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff817626ba R13: ffffc9000e507798 R14: ffffffff81762710 R15: ffffc9000e507388 arch_stack_walk+0x12a/0x190 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x290 mm/slub.c:3852 vma_lock_free kernel/fork.c:473 [inline] __vm_area_free+0xe4/0x110 kernel/fork.c:529 remove_vma mm/mmap.c:146 [inline] exit_mmap+0x61d/0xb90 mm/mmap.c:3326 __mmput+0x118/0x3a0 kernel/fork.c:1362 exit_mm+0x23f/0x340 kernel/exit.c:576 do_exit+0x909/0x2530 kernel/exit.c:877 do_group_exit+0x22d/0x2f0 kernel/exit.c:1032 get_signal+0x12a6/0x1390 kernel/signal.c:2915 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 __syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9f4599e159 Code: Unable to access opcode bytes at 0x7f9f4599e12f. RSP: 002b:00007f9f468170e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f9f45c26098 RCX: 00007f9f4599e159 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9f45c26098 RBP: 00007f9f45c26090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9f45c26128 R14: 00007fff7758d4d0 R15: 00007fff7758d5b8