INFO: task udevd:8824 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:25712 pid:8824 ppid:5156 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 io_schedule+0x80/0xd0 kernel/sched/core.c:9022 folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7e0 mm/filemap.c:3771 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x350 block/partitions/core.c:718 adfspart_check_POWERTEC+0x8d/0xf00 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+0x73a/0x1410 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:655 blkdev_get_by_dev+0x279/0x600 block/bdev.c:797 blkdev_open+0x152/0x360 block/fops.c:589 do_dentry_open+0x8c6/0x1500 fs/open.c:929 do_open fs/namei.c:3632 [inline] path_openat+0x274b/0x3190 fs/namei.c:3789 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419 do_sys_open fs/open.c:1434 [inline] __do_sys_openat fs/open.c:1450 [inline] __se_sys_openat fs/open.c:1445 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1445 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc0e4fd0407 RSP: 002b:00007ffc038b4cc0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc0e4f44880 RCX: 00007fc0e4fd0407 RDX: 00000000000a0800 RSI: 000055afd6b0cce0 RDI: ffffffffffffff9c RBP: 000055afd6afd910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055afd6b27690 R13: 000055afd6b15410 R14: 0000000000000000 R15: 000055afd6b27690 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:8/3536: 2 locks held by getty/5549: #0: ffff88814cab90a0 (&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+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by udevd/8824: #0: ffff88814179c4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788 3 locks held by kworker/0:0/11262: 1 lock held by syz.2.1831/12260: 2 locks held by syz.1.1833/12264: #0: ffffffff8cbed1a8 (sched_core_mutex){+.+.}-{3:3}, at: sched_core_get+0x52/0x180 kernel/sched/core.c:419 #1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 3 locks held by syz.0.1834/12268: ============================================= 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 08/18/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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: 5786 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:60 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:127 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline] RIP: 0010:kasan_check_range+0x41/0x290 mm/kasan/generic.c:187 Code: 54 53 4c 8d 04 37 49 39 f8 0f 82 5a 02 00 00 49 89 f9 49 c1 e9 2f 41 81 f9 ff ff 01 00 0f 82 46 02 00 00 49 89 ff 49 c1 ef 03 <49> ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 ff c8 4d 89 c1 49 c1 RSP: 0018:ffffc90003bb74a0 EFLAGS: 00000a06 RAX: ffffc90003bb7c01 RBX: 0000000000000010 RCX: ffffffff813ab908 RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90003bb7618 RBP: 0000000000000000 R08: ffffc90003bb7628 R09: 000000000001ffff R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90003bb75c8 R13: dffffc0000000000 R14: ffffc90003bb7618 R15: 1ffff92000776ec3 FS: 000055556b441500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556b464608 CR3: 0000000062e2c000 CR4: 00000000003506e0 Call Trace: __asan_memset+0x22/0x40 mm/kasan/shadow.c:84 unwind_next_frame+0x1648/0x2970 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc_lru+0x115/0x2e0 mm/slub.c:3526 xas_alloc lib/xarray.c:375 [inline] xas_expand lib/xarray.c:582 [inline] xas_create+0x607/0x1720 lib/xarray.c:653 xas_store+0xa6/0x19e0 lib/xarray.c:787 __xa_alloc+0x143/0x220 lib/xarray.c:1846 __xa_alloc_cyclic+0x91/0x2d0 lib/xarray.c:1885 xa_alloc_cyclic include/linux/xarray.h:977 [inline] simple_offset_add+0x12a/0x1d0 fs/libfs.c:296 shmem_mknod+0xf7/0x1d0 mm/shmem.c:3246 shmem_mkdir+0x33/0x60 mm/shmem.c:3298 vfs_mkdir+0x296/0x440 fs/namei.c:4113 do_mkdirat+0x1d4/0x440 fs/namei.c:4136 __do_sys_mkdirat fs/namei.c:4151 [inline] __se_sys_mkdirat fs/namei.c:4149 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4149 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fcfdc78d617 Code: 73 01 c3 48 c7 c1 a8 ff ff ff 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 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd2996ba08 EFLAGS: 00000202 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007ffd2996ba60 RCX: 00007fcfdc78d617 RDX: 00000000000001ff RSI: 00007ffd2996ba60 RDI: 00000000ffffff9c RBP: 00007ffd2996ba4c R08: 0000000000000005 R09: 00007ffd2996b7a5 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000001a3 R13: 00000000000927c0 R14: 00000000000c485b R15: 00007ffd2996baa0