syzbot

INFO: task udevd:1743 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:24968 pid:1743  ppid:5139   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 io_schedule+0x80/0xd0 kernel/sched/core.c:9023
 folio_wait_bit_common+0x714/0xfa0 mm/filemap.c:1329
 folio_put_wait_locked mm/filemap.c:1493 [inline]
 do_read_cache_folio+0x1c0/0x7d0 mm/filemap.c:3786
 read_mapping_folio include/linux/pagemap.h:898 [inline]
 read_part_sector+0xd2/0x340 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+0x740/0x1420 block/partitions/core.c:689
 blkdev_get_whole+0x30d/0x390 block/bdev.c:672
 blkdev_get_by_dev+0x279/0x600 block/bdev.c:814
 blkdev_open+0x152/0x360 block/fops.c:589
 do_dentry_open+0x8c6/0x1500 fs/open.c:929
 do_open fs/namei.c:3640 [inline]
 path_openat+0x27f1/0x3230 fs/namei.c:3797
 do_filp_open+0x1f5/0x430 fs/namei.c:3824
 do_sys_openat2+0x134/0x1d0 fs/open.c:1421
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f50174a7407
RSP: 002b:00007ffc226634b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5017c35880 RCX: 00007f50174a7407
RDX: 00000000000a0800 RSI: 0000559ae8d6ca30 RDI: ffffffffffffff9c
RBP: 0000559ae8d4c910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000559ae8d64e00
R13: 0000559ae8d64410 R14: 0000000000000000 R15: 0000559ae8d64e00
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
1 lock held by syslogd/5121:
 #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
2 locks held by getty/5526:
 #0: ffff8880313ba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
3 locks held by kworker/u4:10/31788:
 #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff8880b8e29598 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
1 lock held by udevd/1743:
 #0: ffff8881417574c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 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+0xf3d/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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 49 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:separate_irq_context kernel/locking/lockdep.c:4628 [inline]
RIP: 0010:__lock_acquire+0xe99/0x7d40 kernel/locking/lockdep.c:5121
Code: 0f 5d 00 00 48 8b 44 24 40 8b 18 48 85 db 4c 8b b4 24 a8 00 00 00 74 5a 83 fb 31 0f 83 ff 5d 00 00 48 8d 04 9b 49 8d 5c c6 f8 <48> 89 d8 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 00 5e 00 00 8b 1b
RSP: 0018:ffffc90000ba72c0 EFLAGS: 00000083
RAX: 0000000000000014 RBX: ffff88801ce5c778 RCX: ffffffff81683d13
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911c3500
RBP: ffffc90000ba7508 R08: dffffc0000000000 R09: 1ffffffff22386a0
R10: dffffc0000000000 R11: fffffbfff22386a1 R12: 0000000000000003
R13: ffff88801ce5bc00 R14: ffff88801ce5c6e0 R15: 8682f47c02656506
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005606f2298660 CR3: 000000000cf32000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
 __debug_check_no_obj_freed lib/debugobjects.c:979 [inline]
 debug_check_no_obj_freed+0x13a/0x540 lib/debugobjects.c:1020
 slab_free_hook mm/slub.c:1786 [inline]
 slab_free_freelist_hook+0xd2/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843
 ieee80211_ibss_rx_queued_mgmt+0x1a9e/0x2c80 net/mac80211/ibss.c:-1
 ieee80211_iface_process_skb net/mac80211/iface.c:1655 [inline]
 ieee80211_iface_work+0x717/0xc70 net/mac80211/iface.c:1709
 cfg80211_wiphy_work+0x225/0x260 net/wireless/core.c:437
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 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
 </TASK>