syzbot

INFO: task udevd:8621 blocked for more than 143 seconds.
      Not tainted 6.6.101-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:23688 pid:8621  ppid:5157   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 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+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: 0033:0x7fbd772a7407
RSP: 002b:00007ffd366d39d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbd7794e880 RCX: 00007fbd772a7407
RDX: 00000000000a0800 RSI: 0000559462da8160 RDI: ffffffffffffff9c
RBP: 0000559462d96910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000559462dc1600
R13: 0000559462dae420 R14: 0000000000000000 R15: 0000559462dc1600
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:4/59:
 #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc900015a7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc900015a7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffffffff8dfaea90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606
 #3: ffffffff8cd35a40 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089
2 locks held by getty/5542:
 #0: ffff8880311420a0 (&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/8621:
 #0: ffff8880219c34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
2 locks held by kworker/0:2/10987:
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc9000e51fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc9000e51fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by syz.3.3963/21499:
 #0: ffff8880219c34c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1059
1 lock held by sed/22871:

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 22874 Comm: rm Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_preemption_disabled+0x60/0x110 lib/smp_processor_id.c:19
Code: 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 <74> cc 65 4c 8b 3d d6 8b 96 75 41 f6 47 2f 04 74 0a 41 83 bf 10 04
RSP: 0018:ffffc9000fcb76e0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888026e83c00 RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff8aaac720 RDI: ffffffff8afc6780
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff2e576ac R12: ffff88806a278b20
R13: 0000000000000246 R14: ffff88806a278b20 R15: 00000000ffffffff
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff435067440 CR3: 000000004f3e2000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
 lock_is_held_type+0x79/0x190 kernel/locking/lockdep.c:5824
 lock_is_held include/linux/lockdep.h:288 [inline]
 mt_locked lib/maple_tree.c:-1 [inline]
 mt_slot lib/maple_tree.c:812 [inline]
 mas_slot lib/maple_tree.c:845 [inline]
 mas_validate_parent_slot lib/maple_tree.c:7039 [inline]
 mt_validate+0x7b1/0x4530 lib/maple_tree.c:7228
 validate_mm+0xb1/0x420 mm/mmap.c:287
 mmap_region+0x17e5/0x1f80 mm/mmap.c:2943
 do_mmap+0x8d1/0xfd0 mm/mmap.c:1381
 vm_mmap_pgoff+0x1c0/0x400 mm/util.c:556
 ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1427
 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: 0033:0x7ff435341242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007ffcf549e168 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007ff43505f000 RCX: 00007ff435341242
RDX: 0000000000000003 RSI: 0000000000002000 RDI: 00007ff43505f000
RBP: 0000000000000812 R08: 0000000000000003 R09: 000000000000d000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffcf549e228
R13: 00007ff43531e580 R14: 00007ffcf549e5e0 R15: 00000fff9ea93c30
 </TASK>