INFO: task syz.3.135:6738 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.135 state:D stack:26944 pid:6738 tgid:6738 ppid:5801 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x132/0x200 kernel/locking/rwsem.c:1539
filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
do_page_cache_ra mm/readahead.c:333 [inline]
page_cache_ra_order+0x2a5/0x4b0 mm/readahead.c:538
do_sync_mmap_readahead+0x570/0x6a0 mm/filemap.c:3405
filemap_fault+0x6eb/0x1330 mm/filemap.c:3554
__do_fault+0x138/0x390 mm/memory.c:5364
do_shared_fault mm/memory.c:5863 [inline]
do_fault mm/memory.c:5937 [inline]
do_pte_missing+0x623/0x29e0 mm/memory.c:4477
handle_pte_fault mm/memory.c:6317 [inline]
__handle_mm_fault mm/memory.c:6455 [inline]
handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6624
do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fdba058b62b
RSP: 002b:00007ffe133298c8 EFLAGS: 00010202
RAX: 0000200000000180 RBX: 0000000000000004 RCX: 0000000000347478
RDX: 0000000000000005 RSI: 0000000034747865 RDI: 0000200000000180
RBP: fffffffffffffffe R08: 0000001b2e220000 R09: 0000000000000001
R10: 7ffffffffffffffa R11: 0000000000000009 R12: 00007ffe133299f0
R13: 00007fdba083609c R14: 000000000002ad7e R15: 00007fdba0836090
Showing all locks held in the system:
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/37:
#0: ffffffff8ddcba40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcba40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcba40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:4/87:
2 locks held by getty/5557:
#0: ffff8880378f80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5849:
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x11a/0x360 fs/btrfs/super.c:2265
1 lock held by udevd/5856:
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x11a/0x360 fs/btrfs/super.c:2265
1 lock held by udevd/6006:
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x11a/0x360 fs/btrfs/super.c:2265
2 locks held by syz.1.19/6022:
1 lock held by syz.3.135/6738:
#0: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
#0: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline]
#0: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x4b0 mm/readahead.c:538
1 lock held by syz.4.212/7470:
#0: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
#0: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline]
#0: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x4b0 mm/readahead.c:538
1 lock held by syz.8.232/7677:
#0: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
#0: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline]
#0: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x4b0 mm/readahead.c:538
4 locks held by syz-executor/8053:
2 locks held by syz.5.313/8451:
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_super fs/btrfs/super.c:1852 [inline]
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline]
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x47c/0x1930 fs/btrfs/super.c:2121
#1: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:1083 [inline]
#1: ffff888025f71840 (mapping.invalidate_lock){++++}-{4:4}, at: btrfs_read_disk_super+0x1fd/0x530 fs/btrfs/volumes.c:1371
1 lock held by syz.2.315/8464:
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_super fs/btrfs/super.c:1852 [inline]
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline]
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x47c/0x1930 fs/btrfs/super.c:2121
1 lock held by syz.1.317/8486:
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_super fs/btrfs/super.c:1852 [inline]
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline]
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x47c/0x1930 fs/btrfs/super.c:2121
1 lock held by syz.6.318/8495:
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_super fs/btrfs/super.c:1852 [inline]
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline]
#0: ffffffff8e3d8e58 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x47c/0x1930 fs/btrfs/super.c:2121
2 locks held by sed/8527:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5166 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__rcu_read_unlock+0x62/0xe0 kernel/rcu/tree_plugin.h:443
Code: 75 1d 4c 8d b7 c8 04 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 75 66 41 83 3e 00 75 27 43 0f b6 04 3c 84 c0 75 41 8b 03 <3d> 00 00 00 40 73 0f 5b 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc cc
RSP: 0018:ffffc90003c4fc38 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888039106044 RCX: 0000000000000046
RDX: 0000000000000003 RSI: ffffffff8d7bfad2 RDI: ffff888039105b80
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1007220b71 R12: 1ffff11007220c08
R13: 0000000000000000 R14: ffff888039106048 R15: dffffc0000000000
FS: 00007f9df564d880(0000) GS:ffff888126339000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557d42c61008 CR3: 000000003825c000 CR4: 00000000003526f0
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:883 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
kernfs_root+0x1ea/0x230 fs/kernfs/kernfs-internal.h:80
kernfs_active fs/kernfs/dir.c:39 [inline]
kernfs_dir_pos+0x61/0x460 fs/kernfs/dir.c:1839
kernfs_dir_next_pos fs/kernfs/dir.c:1873 [inline]
kernfs_fop_readdir+0x5b2/0x8d0 fs/kernfs/dir.c:1905
iterate_dir+0x3a5/0x580 fs/readdir.c:108
__do_sys_getdents64 fs/readdir.c:412 [inline]
__se_sys_getdents64+0xf1/0x280 fs/readdir.c:397
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9df5784d23
Code: 8b 05 d9 00 10 00 64 c7 00 16 00 00 00 31 c0 eb b0 66 0f 1f 44 00 00 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 a1 00 10 00 f7 d8
RSP: 002b:00007ffd41ae9dc8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00005615c89bfa80 RCX: 00007f9df5784d23
RDX: 0000000000008000 RSI: 00005615c89bfab0 RDI: 000000000000000c
RBP: 00005615c89bfa84 R08: 00007f9df5885ac0 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000293 R12: 00005615c89bfab0
R13: fffffffffffffe68 R14: 0000000000000016 R15: 00007ffd41aea030