INFO: task syz.2.796:13815 blocked for more than 143 seconds.
Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.796 state:D stack:25408 pid:13815 tgid:13777 ppid:12335 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:867 [inline]
vfs_unlink+0xf2/0x650 fs/namei.c:4568
do_unlinkat+0x350/0x560 fs/namei.c:4643
__do_sys_unlink fs/namei.c:4689 [inline]
__se_sys_unlink fs/namei.c:4687 [inline]
__x64_sys_unlink+0x47/0x50 fs/namei.c:4687
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc9e7b8e969
RSP: 002b:00007fc9e8945038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007fc9e7db6080 RCX: 00007fc9e7b8e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000280
RBP: 00007fc9e7c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc9e7db6080 R15: 00007ffdfe8d0fd8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
3 locks held by kworker/u8:8/3515:
5 locks held by udevd/5189:
#0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
#1: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
#2: ffff8880229c00d0 (&lockref->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2: ffff8880229c00d0 (&lockref->lock){+.+.}-{3:3}, at: __dentry_kill+0x2cf/0x660 fs/dcache.c:671
#3: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#3: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#3: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: is_bpf_text_address+0x26/0x2b0 kernel/bpf/core.c:772
#4: ffff8880598af270 (&lockref->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
#4: ffff8880598af270 (&lockref->lock){+.+.}-{3:3}, at: fast_dput+0xdd/0x430 fs/dcache.c:818
2 locks held by getty/5570:
#0: ffff88814d5510a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/8604:
#0: ffffffff8e638bb0 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#0: ffffffff8e638bb0 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#0: ffffffff8e638bb0 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1108 [inline]
#0: ffffffff8e638bb0 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_check_open_permission+0x16a/0x3b0 security/tomoyo/file.c:767
3 locks held by syz.2.796/13815:
#0: ffff88803b27c420 (sb_writers#26){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff888055264d38 (&sb->s_type->i_mutex_key#21/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline]
#1: ffff888055264d38 (&sb->s_type->i_mutex_key#21/1){+.+.}-{4:4}, at: do_unlinkat+0x1bf/0x560 fs/namei.c:4630
#2: ffff8880552e1078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#2: ffff8880552e1078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: vfs_unlink+0xf2/0x650 fs/namei.c:4568
5 locks held by syz.2.796/13817:
#0: ffff88803b27c420 (sb_writers#26){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff8880552e1078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#1: ffff8880552e1078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: do_truncate+0x186/0x220 fs/open.c:63
#2: ffff888049700a70 (&c->snapshot_create_lock){.+.+}-{4:4}, at: bch2_truncate+0xeb/0x200 fs/bcachefs/io_misc.c:295
#3: ffff888049704228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#3: ffff888049704228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#3: ffff888049704228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3202
#4: ffff888049726590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179
2 locks held by bch-copygc/loop/13810:
3 locks held by syz.5.1047/16201:
#0: ffff888088b80940 (&c->sb_lock){+.+.}-{4:4}, at: bch2_fs_alloc fs/bcachefs/super.c:819 [inline]
#0: ffff888088b80940 (&c->sb_lock){+.+.}-{4:4}, at: bch2_fs_open+0x12e6/0x27e0 fs/bcachefs/super.c:2197
#1: ffff888088b84860 (&c->mark_lock){++++}-{0:0}, at: bch2_sb_replicas_to_cpu_replicas+0x117/0x1a0 fs/bcachefs/replicas.c:600
#2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998
4 locks held by syz.8.1048/16205:
3 locks held by syz.3.1044/16219:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16219 Comm: syz.3.1044 Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 2e 4d 89 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 6f 1c e9 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900049c6910 EFLAGS: 00000002
RAX: 1ffffffff3362f00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffffff99b17c10 R08: ffff888023e40237 R09: 1ffff110047c8046
R10: dffffc0000000000 R11: ffffffff85367060 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99b17980 R15: 0000000000000000
FS: 00007fd7f1e4e6c0(0000) GS:ffff888126200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd38022088 CR3: 0000000059772000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:137 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
wait_for_lsr+0x19e/0x2f0 drivers/tty/serial/8250/8250_port.c:2098
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline]
serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456
console_emit_next_record kernel/printk/printk.c:3138 [inline]
console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
_printk+0xcf/0x120 kernel/printk/printk.c:2475
set_capacity_and_notify+0x208/0x2d0 block/genhd.c:93
loop_set_size+0x44/0xb0 drivers/block/loop.c:210
loop_configure+0xa0a/0xe60 drivers/block/loop.c:1044
lo_ioctl+0x87e/0x22e0 drivers/block/loop.c:-1
blkdev_ioctl+0x5a5/0x6d0 block/ioctl.c:704
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd7f0f8e56b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007fd7f1e4ddc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fd7f0f8e56b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000054ee
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fd7f1e4def0 R14: 00007fd7f1e4deb0 R15: 00007fd7e6800000