INFO: task syz.4.1268:12313 blocked for more than 143 seconds.
Tainted: G U 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1268 state:D stack:26120 pid:12313 tgid:12301 ppid:8588 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
io_schedule+0xbf/0x130 kernel/sched/core.c:7742
folio_wait_bit_common+0x3d6/0x9e0 mm/filemap.c:1317
folio_wait_writeback+0x3c/0x90 mm/page-writeback.c:3149
__filemap_fdatawait_range+0x11f/0x200 mm/filemap.c:539
file_write_and_wait_range+0x101/0x140 mm/filemap.c:798
ext4_sync_file+0x310/0xf10 fs/ext4/fsync.c:154
vfs_fsync_range+0x136/0x220 fs/sync.c:187
__do_sys_msync+0x3cb/0x5c0 mm/msync.c:96
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5bdc78e969
RSP: 002b:00007f5bdd58b038 EFLAGS: 00000246 ORIG_RAX: 000000000000001a
RAX: ffffffffffffffda RBX: 00007f5bdc9b6240 RCX: 00007f5bdc78e969
RDX: 0000000400000004 RSI: 01800000ff010000 RDI: 000000001ffff000
RBP: 00007f5bdc810ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5bdc9b6240 R15: 00007ffeab6aec78
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
6 locks held by kworker/u8:15/6441:
#0: ffff888021a81148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000b79fd18 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff88814e03e0e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:562
#3: ffff88814e040b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x1b2/0x820 mm/page-writeback.c:2656
#4: ffff888034542950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444
#5: ffff88807d700cb0 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x355/0x1390 fs/ext4/inode.c:705
2 locks held by getty/10775:
#0: ffff88814d4010a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900041432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
3 locks held by syz.2.1276/12339:
#0: ffff88814e03e420 (sb_writers#4){.+.+}-{0:0}, at: madvise_remove mm/madvise.c:1034 [inline]
#0: ffff88814e03e420 (sb_writers#4){.+.+}-{0:0}, at: madvise_vma_behavior+0x1a75/0x1d50 mm/madvise.c:1263
#1: ffff88807d700e20 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#1: ffff88807d700e20 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: ext4_fallocate+0x111/0x3810 fs/ext4/extents.c:4737
#2: ffff88807d700fc0 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:912 [inline]
#2: ffff88807d700fc0 (mapping.invalidate_lock#2){++++}-{4:4}, at: ext4_fallocate+0x1bc/0x3810 fs/ext4/extents.c:4759
2 locks held by syz.2.1276/12340:
#0: ffff88814e03e420 (sb_writers#4){.+.+}-{0:0}, at: madvise_remove mm/madvise.c:1034 [inline]
#0: ffff88814e03e420 (sb_writers#4){.+.+}-{0:0}, at: madvise_vma_behavior+0x1a75/0x1d50 mm/madvise.c:1263
#1: ffff88807d700e20 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#1: ffff88807d700e20 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: ext4_fallocate+0x111/0x3810 fs/ext4/extents.c:4737
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/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+0xf70/0x12c0 kernel/hung_task.c:437
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245