INFO: task syz.3.1794:12741 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1794 state:D stack:23768 pid:12741 tgid:12736 ppid:5962 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
io_schedule+0x7f/0xd0 kernel/sched/core.c:7791
bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
__wait_on_bit_lock+0xec/0x4e0 kernel/sched/wait_bit.c:93
out_of_line_wait_on_bit_lock+0x13b/0x190 kernel/sched/wait_bit.c:120
wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline]
__lock_buffer fs/buffer.c:71 [inline]
lock_buffer include/linux/buffer_head.h:432 [inline]
block_read_full_folio+0x38f/0x830 fs/buffer.c:2439
filemap_read_folio+0x137/0x3b0 mm/filemap.c:2496
do_read_cache_folio+0x358/0x590 mm/filemap.c:4096
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
amiga_partition+0xe0/0x1dd0 block/partitions/amiga.c:53
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x765/0x14c0 block/partitions/core.c:693
loop_reread_partitions drivers/block/loop.c:448 [inline]
loop_set_status+0x9ab/0xe40 drivers/block/loop.c:1277
loop_set_status64 drivers/block/loop.c:1373 [inline]
lo_ioctl+0xc21/0x1fb0 drivers/block/loop.c:1559
blkdev_ioctl+0x5e3/0x740 block/ioctl.c:792
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0918d9aeb9
RSP: 002b:00007f0919c77028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0919015fa0 RCX: 00007f0918d9aeb9
RDX: 00002000000003c0 RSI: 0000000000004c04 RDI: 0000000000000005
RBP: 00007f0918e08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0919016038 R14: 00007f0919015fa0 R15: 00007ffe22744b08
INFO: task syz.3.1794:12749 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1794 state:D stack:22936 pid:12749 tgid:12736 ppid:5962 task_flags:0x440140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
io_schedule+0x7f/0xd0 kernel/sched/core.c:7791
folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1170 [inline]
__find_get_block_slow fs/buffer.c:205 [inline]
find_get_block_common+0x23c/0xe60 fs/buffer.c:1408
bdev_getblk+0x53/0x6e0 include/linux/gfp.h:-1
__getblk include/linux/buffer_head.h:380 [inline]
sb_getblk include/linux/buffer_head.h:386 [inline]
__ext4_get_inode_loc+0x7d8/0xfa0 fs/ext4/inode.c:4860
ext4_get_inode_loc fs/ext4/inode.c:4963 [inline]
ext4_reserve_inode_write+0x18b/0x360 fs/ext4/inode.c:6287
__ext4_mark_inode_dirty+0x14b/0x6e0 fs/ext4/inode.c:6465
ext4_ext_insert_extent+0x2062/0x4b50 fs/ext4/extents.c:2192
ext4_ext_map_blocks+0x19d1/0x6b80 fs/ext4/extents.c:4404
ext4_map_create_blocks fs/ext4/inode.c:613 [inline]
ext4_map_blocks+0x8da/0x1830 fs/ext4/inode.c:816
ext4_getblk+0x1ca/0x780 fs/ext4/inode.c:984
ext4_bread+0x2a/0x180 fs/ext4/inode.c:1047
ext4_quota_write+0x239/0x580 fs/ext4/super.c:7350
write_blk fs/quota/quota_tree.c:70 [inline]
get_free_dqblk+0x368/0x720 fs/quota/quota_tree.c:136
do_insert_tree+0x256/0x11d0 fs/quota/quota_tree.c:347
do_insert_tree+0x9d7/0x11d0 fs/quota/quota_tree.c:402
do_insert_tree+0x9b2/0x11d0 fs/quota/quota_tree.c:402
do_insert_tree+0x9b2/0x11d0 fs/quota/quota_tree.c:402
dq_insert_tree fs/quota/quota_tree.c:432 [inline]
qtree_write_dquot+0x4b1/0x5e0 fs/quota/quota_tree.c:451
v2_write_dquot+0x183/0x260 fs/quota/quota_v2.c:372
dquot_acquire+0x328/0x620 fs/quota/dquot.c:473
ext4_acquire_dquot+0x2e9/0x4c0 fs/ext4/super.c:6982
dqget+0x7b1/0xf10 fs/quota/dquot.c:980
__dquot_initialize+0x3ba/0xd30 fs/quota/dquot.c:1508
ext4_xattr_set+0xdb/0x340 fs/ext4/xattr.c:2543
__vfs_setxattr+0x43c/0x480 fs/xattr.c:200
__vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234
vfs_setxattr+0x16a/0x2e0 fs/xattr.c:321
do_setxattr fs/xattr.c:636 [inline]
filename_setxattr+0x281/0x630 fs/xattr.c:665
path_setxattrat+0x3f3/0x430 fs/xattr.c:713
__do_sys_lsetxattr fs/xattr.c:754 [inline]
__se_sys_lsetxattr fs/xattr.c:750 [inline]
__x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0918d9aeb9
RSP: 002b:00007f0919c56028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f0919016090 RCX: 00007f0918d9aeb9
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000200000000180
RBP: 00007f0918e08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0919016128 R14: 00007f0919016090 R15: 00007ffe22744b08
Showing all locks held in the system:
1 lock held by khungtaskd/32:
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by udevd/5187:
#0:
ffff8881423cc358
(&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
#1:
ffff8881423cb448
(
&lo->lo_mutex
){+.+.}-{4:4}, at: lo_open+0x4f/0xd0 drivers/block/loop.c:1721
2 locks held by getty/5574:
#0: ffff88814e76c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5970:
#0: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:956
1 lock held by udevd/10512:
#0: ffff8881423cc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by udevd/10515:
#0: ffff888148c4e3a8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline]
#0: ffff888148c4e3a8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: blkdev_read_iter+0x2f8/0x440 block/fops.c:855
1 lock held by syz.3.1794/12741:
#0: ffff8880247da358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_reread_partitions drivers/block/loop.c:447 [inline]
#0: ffff8880247da358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_set_status+0x986/0xe40 drivers/block/loop.c:1277
5 locks held by syz.3.1794/12749:
#0: ffff888031f7e420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888060996420 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff888060996420 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: vfs_setxattr+0x143/0x2e0 fs/xattr.c:320
#2: ffff88805edd7228 (&dquot->dq_lock){+.+.}-{4:4}, at: dquot_acquire+0x67/0x620 fs/quota/dquot.c:461
#3: ffff888031f7e208 (&s->s_dquot.dqio_sem){++++}-{4:4}, at: v2_write_dquot+0xab/0x260 fs/quota/quota_v2.c:367
#4: ffff888060990c10 (&ei->i_data_sem/2){++++}-{4:4}, at: ext4_map_blocks+0x7d7/0x1830 fs/ext4/inode.c:815
2 locks held by ext4lazyinit/15775:
#0: ffff88805aa420e0 (&type->s_umount_key#31){++++}-{4:4}, at: ext4_lazyinit_thread+0x1b7/0x1830 fs/ext4/super.c:3818
#1: ffff88805aa42420 (sb_writers#4){.+.+}-{0:0}, at: kthread+0x726/0x8b0 kernel/kthread.c:463
3 locks held by syz.1.3370/18614:
#0: ffff8881423cb448 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0xc3/0xe40 drivers/block/loop.c:1235
#1: ffff888142392680 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:954 [inline]
#1: ffff888142392680 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: loop_set_status+0x310/0xe40 drivers/block/loop.c:1251
#2: ffff8881423926b8 (&q->q_usage_counter(queue)#2){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:954 [inline]
#2: ffff8881423926b8 (&q->q_usage_counter(queue)#2){+.+.}-{0:0}, at: loop_set_status+0x310/0xe40 drivers/block/loop.c:1251
4 locks held by syz.1.3370/18624:
#0: ffff88805aa42420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88807863a0c0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff88807863a0c0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: vfs_setxattr+0x143/0x2e0 fs/xattr.c:320
#2: ffff8880785a2968 (&dquot->dq_lock){+.+.}-{4:4}, at: dquot_acquire+0x67/0x620 fs/quota/dquot.c:461
#3: ffff88805aa42208 (&s->s_dquot.dqio_sem){++++}-{4:4}, at: v2_read_dquot+0x50/0x1d0 fs/quota/quota_v2.c:342
3 locks held by syz.0.3371/18615:
#0: ffff8881423c8448 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0xc3/0xe40 drivers/block/loop.c:1235
#1: ffff888142391cf8 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:954 [inline]
#1: ffff888142391cf8 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: loop_set_status+0x310/0xe40 drivers/block/loop.c:1251
#2: ffff888142391d30 (&q->q_usage_counter(queue)){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:954 [inline]
#2: ffff888142391d30 (&q->q_usage_counter(queue)){+.+.}-{0:0}, at: loop_set_status+0x310/0xe40 drivers/block/loop.c:1251
4 locks held by syz.0.3371/18626:
#0: ffff88803381c420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff8880786920c0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff8880786920c0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: vfs_setxattr+0x143/0x2e0 fs/xattr.c:320
#2: ffff8880785a3ca8 (&dquot->dq_lock){+.+.}-{4:4}, at: dquot_acquire+0x67/0x620 fs/quota/dquot.c:461
#3: ffff88803381c208 (&s->s_dquot.dqio_sem){++++}-{4:4}, at: v2_read_dquot+0x50/0x1d0 fs/quota/quota_v2.c:342
3 locks held by syz.4.3374/18631:
#0: ffff8880247dc448 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0xc3/0xe40 drivers/block/loop.c:1235
#1: ffff888142394318 (&q->q_usage_counter(io)#21){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:954 [inline]
#1: ffff888142394318 (&q->q_usage_counter(io)#21){++++}-{0:0}, at: loop_set_status+0x310/0xe40 drivers/block/loop.c:1251
#2: ffff888142394350 (&q->q_usage_counter(queue)#5){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:954 [inline]
#2: ffff888142394350 (&q->q_usage_counter(queue)#5){+.+.}-{0:0}, at: loop_set_status+0x310/0xe40 drivers/block/loop.c:1251
4 locks held by syz.4.3374/18633:
#0: ffff88805e0e8420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88807863e420 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff88807863e420 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: vfs_setxattr+0x143/0x2e0 fs/xattr.c:320
#2: ffff8880785a33e8 (&dquot->dq_lock){+.+.}-{4:4}, at: dquot_acquire+0x67/0x620 fs/quota/dquot.c:461
#3: ffff88805e0e8208 (&s->s_dquot.dqio_sem){++++}-{4:4}, at: v2_read_dquot+0x50/0x1d0 fs/quota/quota_v2.c:342
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18624 Comm: syz.1.3370 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 ae ae 92 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 4f fe fa fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 65 75 de fb cc 44 89 f9 80 e1 07
RSP: 0018:ffffc9000ce6ebf0 EFLAGS: 00000002
RAX: 1ffffffff3467000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffffff9a338530 R08: ffff8881482f0237 R09: 1ffff1102905e046
R10: dffffc0000000000 R11: ffffffff8531cb20 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9a3382a0 R15: 0000000000000000
FS: 00007fc4d59d56c0(0000) GS:ffff8881256f3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0ae19e8600 CR3: 00000000527fe000 CR4: 0000000000350ef0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:1961
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x1348/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3129 [inline]
console_flush_one_record kernel/printk/printk.c:3215 [inline]
console_flush_all+0x718/0xb20 kernel/printk/printk.c:3289
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3359
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2426
_printk+0xdd/0x130 kernel/printk/printk.c:2451
__quota_error+0x1a6/0x1d0 fs/quota/dquot.c:148
write_blk fs/quota/quota_tree.c:73 [inline]
get_free_dqblk+0x3cd/0x720 fs/quota/quota_tree.c:136
do_insert_tree+0x256/0x11d0 fs/quota/quota_tree.c:347
do_insert_tree+0x9d7/0x11d0 fs/quota/quota_tree.c:402
dq_insert_tree fs/quota/quota_tree.c:432 [inline]
qtree_write_dquot+0x4b1/0x5e0 fs/quota/quota_tree.c:451
v2_write_dquot+0x183/0x260 fs/quota/quota_v2.c:372
dquot_acquire+0x328/0x620 fs/quota/dquot.c:473
ext4_acquire_dquot+0x2e9/0x4c0 fs/ext4/super.c:6982
dqget+0x7b1/0xf10 fs/quota/dquot.c:980
__dquot_initialize+0x3ba/0xd30 fs/quota/dquot.c:1508
ext4_xattr_set+0xdb/0x340 fs/ext4/xattr.c:2543
__vfs_setxattr+0x43c/0x480 fs/xattr.c:200
__vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234
vfs_setxattr+0x16a/0x2e0 fs/xattr.c:321
do_setxattr fs/xattr.c:636 [inline]
filename_setxattr+0x281/0x630 fs/xattr.c:665
path_setxattrat+0x3f3/0x430 fs/xattr.c:713
__do_sys_lsetxattr fs/xattr.c:754 [inline]
__se_sys_lsetxattr fs/xattr.c:750 [inline]
__x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc4d639aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc4d59d5028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007fc4d6616090 RCX: 00007fc4d639aeb9
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000200000000180
RBP: 00007fc4d6408c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc4d6616128 R14: 00007fc4d6616090 R15: 00007ffed7e83f48