INFO: task syz.3.18:5776 blocked for more than 143 seconds.
      Not tainted 5.15.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.18        state:D stack:14800 pid: 5776 ppid:  3902 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x38a/0x1420 kernel/sched/core.c:6376
 schedule+0x68/0xb0 kernel/sched/core.c:6459
 rwsem_down_write_slowpath+0x2c0/0x610 kernel/locking/rwsem.c:1165
 inode_lock_nested include/linux/fs.h:822 [inline]
 filename_create+0xe4/0x240 fs/namei.c:3835
 do_mkdirat+0x54/0x1e0 fs/namei.c:4080
 __do_sys_mkdirat fs/namei.c:4105 [inline]
 __se_sys_mkdirat fs/namei.c:4103 [inline]
 __x64_sys_mkdirat+0x6b/0x90 fs/namei.c:4103
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x33/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f295f2700b7
RSP: 002b:00007f295ecd0e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f295ecd0ef0 RCX: 00007f295f2700b7
RDX: 00000000000001ff RSI: 0000000020000100 RDI: 00000000ffffff9c
RBP: 0000000020000180 R08: 0000000020000000 R09: 0000000000000000
R10: 0000000020000180 R11: 0000000000000246 R12: 0000000020000100
R13: 00007f295ecd0eb0 R14: 0000000000000000 R15: 0000000020000300
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff845a1d40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x15/0xf7 kernel/locking/lockdep.c:6472
2 locks held by getty/1934:
 #0: ffff888145e8d898 (&tty->ldisc_sem){....}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x60 drivers/tty/tty_ldisc.c:252
 #1: ffffc90003fbf2e8 (&ldata->atomic_read_lock){....}-{3:3}, at: n_tty_read+0x899/0xa20 drivers/tty/n_tty.c:2158
2 locks held by syz.3.18/5758:
2 locks held by syz.3.18/5776:
 #0: ffff888116ef1448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88810eb0c188 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88810eb0c188 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
3 locks held by syz.1.16/5933:
2 locks held by syz.1.16/5962:
 #0: ffff8881174a9448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88810eb0c638 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88810eb0c638 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
3 locks held by syz.6.17/6060:
2 locks held by syz.6.17/6076:
 #0: ffff8881190bc448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88810eb0cae8 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88810eb0cae8 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
2 locks held by syz.0.15/6075:
2 locks held by syz.0.15/6083:
 #0: ffff888118a76448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88811b968188 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88811b968188 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
2 locks held by syz.5.19/6096:
2 locks held by syz.5.19/6102:
 #0: ffff888116e22448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88811b968638 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88811b968638 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
2 locks held by syz.7.20/8116:
2 locks held by syz.7.20/8135:
 #0: ffff88810c0c0448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88811b968ae8 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88811b968ae8 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
3 locks held by syz.8.21/8281:
2 locks held by syz.8.21/8294:
 #0: ffff88810c0c1448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88811b968f98 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88811b968f98 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
2 locks held by syz.2.24/8307:
2 locks held by syz.2.24/8311:
 #0: ffff888117f2a448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88810eb0cf98 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88810eb0cf98 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
3 locks held by syz.9.22/8326:
2 locks held by syz.9.22/8334:
 #0: ffff888117f28448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88810eb0d448 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88810eb0d448 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
2 locks held by syz.4.23/8343:
2 locks held by syz.4.23/8344:
 #0: ffff888110b9a448 (sb_writers#13){....}-{0:0}, at: filename_create+0x91/0x240 fs/namei.c:3828
 #1: ffff88811b969448 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline]
 #1: ffff88811b969448 (&type->i_mutex_dir_key#8/1){....}-{3:3}, at: filename_create+0xe4/0x240 fs/namei.c:3835
1 lock held by syz.3.2600/15338:

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

NMI backtrace for cpu 1
CPU: 1 PID: 26 Comm: khungtaskd Not tainted 5.15.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x8e/0xdd lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x46/0xde lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x139/0x170 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0x7c6/0x810 kernel/hung_task.c:369
 kthread+0x16c/0x1a0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6060 Comm: syz.6.17 Not tainted 5.15.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:205
Code: 89 0c ed 00 64 3a 89 48 89 70 18 5b 5d 41 5c 41 5d c3 48 c7 c0 f4 ff ff ff eb 9a 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <65> 48 8b 14 25 80 af 01 00 65 8b 05 e0 5a d7 7e a9 00 01 ff 00 48
RSP: 0018:ffffc90002563a50 EFLAGS: 00000082
RAX: 0000000000000000 RBX: 0000000000000009 RCX: ffffffff814e7370
RDX: ffff88803ff8edc8 RSI: ffff888110923800 RDI: 0000000000000007
RBP: ffff88803ff8edc8 R08: ffffc90002563ba4 R09: ffff8880198cc800
R10: 0000000000000000 R11: 0000000000000d6e R12: 0000000000000009
R13: 00000000003186d1 R14: ffff888092d68888 R15: 0000000000020175
FS:  00007f48c3f046c0(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200004a9 CR3: 0000000107700000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lookup_bh_lru fs/buffer.c:1277 [inline]
 __find_get_block+0x8a/0x590 fs/buffer.c:1306
 __getblk_gfp fs/buffer.c:1332 [inline]
 __bread_gfp+0x29/0x220 fs/buffer.c:1381
 sb_bread include/linux/buffer_head.h:337 [inline]
 get_branch+0xf3/0x200 fs/sysv/itree.c:101
 get_block+0xb6/0x980 fs/sysv/itree.c:221
 block_read_full_page+0xf8/0x7f0 fs/buffer.c:2290
 do_read_cache_page+0x5cd/0xa60 mm/filemap.c:3473
 read_mapping_page include/linux/pagemap.h:515 [inline]
 dir_get_page fs/sysv/dir.c:58 [inline]
 sysv_find_entry+0x99/0x2c0 fs/sysv/dir.c:146
 sysv_inode_by_name+0x2d/0x140 fs/sysv/dir.c:360
 sysv_lookup fs/sysv/namei.c:38 [inline]
 sysv_lookup+0x4e/0xa0 fs/sysv/namei.c:31
 lookup_one_qstr_excl+0x93/0xd0 fs/namei.c:1563
 filename_create+0xf5/0x240 fs/namei.c:3836
 do_mkdirat+0x54/0x1e0 fs/namei.c:4080
 __do_sys_mkdirat fs/namei.c:4105 [inline]
 __se_sys_mkdirat fs/namei.c:4103 [inline]
 __x64_sys_mkdirat+0x6b/0x90 fs/namei.c:4103
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x33/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f48c4483819
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f48c3f04038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f48c463afa0 RCX: 00007f48c4483819
RDX: 0000000000000000 RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007f48c44f675e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f48c463afa0 R15: 00007ffcfa91b7a8
 </TASK>