syzbot

INFO: task syz.0.17:4361 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:28744 pid: 4361 ppid:  4298 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 rwsem_down_read_slowpath+0x528/0x990 kernel/locking/rwsem.c:1055
 __down_read_common kernel/locking/rwsem.c:1239 [inline]
 __down_read kernel/locking/rwsem.c:1252 [inline]
 down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500
 inode_lock_shared include/linux/fs.h:797 [inline]
 lookup_slow+0x46/0x70 fs/namei.c:1687
 walk_component+0x319/0x460 fs/namei.c:1984
 lookup_last fs/namei.c:2439 [inline]
 path_lookupat+0x169/0x440 fs/namei.c:2463
 filename_lookup+0x1e2/0x4f0 fs/namei.c:2492
 user_path_at_empty+0x40/0x190 fs/namei.c:2891
 user_path_at include/linux/namei.h:57 [inline]
 path_setxattr+0xae/0x280 fs/xattr.c:625
 __do_sys_lsetxattr fs/xattr.c:653 [inline]
 __se_sys_lsetxattr fs/xattr.c:649 [inline]
 __x64_sys_lsetxattr+0xb4/0xd0 fs/xattr.c:649
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe4211e7749
RSP: 002b:00007fe420835038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007fe42143e090 RCX: 00007fe4211e7749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007fe42126bf91 R08: 0000000000000003 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe42143e128 R14: 00007fe42143e090 R15: 00007ffc3c7a8ca8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3944:
 #0: ffff88802bf57098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
3 locks held by syz.0.17/4359:
1 lock held by syz.0.17/4361:
 #0: ffff88806a1902e0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806a1902e0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
3 locks held by syz.1.18/4395:
1 lock held by syz.1.18/4397:
 #0: ffff88806a1f82e0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806a1f82e0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
6 locks held by syz.2.19/4419:
1 lock held by syz.2.19/4421:
 #0: ffff88806a1f9020 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806a1f9020 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
3 locks held by syz.3.20/4444:
1 lock held by syz.3.20/4446:
 #0: ffff88806a1f9d60 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806a1f9d60 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
3 locks held by syz.4.21/4480:
1 lock held by syz.4.21/4483:
 #0: ffff88806a1916c0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806a1916c0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
3 locks held by syz.5.22/4512:
1 lock held by syz.5.22/4514:
 #0: ffff88806a1fa400 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806a1fa400 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
3 locks held by syz.6.23/4542:
1 lock held by syz.6.23/4545:
 #0: ffff88806a192400 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806a192400 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
3 locks held by syz.7.24/4580:
1 lock held by syz.7.24/4582:
 #0: ffff88806a1fb140 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806a1fb140 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 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+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4542 Comm: syz.6.23 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline]
RIP: 0010:kasan_check_range+0xd/0x290 mm/kasan/generic.c:189
Code: c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 00 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 a4 01 00 00 41 57 <41> 56 53 49 89 f8 49 01 f0 0f 82 57 02 00 00 49 89 f8 49 c1 e8 2f
RSP: 0018:ffffc900051d73f8 EFLAGS: 00000202
RAX: ffffffff81a07b01 RBX: ffffea0001502440 RCX: ffffffff81a07b66
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0001502440
RBP: dffffc0000000000 R08: dffffc0000000000 R09: fffff940002a0489
R10: fffff940002a0489 R11: 1ffffd40002a0488 R12: 00fff00000002032
R13: 0000000000000000 R14: ffffea0001502448 R15: ffffea0001502440
FS:  00007fc1e77dd6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f343c18a38 CR3: 000000002bc72000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 PageActive include/linux/page-flags.h:352 [inline]
 mark_page_accessed+0x356/0x12b0 mm/swap.c:414
 __find_get_block+0x257/0x10b0 fs/buffer.c:1314
 __getblk_gfp+0x2c/0xb70 fs/buffer.c:1332
 sb_getblk include/linux/buffer_head.h:361 [inline]
 search_by_key+0x424/0x4390 fs/reiserfs/stree.c:672
 search_by_entry_key+0x32/0x1370 fs/reiserfs/namei.c:125
 reiserfs_find_entry+0xeec/0x18e0 fs/reiserfs/namei.c:322
 reiserfs_lookup+0x1a7/0x420 fs/reiserfs/namei.c:368
 lookup_one_qstr_excl+0x10e/0x240 fs/namei.c:1571
 filename_create+0x21e/0x450 fs/namei.c:3844
 do_mkdirat+0x9d/0x5a0 fs/namei.c:4088
 __do_sys_mkdir fs/namei.c:4118 [inline]
 __se_sys_mkdir fs/namei.c:4116 [inline]
 __x64_sys_mkdir+0x6a/0x80 fs/namei.c:4116
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc1e816e749
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:00007fc1e77dd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007fc1e83c4fa0 RCX: 00007fc1e816e749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000002c0
RBP: 00007fc1e81f2f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc1e83c5038 R14: 00007fc1e83c4fa0 R15: 00007fff6ee94818
 </TASK>