syzbot

INFO: task syz.0.17:4309 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:27792 pid: 4309 ppid:  4294 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 d_wait_lookup+0x190/0x260 fs/dcache.c:2571
 d_alloc_parallel+0xa19/0x1330 fs/dcache.c:2653
 __lookup_slow+0x134/0x410 fs/namei.c:1656
 lookup_slow+0x53/0x70 fs/namei.c:1688
 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+0x214/0x540 fs/namei.c:2492
 user_path_at_empty+0x40/0x190 fs/namei.c:2891
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x107/0x500 fs/stat.c:221
 vfs_fstatat fs/stat.c:243 [inline]
 __do_sys_newfstatat fs/stat.c:411 [inline]
 __se_sys_newfstatat fs/stat.c:405 [inline]
 __x64_sys_newfstatat+0x15f/0x200 fs/stat.c:405
 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: 0033:0x7f5491b8b819
RSP: 002b:00007f54911cc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007f5491e05090 RCX: 00007f5491b8b819
RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f5491c21c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5491e05128 R14: 00007f5491e05090 R15: 00007ffea2fbdc78
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:3/300:
2 locks held by getty/3943:
 #0: ffff88814cde2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
2 locks held by syz.0.17/4308:
1 lock held by syz.0.17/4309:
 #0: ffff888068d70168 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff888068d70168 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
3 locks held by syz.1.18/4325:
1 lock held by syz.1.18/4326:
 #0: ffff888068d70690 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff888068d70690 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
2 locks held by syz.2.19/4349:
1 lock held by syz.2.19/4350:
 #0: ffff8880365bc168 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff8880365bc168 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
2 locks held by syz.3.20/4369:
1 lock held by syz.3.20/4370:
 #0: ffff8880365bc690 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff8880365bc690 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
2 locks held by syz.4.21/4392:
1 lock held by syz.4.21/4393:
 #0: ffff8880365bcbb8 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff8880365bcbb8 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
2 locks held by syz.5.22/4423:
1 lock held by syz.5.22/4424:
 #0: ffff8880365bd0e0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff8880365bd0e0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
2 locks held by syz.6.23/4447:
1 lock held by syz.6.23/4448:
 #0: ffff888068d70bb8 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff888068d70bb8 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687
2 locks held by syz.7.24/4470:
1 lock held by syz.7.24/4471:
 #0: ffff8880365bd608 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff8880365bd608 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4222 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:deref_stack_reg+0xd0/0x120 arch/x86/kernel/unwind_orc.c:360
Code: 74 05 e8 b3 01 89 00 49 8b 77 28 49 8d 4f 20 4c 89 f7 4c 89 fa e8 e0 55 f5 ff 85 c0 74 04 31 c0 eb 26 4c 89 f7 e8 90 07 00 00 <49> 89 c6 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 f7
RSP: 0018:ffffc90002e7ee70 EFLAGS: 00000202
RAX: ffffc90002e7f2b8 RBX: ffffc90002e7efa8 RCX: 0000000000000001
RDX: ffffc90002e7efa8 RSI: ffffc90002e7f090 RDI: ffffc90002e7f090
RBP: ffffc90002e80000 R08: ffffc90002e7efc7 R09: ffffc90002e7efb8
R10: dffffc0000000000 R11: fffff520005cfdf9 R12: dffffc0000000000
R13: ffffc90002e78000 R14: ffffc90002e7f090 R15: ffffc90002e7ef68
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558e14d66168 CR3: 00000001431a4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 unwind_next_frame+0x115d/0x1d90 arch/x86/kernel/unwind_orc.c:-1
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 kvfree_call_rcu+0x105/0x7d0 kernel/rcu/tree.c:3600
 cfg80211_update_known_bss+0x178/0xa20 net/wireless/scan.c:-1
 cfg80211_bss_update+0x15f/0x2250 net/wireless/scan.c:1836
 cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2555 [inline]
 cfg80211_inform_bss_frame_data+0x89f/0x1fc0 net/wireless/scan.c:2588
 ieee80211_bss_info_update+0x6be/0xa70 net/mac80211/scan.c:190
 ieee80211_rx_bss_info net/mac80211/ibss.c:1123 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1614 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x1700/0x2ab0 net/mac80211/ibss.c:1643
 ieee80211_iface_process_skb net/mac80211/iface.c:1459 [inline]
 ieee80211_iface_work+0x70e/0xc60 net/mac80211/iface.c:1513
 cfg80211_wiphy_work+0x221/0x260 net/wireless/core.c:433
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>