INFO: task syz-fuzzer:5248 blocked for more than 143 seconds. Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-fuzzer state:D stack:22200 pid:5248 tgid:5063 ppid:5061 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17d3/0x4a20 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6828 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6885 rwsem_down_write_slowpath+0xeeb/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common+0x1af/0x200 kernel/locking/rwsem.c:1306 inode_lock include/linux/fs.h:793 [inline] vfs_unlink+0xe4/0x600 fs/namei.c:4327 do_unlinkat+0x4ae/0x830 fs/namei.c:4402 __do_sys_unlinkat fs/namei.c:4445 [inline] __se_sys_unlinkat fs/namei.c:4438 [inline] __x64_sys_unlinkat+0xce/0xf0 fs/namei.c:4438 do_syscall_64+0xfd/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x40720e RSP: 002b:000000c000bfb638 EFLAGS: 00000202 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000010 RCX: 000000000040720e RDX: 0000000000000000 RSI: 000000c001371160 RDI: 0000000000000010 RBP: 000000c000bfb678 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000116 R13: 000000c000532400 R14: 000000c000122680 R15: 000000c001416700 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4825: #0: ffff88802adfd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 3 locks held by syz-fuzzer/5248: #0: ffff8880290d4420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 #1: ffff88805cd9f200 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:828 [inline] #1: ffff88805cd9f200 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4389 #2: ffff88805a8fb600 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline] #2: ffff88805a8fb600 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: vfs_unlink+0xe4/0x600 fs/namei.c:4327 5 locks held by syz-executor.0/8631: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfb0/0xff0 kernel/hung_task.c:379 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1099 Comm: kworker/u8:6 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: bat_events batadv_purge_orig RIP: 0010:preempt_count_sub+0x32/0x170 kernel/sched/core.c:5898 Code: fb 48 c7 c0 60 d6 4d 94 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 0f b6 04 30 84 c0 0f 85 d0 00 00 00 83 3d fe e9 e8 12 00 <75> 22 65 8b 05 1d e4 9e 7e 89 c1 81 e1 ff ff ff 7f 39 d9 7c 27 81 RSP: 0018:ffffc90000007390 EFLAGS: 00000246 RAX: 0000000000000004 RBX: 0000000000000001 RCX: ffffffff944dd603 RDX: 0000000080000102 RSI: ffffc90000007860 RDI: 0000000000000001 RBP: ffffc90000007480 R08: ffffffff8140ad65 R09: ffffffff8140a8df R10: 0000000000000003 R11: ffff8880223a5a00 R12: ffffc900000078c0 R13: dffffc0000000000 R14: dffffc0000000000 R15: ffffc900000078c8 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f11c726038 CR3: 000000000df32000 CR4: 0000000000350ef0 Call Trace: unwind_next_frame+0x1e65/0x2a00 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3798 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc_node+0x194/0x380 mm/slub.c:3888 kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:577 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:668 __netdev_alloc_skb+0x105/0x560 net/core/skbuff.c:732 netdev_alloc_skb include/linux/skbuff.h:3306 [inline] dev_alloc_skb include/linux/skbuff.h:3319 [inline] __ieee80211_beacon_get+0x998/0x15c0 net/mac80211/tx.c:5466 ieee80211_beacon_get_tim+0xb4/0x320 net/mac80211/tx.c:5588 ieee80211_beacon_get include/net/mac80211.h:5552 [inline] mac80211_hwsim_beacon_tx+0x398/0x7e0 drivers/net/wireless/virtual/mac80211_hwsim.c:2296 __iterate_interfaces+0x225/0x4c0 net/mac80211/util.c:772 ieee80211_iterate_active_interfaces_atomic+0xd8/0x170 net/mac80211/util.c:808 mac80211_hwsim_beacon+0xd4/0x1f0 drivers/net/wireless/virtual/mac80211_hwsim.c:2326 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x597/0xd00 kernel/time/hrtimer.c:1756 hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1773 __do_softirq+0x2be/0x943 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_purge_orig_ref+0x150a/0x1600 net/batman-adv/originator.c:1287 batadv_purge_orig+0x19/0x60 net/batman-adv/originator.c:1300 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa02/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243