INFO: task syz.3.28:6070 blocked for more[ 260.818595][ T38] INFO: task syz.3.28:6070 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.28 state:D stack:27272 pid:6070 tgid:6057 ppid:5802 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 percpu_rwsem_wait+0x2e6/0x330 kernel/locking/percpu-rwsem.c:164 __percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180 percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1916 [inline] sb_start_write include/linux/fs.h:2052 [inline] quotactl_block fs/quota/quota.c:899 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x83c/0x950 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f210e75efc9 RSP: 002b:00007f210c99d038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f210e9b6090 RCX: 00007f210e75efc9 RDX: 00000000000041c0 RSI: 0000200000000140 RDI: ffffffff80000301 RBP: 00007f210e7e1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f210e9b6128 R14: 00007f210e9b6090 R15: 00007ffd3c86ecb8 Showing all locks held in the system: 6 locks held by ktimers/0/16: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5559: #0: ffff88823bf340a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5797: 1 lock held by syz.3.28/6070: #0: ffff888060f3c480 (sb_writers#19){++++}-{0:0}, at: do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] #0: ffff888060f3c480 (sb_writers#19){++++}-{0:0}, at: do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 2 locks held by syz-executor/6354: 2 locks held by syz.7.301/7975: 3 locks held by udevd/8004: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:___slab_alloc+0x848/0x13f0 mm/slub.c:4533 Code: 83 c7 58 be ff ff ff ff e8 05 73 b0 08 85 c0 0f 84 56 0a 00 00 49 8b 46 10 83 78 28 00 0f 89 f6 0a 00 00 8b 45 40 4a 8b 04 38 <49> 89 06 49 83 46 08 08 48 8b 5d 00 48 83 c3 20 e8 f3 88 b0 08 41 RSP: 0018:ffffc90000157440 EFLAGS: 00000286 RAX: 0000000000000000 RBX: ffffffff91c7fa50 RCX: 3fb143c487bdbf00 RDX: 0000000000000000 RSI: ffffffff8d03e2e6 RDI: ffffffff8b3f5460 RBP: ffff888140ea38c0 R08: 0000000000000000 R09: ffffffff8ac8fb41 R10: dffffc0000000000 R11: fffffbfff1deee6f R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880b8845a30 R15: ffff88805bfd8dc0 FS: 0000000000000000(0000) GS:ffff888126bc6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fda7e719000 CR3: 00000000396cc000 CR4: 00000000003526f0 Call Trace: __slab_alloc+0xc6/0x1f0 mm/slub.c:4755 __slab_alloc_node mm/slub.c:4831 [inline] slab_alloc_node mm/slub.c:5253 [inline] kmem_cache_alloc_node_noprof+0x1ac/0x6e0 mm/slub.c:5317 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 skb_copy+0x188/0x800 net/core/skbuff.c:2125 mac80211_hwsim_tx_frame_no_nl+0xcd3/0x11c0 drivers/net/wireless/virtual/mac80211_hwsim.c:1891 mac80211_hwsim_tx_frame+0x1b5/0x200 drivers/net/wireless/virtual/mac80211_hwsim.c:2258 mac80211_hwsim_beacon_tx+0x3f0/0x860 drivers/net/wireless/virtual/mac80211_hwsim.c:2359 __iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:761 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:797 mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2389 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x552/0xd40 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1858 handle_softirqs+0x22f/0x710 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0xcf/0x190 kernel/softirq.c:1138 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245