INFO: task syz.3.740:8922 blocked for more than 144 seconds. Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.740 state:D stack:25472 pid:8922 tgid:8919 ppid:5823 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 sync_bdevs+0x1ae/0x340 block/bdev.c:1246 ksys_sync+0xe2/0x1c0 fs/sync.c:105 __do_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f916a98cd29 RSP: 002b:00007f916b8a8038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f916aba6080 RCX: 00007f916a98cd29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f916aba6080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f916aba6080 R15: 00007ffda2db7388 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e939ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by getty/5580: #0: ffff888031a6e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by udevd/8635: #0: ffff88807a2494c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903 1 lock held by syz.3.740/8922: #0: ffff88807a2494c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246 1 lock held by syz.5.1043/10087: 1 lock held by syz.4.1053/10117: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10137 Comm: syz.1.1059 Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:314 Code: 44 0a 20 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 <65> 48 8b 14 25 c0 d4 03 00 65 8b 05 f0 73 44 7e 25 00 01 ff 00 74 RSP: 0018:ffffc9000334f6c0 EFLAGS: 00000246 RAX: ffffffff89b07cb9 RBX: 0000000000000000 RCX: 0000000000080000 RDX: ffffc9000d364000 RSI: 0000000000000001 RDI: 0000000000000007 RBP: 0000000000000001 R08: ffffffff89b07ccc R09: 1ffffffff2858d1f R10: dffffc0000000000 R11: fffffbfff2858d20 R12: ffff8880242598c0 R13: 0000000000000000 R14: 0000000000000000 R15: ffffc9000334fd10 FS: 00007f7b2643c6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff78bf3000 CR3: 000000003344e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cpu_max_bits_warn include/linux/cpumask.h:135 [inline] cpumask_check include/linux/cpumask.h:142 [inline] cpumask_test_cpu include/linux/cpumask.h:570 [inline] cpu_online include/linux/cpumask.h:1116 [inline] trace_skb_copy_datagram_iovec include/trace/events/skb.h:76 [inline] skb_copy_datagram_iter+0x3c/0x250 net/core/datagram.c:537 skb_copy_datagram_msg include/linux/skbuff.h:4144 [inline] __unix_dgram_recvmsg+0x7e3/0x12f0 net/unix/af_unix.c:2473 sock_recvmsg_nosec+0x18e/0x1d0 net/socket.c:1018 ____sys_recvmsg+0x3cd/0x480 net/socket.c:2786 ___sys_recvmsg net/socket.c:2830 [inline] do_recvmmsg+0x426/0xab0 net/socket.c:2925 __sys_recvmmsg net/socket.c:2999 [inline] __do_sys_recvmmsg net/socket.c:3022 [inline] __se_sys_recvmmsg net/socket.c:3015 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3015 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7b2558cd29 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:00007f7b2643c038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f7b257a6080 RCX: 00007f7b2558cd29 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007f7b2560e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7b257a6080 R15: 00007ffe450956c8