INFO: task syz-executor317:5079 blocked for more than 143 seconds. Not tainted 6.9.0-rc6-syzkaller-00022-g98369dccd2f8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor317 state:D stack:27952 pid:5079 tgid:5078 ppid:5075 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6838 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 bdev_release+0x166/0x710 block/bdev.c:1059 blkdev_release+0x15/0x20 block/fops.c:628 __fput+0x270/0xb80 fs/file_table.c:422 task_work_run+0x14e/0x250 kernel/task_work.c:180 ptrace_notify+0x10e/0x130 kernel/signal.c:2404 ptrace_report_syscall include/linux/ptrace.h:415 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] syscall_exit_work kernel/entry/common.c:173 [inline] syscall_exit_to_user_mode_prepare+0x126/0x260 kernel/entry/common.c:200 __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] syscall_exit_to_user_mode+0x11/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5bf300b7f9 RSP: 002b:00007f5bf2fc3228 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f5bf30933e8 RCX: 00007f5bf300b7f9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f5bf30933e0 R08: 00007f5bf2fc36c0 R09: 00007f5bf2fc36c0 R10: 00007f5bf2fc36c0 R11: 0000000000000246 R12: 00007f5bf30933ec R13: 00007f5bf30601a4 R14: 64626e2f7665642f R15: 00007fff2ee167b8 Showing all locks held in the system: 5 locks held by kworker/u8:1/11: 1 lock held by khungtaskd/29: #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 2 locks held by getty/4827: #0: ffff88802a6c20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201 1 lock held by udevd/5076: #0: ffff88802078b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0x43c/0xe90 block/bdev.c:877 1 lock held by syz-executor317/5079: #0: ffff88802078b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x166/0x710 block/bdev.c:1059 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc6-syzkaller-00022-g98369dccd2f8 #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+0x116/0x1f0 lib/dump_stack.c:114 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf86/0x1240 kernel/hung_task.c:380 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 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 PID: 4514 Comm: klogd Not tainted 6.9.0-rc6-syzkaller-00022-g98369dccd2f8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:__slab_alloc_node mm/slub.c:3639 [inline] RIP: 0010:slab_alloc_node mm/slub.c:3835 [inline] RIP: 0010:__do_kmalloc_node mm/slub.c:3965 [inline] RIP: 0010:__kmalloc_node_track_caller+0x120/0x470 mm/slub.c:3986 Code: 44 24 08 00 00 00 00 4d 85 e4 0f 84 ab 02 00 00 cc 76 01 00 00 48 c7 44 24 20 00 00 00 00 65 48 8b 05 2c 3e 23 7e 49 03 04 24 <48> 8b 50 08 4c 8b 00 48 8b 78 10 4d 85 c0 0f 84 18 02 00 00 48 85 RSP: 0018:ffffc9000333f890 EFLAGS: 00000286 RAX: ffff8880b9543760 RBX: 0000000000482cc0 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000482cc0 RDI: ffff88801504f140 RBP: ffffc9000333f8f0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8f9f4917 R11: 0000000000000001 R12: ffff88801504f140 R13: 0000000000000200 R14: 0000000000482cc0 R15: 00000000ffffffff FS: 00007fd799407380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d208593600 CR3: 000000002c65a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599 __alloc_skb+0x164/0x380 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1313 [inline] alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6504 sock_alloc_send_pskb+0x7f1/0x980 net/core/sock.c:2795 unix_dgram_sendmsg+0x4b9/0x1b10 net/unix/af_unix.c:2019 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x47f/0x4e0 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd7995699b5 Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd41741908 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd7995699b5 RDX: 000000000000008b RSI: 000055aed5b658b0 RDI: 0000000000000003 RBP: 000055aed5b5f2c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007fd7996f7212 R14: 00007ffd41741a08 R15: 0000000000000000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.613 msecs