INFO: task syz-executor.4:7396 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-executor.4 state:D stack:26832 pid:7396 tgid:7395 ppid:5538 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5c70 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6828 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6885 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 nbd_start_device_ioctl drivers/block/nbd.c:1464 [inline] __nbd_ioctl drivers/block/nbd.c:1524 [inline] nbd_ioctl+0x312/0xfd0 drivers/block/nbd.c:1564 blkdev_ioctl+0x2f7/0x770 block/ioctl.c:640 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fe3de87dda9 RSP: 002b:00007fe3df5740c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe3de9abf80 RCX: 00007fe3de87dda9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000005 RBP: 00007fe3de8ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fe3de9abf80 R15: 00007ffce270fa08 INFO: task syz-executor.4:7400 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-executor.4 state:D stack:28736 pid:7400 tgid:7395 ppid:5538 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5c70 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6828 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6885 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 bdev_open+0x444/0xe30 block/bdev.c:862 blkdev_open+0x17b/0x1f0 block/fops.c:620 do_dentry_open+0x8da/0x18c0 fs/open.c:955 do_open fs/namei.c:3642 [inline] path_openat+0x1dfb/0x2990 fs/namei.c:3799 do_filp_open+0x1dc/0x430 fs/namei.c:3826 do_sys_openat2+0x17a/0x1e0 fs/open.c:1406 do_sys_open fs/open.c:1421 [inline] __do_sys_openat fs/open.c:1437 [inline] __se_sys_openat fs/open.c:1432 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1432 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fe3de87c9a0 RSP: 002b:00007fe3df552c00 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe3de87c9a0 RDX: 0000000000000000 RSI: 00007fe3df552ca0 RDI: 00000000ffffff9c RBP: 00007fe3df552ca0 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000006e R14: 00007fe3de9ac050 R15: 00007ffce270fa08 INFO: task syz-executor.4:7405 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-executor.4 state:D stack:27792 pid:7405 tgid:7395 ppid:5538 flags:0x00000006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5c70 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6828 blk_mq_freeze_queue_wait+0x146/0x190 block/blk-mq.c:138 nbd_add_socket+0x18c/0x980 drivers/block/nbd.c:1165 __nbd_ioctl drivers/block/nbd.c:1507 [inline] nbd_ioctl+0xa16/0xfd0 drivers/block/nbd.c:1564 blkdev_ioctl+0x2f7/0x770 block/ioctl.c:640 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fe3de87dda9 RSP: 002b:00007fe3df5320c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe3de9ac120 RCX: 00007fe3de87dda9 RDX: 0000000000000003 RSI: 000000000000ab00 RDI: 0000000000000005 RBP: 00007fe3de8ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fe3de9ac120 R15: 00007ffce270fa08 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 3 locks held by kworker/u8:3/50: 2 locks held by getty/4816: #0: ffff88802a5650a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015e02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201 1 lock held by udevd/5073: #0: ffff8880206cb4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0x444/0xe30 block/bdev.c:862 1 lock held by syz-executor.2/5079: 1 lock held by syz-executor.4/7396: #0: ffff8880205df998 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_start_device_ioctl drivers/block/nbd.c:1464 [inline] #0: ffff8880205df998 (&nbd->config_lock){+.+.}-{3:3}, at: __nbd_ioctl drivers/block/nbd.c:1524 [inline] #0: ffff8880205df998 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x312/0xfd0 drivers/block/nbd.c:1564 1 lock held by syz-executor.4/7400: #0: ffff8880206cb4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0x444/0xe30 block/bdev.c:862 1 lock held by syz-executor.4/7405: #0: ffff8880205df998 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x151/0xfd0 drivers/block/nbd.c:1557 ============================================= 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 02/29/2024 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:222 [inline] watchdog+0xf86/0x1210 kernel/hung_task.c:379 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:243 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5079 Comm: syz-executor.2 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x60 kernel/kcov.c:207 Code: c3 cc cc cc cc 66 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 65 48 8b 15 04 db 76 7e <65> 8b 05 05 db 76 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 RSP: 0018:ffffc9000347f5b0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc9000347f690 RCX: 1ffffffff28d0b54 RDX: ffff888075e2bc00 RSI: ffffffff813c973b RDI: ffff888075e2d0c0 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000003 R12: 0000000000000000 R13: fffff5200068fed4 R14: fffff5200068fed3 R15: ffffc9000347f688 FS: 0000555577fc3480(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f93b8779198 CR3: 000000002495e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x14f/0x23a0 arch/x86/kernel/unwind_orc.c:494 __unwind_start+0x5aa/0x880 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xb2/0x170 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:240 [inline] __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kfree+0x129/0x370 mm/slub.c:4390 tomoyo_realpath_from_path+0x1ad/0x720 security/tomoyo/realpath.c:286 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x273/0x450 security/tomoyo/file.c:822 tomoyo_path_unlink+0x92/0xe0 security/tomoyo/tomoyo.c:162 security_path_unlink+0x100/0x170 security/security.c:1851 do_unlinkat+0x55b/0x750 fs/namei.c:4399 __do_sys_unlink fs/namei.c:4450 [inline] __se_sys_unlink fs/namei.c:4448 [inline] __x64_sys_unlink+0xc7/0x110 fs/namei.c:4448 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fa46da7d557 Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcfc5c9d08 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000004412 RCX: 00007fa46da7d557 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffcfc5c9dc0 RBP: 00007ffcfc5c9dc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffcfc5cae80 R13: 00007fa46dac93b9 R14: 0000555577fc3430 R15: 0000000000000005