SELinux: unrecognized netlink message: protocol=6 nlmsg_type=0 sclass=netlink_xfrm_socket pig=5579 comm=syz-executor.4 SELinux: unrecognized netlink message: protocol=6 nlmsg_type=0 sclass=netlink_xfrm_socket pig=5579 comm=syz-executor.4 INFO: task syz-executor.3:2113 blocked for more than 140 seconds. Not tainted 4.9.203-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25016 2113 1 0x00000004 0000000000000083 ffff8801d0a85f00 ffff8801d19bb180 ffff8801db61ffc0 ffff8801d2145f00 ffff8801db61ffd8 ffff8801a201f688 ffffffff8280a79e ffff8801d0a85f00 ffffffff841f6b00 00ff8801a201f5e8 ffff8801db6208b0 Call Trace: [<00000000744edbc6>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<00000000832a1d22>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579 [<00000000ef82571c>] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [<00000000ef82571c>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [<00000000e8ad2879>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 [<000000002f750155>] __blkdev_get+0x268/0xeb0 fs/block_dev.c:1287 [<0000000078e7f0f5>] blkdev_get+0x2e8/0x920 fs/block_dev.c:1424 [<00000000ae950a54>] blkdev_open+0x1aa/0x250 fs/block_dev.c:1579 [<00000000b6cc23af>] do_dentry_open+0x422/0xd20 fs/open.c:791 [<00000000f6d2ba87>] vfs_open+0x105/0x230 fs/open.c:904 [<00000000960b10d0>] do_last fs/namei.c:3457 [inline] [<00000000960b10d0>] path_openat+0xbf5/0x2f60 fs/namei.c:3581 [<00000000c673818a>] do_filp_open+0x1a1/0x280 fs/namei.c:3615 [<00000000e167da9e>] do_sys_open+0x2f0/0x610 fs/open.c:1097 [<00000000f2e69040>] SYSC_open fs/open.c:1115 [inline] [<00000000f2e69040>] SyS_open+0x2d/0x40 fs/open.c:1110 [<00000000a17ecef1>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 [<00000000974d1cfe>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [<00000000f2c8e0e7>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<00000000f2c8e0e7>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<00000000e2723d4e>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4339 2 locks held by getty/2023: #0: (&tty->ldisc_sem){++++++}, at: [<000000003ceb28f2>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+...}, at: [<000000002b41b726>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/2113: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007c24d60d>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<00000000e8ad2879>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.1/4820: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007c24d60d>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<00000000e8ad2879>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.4/5152: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007c24d60d>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<00000000e8ad2879>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.0/5554: #0: (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<00000000b771055b>] lo_ioctl+0x8e/0x1b10 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.+.}, at: [<0000000041dbdb9a>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189 2 locks held by syz-executor.2/5574: #0: (loop_index_mutex){+.+.+.}, at: [<00000000bd95c5b6>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1974 #1: (&lo->lo_ctl_mutex#2){+.+.+.}, at: [<00000000b6bc3f8b>] loop_control_ioctl+0x17f/0x320 drivers/block/loop.c:1988 1 lock held by syz-executor.2/5586: #0: (loop_index_mutex){+.+.+.}, at: [<00000000bd95c5b6>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1974 3 locks held by blkid/5573: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007c24d60d>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (&bdev->bd_mutex/1){+.+...}, at: [<000000007c24d60d>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #2: (loop_index_mutex){+.+.+.}, at: [<00000000e8ad2879>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.5/5590: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000007c24d60d>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<00000000e8ad2879>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.203-syzkaller #0 ffff8801d98d7cc8 ffffffff81b55f6b 0000000000000001 0000000000000000 0000000000000001 ffffffff8109a001 dffffc0000000000 ffff8801d98d7d00 ffffffff81b6120c 0000000000000001 0000000000000000 0000000000000001 Call Trace: [<00000000e98e257e>] __dump_stack lib/dump_stack.c:15 [inline] [<00000000e98e257e>] dump_stack+0xcb/0x130 lib/dump_stack.c:56 [<00000000a04d9af0>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<00000000d16006e2>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<0000000022ba4b18>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<000000003f22cf4c>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<000000003f22cf4c>] check_hung_task kernel/hung_task.c:126 [inline] [<000000003f22cf4c>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<000000003f22cf4c>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<000000002c43dd31>] kthread+0x278/0x310 kernel/kthread.c:211 [<000000000acc1440>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff828198f1