====================================================== WARNING: possible circular locking dependency detected 4.14.175-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/29440 is trying to acquire lock: (&ovl_i_mutex_key[depth]#2){+.+.}, at: [] inode_lock include/linux/fs.h:719 [inline] (&ovl_i_mutex_key[depth]#2){+.+.}, at: [] bprm_fill_uid fs/exec.c:1522 [inline] (&ovl_i_mutex_key[depth]#2){+.+.}, at: [] prepare_binprm+0x31a/0x7e0 fs/exec.c:1557 but task is already holding lock: (&sig->cred_guard_mutex){+.+.}, at: [] prepare_bprm_creds+0x51/0x110 fs/exec.c:1389 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&sig->cred_guard_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 lock_trace+0x3f/0xc0 fs/proc/base.c:407 proc_pid_stack+0x10b/0x240 fs/proc/base.c:457 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4d2/0x1160 fs/seq_file.c:237 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3e3/0x5a0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 do_preadv+0x161/0x200 fs/read_write.c:1065 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #2 (&p->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 seq_read+0xba/0x1160 fs/seq_file.c:165 proc_reg_read+0xf2/0x160 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3e3/0x5a0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x41d/0x870 fs/splice.c:416 do_splice_to+0xfb/0x150 fs/splice.c:880 splice_direct_to_actor+0x20a/0x730 fs/splice.c:952 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x469/0xaf0 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #1 (sb_writers#3){.+.+}: percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x1a1/0x2e0 fs/super.c:1363 sb_start_write include/linux/fs.h:1549 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_do_remove+0x65/0xb10 fs/overlayfs/dir.c:759 vfs_unlink+0x27f/0x480 fs/namei.c:4027 do_unlinkat+0x315/0x5d0 fs/namei.c:4092 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (&ovl_i_mutex_key[depth]#2){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 down_write+0x34/0x90 kernel/locking/rwsem.c:54 inode_lock include/linux/fs.h:719 [inline] bprm_fill_uid fs/exec.c:1522 [inline] prepare_binprm+0x31a/0x7e0 fs/exec.c:1557 do_execveat_common.isra.0+0xcc9/0x1c70 fs/exec.c:1783 do_execve fs/exec.c:1847 [inline] SYSC_execve fs/exec.c:1928 [inline] SyS_execve+0x34/0x40 fs/exec.c:1923 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 other info that might help us debug this: Chain exists of: &ovl_i_mutex_key[depth]#2 --> &p->lock --> &sig->cred_guard_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sig->cred_guard_mutex); lock(&p->lock); lock(&sig->cred_guard_mutex); lock(&ovl_i_mutex_key[depth]#2); *** DEADLOCK *** 1 lock held by syz-executor.5/29440: #0: (&sig->cred_guard_mutex){+.+.}, at: [] prepare_bprm_creds+0x51/0x110 fs/exec.c:1389 stack backtrace: CPU: 0 PID: 29440 Comm: syz-executor.5 Not tainted 4.14.175-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 print_circular_bug.isra.0.cold+0x1c4/0x282 kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2cb3/0x4620 kernel/locking/lockdep.c:3487 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 down_write+0x34/0x90 kernel/locking/rwsem.c:54 inode_lock include/linux/fs.h:719 [inline] bprm_fill_uid fs/exec.c:1522 [inline] prepare_binprm+0x31a/0x7e0 fs/exec.c:1557 do_execveat_common.isra.0+0xcc9/0x1c70 fs/exec.c:1783 do_execve fs/exec.c:1847 [inline] SYSC_execve fs/exec.c:1928 [inline] SyS_execve+0x34/0x40 fs/exec.c:1923 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c889 RSP: 002b:00007f4310078c78 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007f43100796d4 RCX: 000000000045c889 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000000a6 R14: 00000000004c33d1 R15: 000000000076bf0c Invalid argument reading file caps for ./bus block nbd0: Receive control failed (result -107) block nbd0: Attempted send on invalid socket block nbd0: shutting down sockets print_req_error: I/O error, dev nbd0, sector 0 buffer_io_error: 2 callbacks suppressed Buffer I/O error on dev nbd0, logical block 0, async page read Buffer I/O error on dev nbd0, logical block 1, async page read jfs: Unrecognized mount option "grxquota" or missing value Buffer I/O error on dev nbd0, logical block 2, async page read Buffer I/O error on dev nbd0, logical block 3, async page read print_req_error: I/O error, dev nbd0, sector 0 Buffer I/O error on dev nbd0, logical block 0, async page read Buffer I/O error on dev nbd0, logical block 1, async page read Buffer I/O error on dev nbd0, logical block 2, async page read Buffer I/O error on dev nbd0, logical block 3, async page read print_req_error: I/O error, dev nbd0, sector 0 Buffer I/O error on dev nbd0, logical block 0, async page read Buffer I/O error on dev nbd0, logical block 1, async page read print_req_error: I/O error, dev nbd0, sector 0 print_req_error: I/O error, dev nbd0, sector 0 jfs: Unrecognized mount option "grxquota" or missing value print_req_error: I/O error, dev nbd0, sector 0 print_req_error: I/O error, dev nbd0, sector 0 print_req_error: I/O error, dev nbd0, sector 0 ldm_validate_partition_table(): Disk read failed. print_req_error: I/O error, dev nbd0, sector 0 print_req_error: I/O error, dev nbd0, sector 0 Dev nbd0: unable to read RDB block 0 nbd0: unable to read partition table block nbd0: Receive control failed (result -107) block nbd0: Attempted send on invalid socket block nbd0: shutting down sockets ldm_validate_partition_table(): Disk read failed. Dev nbd0: unable to read RDB block 0 nbd0: unable to read partition table block nbd0: Receive control failed (result -107) block nbd0: Attempted send on invalid socket block nbd0: shutting down sockets ldm_validate_partition_table(): Disk read failed. Dev nbd0: unable to read RDB block 0 nbd0: unable to read partition table block nbd0: Receive control failed (result -107) block nbd0: Attempted send on invalid socket block nbd0: shutting down sockets ldm_validate_partition_table(): Disk read failed. Dev nbd0: unable to read RDB block 0 nbd0: unable to read partition table block nbd0: Receive control failed (result -107) block nbd0: Attempted send on invalid socket block nbd0: shutting down sockets ldm_validate_partition_table(): Disk read failed. Dev nbd0: unable to read RDB block 0 nbd0: unable to read partition table block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets gfs2: invalid mount option: \*=Q0w6g`^fmA%e\[\; gfs2: can't parse mount arguments block nbd4: Receive control failed (result -107) block nbd0: shutting down sockets block nbd4: shutting down sockets block nbd0: shutting down sockets block nbd0: shutting down sockets FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 29833 Comm: syz-executor.0 Not tainted 4.14.175-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x14b lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x2e9/0x7c0 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:661 [inline] __alloc_workqueue_key+0x114/0xec0 kernel/workqueue.c:3996 nbd_start_device+0x168/0xcb0 drivers/block/nbd.c:1179 nbd_start_device_ioctl drivers/block/nbd.c:1238 [inline] __nbd_ioctl drivers/block/nbd.c:1320 [inline] nbd_ioctl+0x3e8/0xa30 drivers/block/nbd.c:1360 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x91d/0x17d0 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c889 RSP: 002b:00007f8f5cb61c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8f5cb626d4 RCX: 000000000045c889 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 0000000000000401 R14: 00000000004c6a1f R15: 0000000000000000 audit: type=1804 audit(1586451611.237:120): pid=29852 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir659870258/syzkaller.06DxqD/1011/bus" dev="sda1" ino=16389 res=1 block nbd0: Could not allocate knbd recv work queue. block nbd0: shutting down sockets audit: type=1804 audit(1586451611.607:121): pid=29864 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir659870258/syzkaller.06DxqD/1012/bus" dev="sda1" ino=16399 res=1 block nbd0: Receive control failed (result -107) audit: type=1804 audit(1586451611.707:122): pid=29880 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir659870258/syzkaller.06DxqD/1013/bus" dev="sda1" ino=16399 res=1 block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd5: Receive control failed (result -107) block nbd5: shutting down sockets