audit: type=1804 audit(1616588694.991:14146): pid=31654 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir713921517/syzkaller.NSe02o/46/bus" dev="sda1" ino=14401 res=1 ====================================================== WARNING: possible circular locking dependency detected 4.14.227-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/31679 is trying to acquire lock: (&sig->cred_guard_mutex){+.+.}, at: [] lock_trace fs/proc/base.c:407 [inline] (&sig->cred_guard_mutex){+.+.}, at: [] proc_pid_syscall+0xa7/0x2a0 fs/proc/base.c:639 but task is already holding lock: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1120 fs/seq_file.c:165 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&p->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 seq_read+0xba/0x1120 fs/seq_file.c:165 proc_reg_read+0xee/0x1a0 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+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x418/0x910 fs/splice.c:416 do_splice_to+0xfb/0x140 fs/splice.c:880 splice_direct_to_actor+0x207/0x730 fs/splice.c:952 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x47f/0xb30 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+0x46/0xbb -> #3 (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+0x64/0x260 fs/super.c:1342 sb_start_write include/linux/fs.h:1549 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_do_remove+0x67/0xb90 fs/overlayfs/dir.c:759 vfs_rmdir.part.0+0x144/0x390 fs/namei.c:3908 vfs_rmdir fs/namei.c:3893 [inline] do_rmdir+0x334/0x3c0 fs/namei.c:3968 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #2 (&ovl_i_mutex_dir_key[depth]#2){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:729 [inline] lookup_slow+0x129/0x400 fs/namei.c:1674 lookup_one_len_unlocked+0x3a0/0x410 fs/namei.c:2595 ovl_lookup_single+0x33/0x6d0 fs/overlayfs/namei.c:208 ovl_lookup_layer+0x2ef/0x3d0 fs/overlayfs/namei.c:265 ovl_lookup+0x5d9/0x1120 fs/overlayfs/namei.c:670 lookup_slow+0x20a/0x400 fs/namei.c:1696 walk_component+0x6a1/0xbc0 fs/namei.c:1825 link_path_walk+0x823/0x10a0 fs/namei.c:2154 path_parentat+0x41/0x120 fs/namei.c:2398 filename_parentat+0x176/0x520 fs/namei.c:2420 SYSC_renameat2 fs/namei.c:4562 [inline] SyS_renameat2+0x159/0xad0 fs/namei.c:4533 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (&ovl_i_mutex_dir_key[depth]#3){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:729 [inline] do_last fs/namei.c:3333 [inline] path_openat+0x149b/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_open_execat+0xd3/0x450 fs/exec.c:849 do_execveat_common+0x711/0x1f30 fs/exec.c:1755 do_execve fs/exec.c:1860 [inline] SYSC_execve fs/exec.c:1941 [inline] SyS_execve+0x3b/0x50 fs/exec.c:1936 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&sig->cred_guard_mutex){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 lock_trace fs/proc/base.c:407 [inline] proc_pid_syscall+0xa7/0x2a0 fs/proc/base.c:639 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4cf/0x1120 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+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_preadv fs/read_write.c:1065 [inline] SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x15a/0x200 fs/read_write.c:1110 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: &sig->cred_guard_mutex --> sb_writers#3 --> &p->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->lock); lock(sb_writers#3); lock(&p->lock); lock(&sig->cred_guard_mutex); *** DEADLOCK *** 1 lock held by syz-executor.2/31679: #0: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1120 fs/seq_file.c:165 stack backtrace: CPU: 0 PID: 31679 Comm: syz-executor.2 Not tainted 4.14.227-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+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 lock_trace fs/proc/base.c:407 [inline] proc_pid_syscall+0xa7/0x2a0 fs/proc/base.c:639 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4cf/0x1120 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+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_preadv fs/read_write.c:1065 [inline] SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x15a/0x200 fs/read_write.c:1110 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007fd450295188 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 00000000000001a1 RSI: 00000000200017c0 RDI: 0000000000000005 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffcd228351f R14: 00007fd450295300 R15: 0000000000022000 Bluetooth: hci4 command 0x0405 tx timeout loop4: p1 < > p2 p3 < p5 p6 > p4 loop4: p2 size 1073741824 extends beyond EOD, truncated loop4: p5 size 1073741824 extends beyond EOD, truncated loop4: p1 < > p2 p3 < p5 p6 > p4 loop4: p2 size 1073741824 extends beyond EOD, truncated loop4: p5 size 1073741824 extends beyond EOD, truncated loop4: p1 < > p2 p3 < p5 p6 > p4 loop4: p2 size 1073741824 extends beyond EOD, truncated loop4: p5 size 1073741824 extends beyond EOD, truncated loop4: p1 < > p2 p3 < p5 p6 > p4 loop4: p2 size 1073741824 extends beyond EOD, truncated loop4: p5 size 1073741824 extends beyond EOD, truncated nla_parse: 6 callbacks suppressed netlink: 4 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.1'. kauditd_printk_skb: 1 callbacks suppressed audit: type=1800 audit(1616588700.452:14148): pid=32163 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="file0" dev="sda1" ino=14785 res=0 audit: type=1804 audit(1616588700.492:14149): pid=32163 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir294131304/syzkaller.lzlj9z/57/file0" dev="sda1" ino=14785 res=1 audit: type=1800 audit(1616588701.012:14150): pid=32237 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="file0" dev="sda1" ino=14315 res=0 audit: type=1804 audit(1616588701.062:14151): pid=32237 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir294131304/syzkaller.lzlj9z/58/file0" dev="sda1" ino=14315 res=1 audit: type=1800 audit(1616588701.142:14152): pid=32246 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.0" name="file0" dev="sda1" ino=14609 res=0 audit: type=1804 audit(1616588701.452:14153): pid=32246 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir996539835/syzkaller.xheJ34/82/file0" dev="sda1" ino=14609 res=1 audit: type=1800 audit(1616588701.562:14154): pid=32298 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="file0" dev="sda1" ino=14657 res=0 audit: type=1804 audit(1616588701.672:14155): pid=32298 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir294131304/syzkaller.lzlj9z/59/file0" dev="sda1" ino=14657 res=1 audit: type=1800 audit(1616588701.712:14156): pid=32319 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.0" name="file0" dev="sda1" ino=14417 res=0 audit: type=1804 audit(1616588701.712:14157): pid=32319 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir996539835/syzkaller.xheJ34/83/file0" dev="sda1" ino=14417 res=1 netlink: 4 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.5'.