audit: type=1800 audit(1659397265.356:117): pid=23581 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="memory.events" dev="sda1" ino=14983 res=0 ====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/23658 is trying to acquire lock: 000000002ed6e7d7 (&ovl_i_mutex_dir_key[depth]){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline] 000000002ed6e7d7 (&ovl_i_mutex_dir_key[depth]){++++}, at: do_last fs/namei.c:3326 [inline] 000000002ed6e7d7 (&ovl_i_mutex_dir_key[depth]){++++}, at: path_openat+0x17ec/0x2df0 fs/namei.c:3537 but task is already holding lock: 000000009ec8ca21 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] 000000009ec8ca21 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x38c/0x2360 fs/exec.c:1762 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&sig->cred_guard_mutex){+.+.}: do_io_accounting fs/proc/base.c:2750 [inline] proc_tgid_io_accounting+0x1cf/0x7f0 fs/proc/base.c:2799 proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4e0/0x11c0 fs/seq_file.c:232 __vfs_read+0xf7/0x750 fs/read_write.c:416 vfs_read+0x194/0x3c0 fs/read_write.c:452 ksys_read+0x12b/0x2a0 fs/read_write.c:579 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&p->lock){+.+.}: seq_read+0x6b/0x11c0 fs/seq_file.c:164 proc_reg_read+0x1bd/0x2d0 fs/proc/inode.c:231 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x471/0x630 fs/read_write.c:925 vfs_readv+0xe5/0x150 fs/read_write.c:987 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x457/0xa00 fs/splice.c:417 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (sb_writers#3){.+.+}: sb_start_write include/linux/fs.h:1579 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:360 ovl_setattr+0xdd/0x920 fs/overlayfs/inode.c:30 notify_change+0x70b/0xfc0 fs/attr.c:334 chown_common+0x4a9/0x550 fs/open.c:651 do_fchownat+0x126/0x1e0 fs/open.c:681 __do_sys_lchown fs/open.c:706 [inline] __se_sys_lchown fs/open.c:704 [inline] __x64_sys_lchown+0x7a/0xc0 fs/open.c:704 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&ovl_i_mutex_dir_key[depth]){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:758 [inline] do_last fs/namei.c:3326 [inline] path_openat+0x17ec/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_open_execat+0x11d/0x5b0 fs/exec.c:853 __do_execve_file+0x1a8b/0x2360 fs/exec.c:1770 do_execveat_common fs/exec.c:1879 [inline] do_execve+0x35/0x50 fs/exec.c:1896 __do_sys_execve fs/exec.c:1977 [inline] __se_sys_execve fs/exec.c:1972 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1972 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &ovl_i_mutex_dir_key[depth] --> &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_dir_key[depth]); *** DEADLOCK *** 1 lock held by syz-executor.1/23658: #0: 000000009ec8ca21 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] #0: 000000009ec8ca21 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x38c/0x2360 fs/exec.c:1762 stack backtrace: CPU: 1 PID: 23658 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:758 [inline] do_last fs/namei.c:3326 [inline] path_openat+0x17ec/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_open_execat+0x11d/0x5b0 fs/exec.c:853 __do_execve_file+0x1a8b/0x2360 fs/exec.c:1770 do_execveat_common fs/exec.c:1879 [inline] do_execve+0x35/0x50 fs/exec.c:1896 __do_sys_execve fs/exec.c:1977 [inline] __se_sys_execve fs/exec.c:1972 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1972 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f362b132209 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3629aa7168 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007f362b244f60 RCX: 00007f362b132209 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000100 RBP: 00007f362b18c161 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffe055411f R14: 00007f3629aa7300 R15: 0000000000022000 overlayfs: overlapping lowerdir path overlayfs: maximum fs stacking depth exceeded overlayfs: maximum fs stacking depth exceeded overlayfs: maximum fs stacking depth exceeded overlayfs: failed to resolve './file1': -2 EXT4-fs (loop3): mounted filesystem without journal. Opts: ,errors=continue UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 512 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off. UDF-fs: Scanning with blocksize 1024 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 2048 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 4096 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 512 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 1024 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 2048 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 4096 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found EXT4-fs (loop3): mounted filesystem without journal. Opts: ,errors=continue UDF-fs: Scanning with blocksize 512 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 1024 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 2048 failed UDF-fs: warning (device loop4): udf_load_vrs: No VRS found UDF-fs: Scanning with blocksize 4096 failed kauditd_printk_skb: 44 callbacks suppressed audit: type=1800 audit(1659397270.437:147): pid=24178 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.1" name="file0" dev="sda1" ino=14054 res=0 audit: type=1804 audit(1659397270.457:148): pid=24178 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir1267497160/syzkaller.GuyCxT/250/file0" dev="sda1" ino=14054 res=1 audit: type=1800 audit(1659397270.787:149): pid=24189 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.4" name="file0" dev="sda1" ino=13972 res=0 audit: type=1804 audit(1659397270.787:150): pid=24183 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.4" name="/root/syzkaller-testdir1748510421/syzkaller.VoQOx3/241/file0" dev="sda1" ino=13972 res=1 audit: type=1800 audit(1659397270.907:151): pid=24196 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="file0" dev="sda1" ino=14210 res=0 audit: type=1804 audit(1659397270.957:152): pid=24196 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir2808439805/syzkaller.p2lthD/210/file0" dev="sda1" ino=14210 res=1 audit: type=1800 audit(1659397271.497:153): pid=24209 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.1" name="file0" dev="sda1" ino=14194 res=0 audit: type=1804 audit(1659397271.547:154): pid=24209 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir1267497160/syzkaller.GuyCxT/251/file0" dev="sda1" ino=14194 res=1 audit: type=1800 audit(1659397272.417:155): pid=24220 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="file0" dev="sda1" ino=13889 res=0 audit: type=1804 audit(1659397272.417:156): pid=24220 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir2808439805/syzkaller.p2lthD/211/file0" dev="sda1" ino=13889 res=1 netlink: 'syz-executor.4': attribute type 1 has an invalid length. IPv6: ADDRCONF(NETDEV_UP): bond1: link is not ready 8021q: adding VLAN 0 to HW filter on device bond1 netlink: 'syz-executor.3': attribute type 1 has an invalid length. IPv6: ADDRCONF(NETDEV_UP): bond1: link is not ready 8021q: adding VLAN 0 to HW filter on device bond1 netlink: 'syz-executor.4': attribute type 1 has an invalid length. netlink: 'syz-executor.4': attribute type 1 has an invalid length. bond2 (uninitialized): Released all slaves overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir overlayfs: filesystem on './bus' not supported as upperdir