overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off. ====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/10786 is trying to acquire lock: 00000000eeb00c26 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline] 00000000eeb00c26 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: lookup_slow fs/namei.c:1688 [inline] 00000000eeb00c26 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: walk_component+0x798/0xda0 fs/namei.c:1811 but task is already holding lock: 0000000093210f89 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] 0000000093210f89 (&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: -> #4 (&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 -> #3 (&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 -> #2 (sb_writers#3){.+.+}: sb_start_write include/linux/fs.h:1579 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:360 ovl_xattr_set+0x53/0x600 fs/overlayfs/inode.c:338 __vfs_removexattr+0xf3/0x160 fs/xattr.c:413 __vfs_removexattr_locked+0x15c/0x340 fs/xattr.c:445 vfs_removexattr+0xc1/0x240 fs/xattr.c:466 removexattr+0xc8/0x120 fs/xattr.c:760 path_removexattr+0x147/0x160 fs/xattr.c:774 __do_sys_removexattr fs/xattr.c:788 [inline] __se_sys_removexattr fs/xattr.c:785 [inline] __x64_sys_removexattr+0x55/0x80 fs/xattr.c:785 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&ovl_i_mutex_dir_key[depth]){++++}: inode_lock_shared include/linux/fs.h:758 [inline] lookup_slow fs/namei.c:1688 [inline] lookup_one_len_unlocked+0x111/0x140 fs/namei.c:2573 ovl_lookup_single+0x60/0x920 fs/overlayfs/namei.c:206 ovl_lookup_layer+0x3bd/0x440 fs/overlayfs/namei.c:292 ovl_lookup+0x729/0x1a00 fs/overlayfs/namei.c:903 __lookup_slow+0x246/0x4a0 fs/namei.c:1672 lookup_slow fs/namei.c:1689 [inline] walk_component+0x7ac/0xda0 fs/namei.c:1811 link_path_walk.part.0+0x901/0x1230 fs/namei.c:2142 link_path_walk fs/namei.c:2073 [inline] path_parentat+0x51/0x140 fs/namei.c:2367 filename_parentat+0x198/0x590 fs/namei.c:2389 do_renameat2+0x193/0xc70 fs/namei.c:4547 __do_sys_rename fs/namei.c:4675 [inline] __se_sys_rename fs/namei.c:4673 [inline] __x64_sys_rename+0x5d/0x80 fs/namei.c:4673 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]#2){++++}: down_read+0x36/0x80 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:758 [inline] lookup_slow fs/namei.c:1688 [inline] walk_component+0x798/0xda0 fs/namei.c:1811 link_path_walk.part.0+0x901/0x1230 fs/namei.c:2142 link_path_walk fs/namei.c:2073 [inline] path_openat+0x1db/0x2df0 fs/namei.c:3536 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]#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_dir_key[depth]#2); *** DEADLOCK *** 1 lock held by syz-executor.3/10786: #0: 0000000093210f89 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] #0: 0000000093210f89 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x38c/0x2360 fs/exec.c:1762 stack backtrace: CPU: 0 PID: 10786 Comm: syz-executor.3 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] lookup_slow fs/namei.c:1688 [inline] walk_component+0x798/0xda0 fs/namei.c:1811 link_path_walk.part.0+0x901/0x1230 fs/namei.c:2142 link_path_walk fs/namei.c:2073 [inline] path_openat+0x1db/0x2df0 fs/namei.c:3536 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: 0033:0x7f7b58cfd209 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:00007f7b57672168 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007f7b58e0ff60 RCX: 00007f7b58cfd209 RDX: 0000000020000d80 RSI: 0000000020000cc0 RDI: 0000000020000bc0 RBP: 00007f7b58d57161 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc2d9589df R14: 00007f7b57672300 R15: 0000000000022000 audit: type=1800 audit(1659346409.302:637): pid=10860 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="file0" dev="sda1" ino=14134 res=0 overlayfs: maximum fs stacking depth exceeded overlayfs: maximum fs stacking depth exceeded overlayfs: fs on './file0' does not support file handles, falling back to index=off,nfs_export=off. overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory audit: type=1804 audit(1659346409.332:638): pid=10860 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.5" name="/root/syzkaller-testdir3030848079/syzkaller.e23kNF/887/file0" dev="sda1" ino=14134 res=1 overlayfs: 'file0' not a directory overlayfs: maximum fs stacking depth exceeded overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory IPVS: ftp: loaded support on port[0] = 21 overlayfs: 'file0' not a directory audit: type=1804 audit(1659346409.332:639): pid=10860 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.5" name="/root/syzkaller-testdir3030848079/syzkaller.e23kNF/887/file0" dev="sda1" ino=14134 res=1 overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory audit: type=1800 audit(1659346409.542:640): pid=10937 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="file0" dev="sda1" ino=14167 res=0 overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory audit: type=1804 audit(1659346409.562:641): pid=10937 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.5" name="/root/syzkaller-testdir3030848079/syzkaller.e23kNF/888/file0" dev="sda1" ino=14167 res=1 IPVS: ftp: loaded support on port[0] = 21 overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory audit: type=1804 audit(1659346409.562:642): pid=10937 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.5" name="/root/syzkaller-testdir3030848079/syzkaller.e23kNF/888/file0" dev="sda1" ino=14167 res=1 overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory overlayfs: 'file0' not a directory TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. IPVS: ftp: loaded support on port[0] = 21 netlink: 'syz-executor.5': attribute type 31 has an invalid length. device veth1_macvtap left promiscuous mode TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. nla_parse: 2 callbacks suppressed netlink: 44293 bytes leftover after parsing attributes in process `syz-executor.4'. IPVS: ftp: loaded support on port[0] = 21 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. netlink: 'syz-executor.5': attribute type 31 has an invalid length. netlink: 'syz-executor.5': attribute type 31 has an invalid length. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. IPVS: ftp: loaded support on port[0] = 21 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters.