====================================================== WARNING: possible circular locking dependency detected IPv6: ADDRCONF(NETDEV_UP): veth463: link is not ready 4.19.123-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/15433 is trying to acquire lock: 0000000002c51922 (&ovl_i_mutex_dir_key[depth]){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline] 0000000002c51922 (&ovl_i_mutex_dir_key[depth]){++++}, at: lookup_slow+0x43/0x70 fs/namei.c:1688 but task is already holding lock: 00000000460bf709 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds+0x51/0x120 fs/exec.c:1404 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: IPv6: ADDRCONF(NETDEV_UP): veth541: link is not ready -> #3 (&sig->cred_guard_mutex){+.+.}: lock_trace+0x45/0xe0 fs/proc/base.c:402 proc_pid_personality+0x17/0xc0 fs/proc/base.c:2926 proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4b9/0x10f0 fs/seq_file.c:229 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x46b/0x640 fs/read_write.c:925 vfs_readv+0xf0/0x160 fs/read_write.c:987 do_preadv+0x1b6/0x270 fs/read_write.c:1071 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&p->lock){+.+.}: seq_read+0x6b/0x10f0 fs/seq_file.c:161 proc_reg_read+0x1bd/0x280 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+0x46b/0x640 fs/read_write.c:925 vfs_readv+0xf0/0x160 fs/read_write.c:987 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x478/0x970 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+0x1a8/0x270 fs/splice.c:1068 do_sendfile+0x549/0xc10 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64 fs/read_write.c:1494 [inline] __x64_sys_sendfile64+0x1cc/0x210 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/0x950 fs/overlayfs/inode.c:30 notify_change+0xad7/0xfb0 fs/attr.c:334 chown_common+0x4a9/0x550 fs/open.c:651 do_fchownat+0x126/0x1e0 fs/open.c:681 __do_sys_chown fs/open.c:701 [inline] __se_sys_chown fs/open.c:699 [inline] __x64_sys_chown+0x77/0xb0 fs/open.c:699 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+0x37/0xb0 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:758 [inline] lookup_slow+0x43/0x70 fs/namei.c:1688 walk_component+0x70a/0x1ee0 fs/namei.c:1811 link_path_walk.part.0+0x8fd/0x1210 fs/namei.c:2142 link_path_walk fs/namei.c:2073 [inline] path_openat+0x1ed/0x4200 fs/namei.c:3536 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_open_execat+0x124/0x5b0 fs/exec.c:853 __do_execve_file.isra.0+0x1577/0x2110 fs/exec.c:1755 do_execveat_common fs/exec.c:1866 [inline] do_execve fs/exec.c:1883 [inline] __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x8a/0xb0 fs/exec.c:1959 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.3/15433: #0: 00000000460bf709 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds+0x51/0x120 fs/exec.c:1404 stack backtrace: CPU: 0 PID: 15433 Comm: syz-executor.3 Not tainted 4.19.123-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_circular_bug.isra.0.cold+0x1c4/0x282 kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1865 [inline] check_prevs_add kernel/locking/lockdep.c:1978 [inline] validate_chain kernel/locking/lockdep.c:2419 [inline] __lock_acquire+0x2e19/0x49c0 kernel/locking/lockdep.c:3415 lock_acquire+0x170/0x400 kernel/locking/lockdep.c:3907 down_read+0x37/0xb0 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:758 [inline] lookup_slow+0x43/0x70 fs/namei.c:1688 walk_component+0x70a/0x1ee0 fs/namei.c:1811 link_path_walk.part.0+0x8fd/0x1210 fs/namei.c:2142 link_path_walk fs/namei.c:2073 [inline] path_openat+0x1ed/0x4200 fs/namei.c:3536 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_open_execat+0x124/0x5b0 fs/exec.c:853 __do_execve_file.isra.0+0x1577/0x2110 fs/exec.c:1755 do_execveat_common fs/exec.c:1866 [inline] do_execve fs/exec.c:1883 [inline] __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x8a/0xb0 fs/exec.c:1959 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca29 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f297d516c78 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00000000004db840 RCX: 000000000045ca29 RDX: 0000000020000540 RSI: 0000000020000480 RDI: 0000000020000140 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000000a8 R14: 00000000004c35ac R15: 00007f297d5176d4 loop5: p1 < > p2 p3 < p5 p6 > p4 loop5: p2 size 1073741824 extends beyond EOD, truncated loop5: p5 size 1073741824 extends beyond EOD, truncated IPv6: ADDRCONF(NETDEV_UP): veth543: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth465: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth467: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth545: link is not ready loop5: p1 < > p2 p3 < p5 p6 > p4 loop5: p2 size 1073741824 extends beyond EOD, truncated loop5: p5 size 1073741824 extends beyond EOD, truncated overlayfs: overlapping lowerdir path IPv6: ADDRCONF(NETDEV_UP): veth547: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth469: link is not ready overlayfs: overlapping lowerdir path IPv6: ADDRCONF(NETDEV_UP): veth549: link is not ready overlayfs: overlapping lowerdir path IPv6: ADDRCONF(NETDEV_UP): veth551: link is not ready overlayfs: failed to resolve 'niqe0_+ @BY6)-W jH?ytt <LB%5ϼFUGgpPjmY>S֖qqTQH줠_T~J2C;5HN': -2 overlayfs: failed to resolve 'niqe0_+ @BY6)-W jH?ytt <LB%5ϼFUGgpPjmY>S֖qqTQH줠_T~J2C;5HN': -2 loop5: p1 < > p2 p3 < p5 p6 > p4 loop5: p2 size 1073741824 extends beyond EOD, truncated loop5: p5 size 1073741824 extends beyond EOD, truncated IPv6: ADDRCONF(NETDEV_UP): veth553: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth471: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth555: link is not ready nla_parse: 24 callbacks suppressed netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. IPv6: ADDRCONF(NETDEV_UP): veth473: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. IPv6: ADDRCONF(NETDEV_UP): veth557: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. loop5: p1 < > p2 p3 < p5 p6 > p4 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. loop5: p2 size 1073741824 extends beyond EOD, truncated loop5: p5 size 1073741824 extends beyond EOD, truncated IPv6: ADDRCONF(NETDEV_UP): veth475: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. IPv6: ADDRCONF(NETDEV_UP): veth559: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. overlayfs: overlapping lowerdir path IPv6: ADDRCONF(NETDEV_UP): veth477: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth561: link is not ready overlayfs: invalid redirect ((null)) overlayfs: overlapping lowerdir path overlayfs: overlapping lowerdir path loop5: p1 < > p2 p3 < p5 p6 > p4 loop5: p2 size 1073741824 extends beyond EOD, truncated IPv6: ADDRCONF(NETDEV_UP): veth563: link is not ready loop5: p5 size 1073741824 extends beyond EOD, truncated overlayfs: invalid redirect ((null)) IPv6: ADDRCONF(NETDEV_UP): veth479: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth565: link is not ready overlayfs: invalid redirect ((null)) overlayfs: overlapping lowerdir path IPv6: ADDRCONF(NETDEV_UP): veth567: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth481: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth569: link is not ready loop5: p1 < > p2 p3 < p5 p6 > p4 loop5: p2 size 1073741824 extends beyond EOD, truncated IPv6: ADDRCONF(NETDEV_UP): veth483: link is not ready loop5: p5 size 1073741824 extends beyond EOD, truncated overlayfs: overlapping lowerdir path IPv6: ADDRCONF(NETDEV_UP): veth571: link is not ready overlayfs: overlapping lowerdir path IPv6: ADDRCONF(NETDEV_UP): veth485: link is not ready overlayfs: overlapping lowerdir path IPv6: ADDRCONF(NETDEV_UP): veth573: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth575: link is not ready loop5: p1 < > p2 p3 < p5 p6 > p4 loop5: p2 size 1073741824 extends beyond EOD, truncated loop5: p5 size 1073741824 extends beyond EOD, truncated overlayfs: overlapping lowerdir path IPv6: ADDRCONF(NETDEV_UP): veth577: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth487: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth579: link is not ready overlayfs: overlapping lowerdir path overlayfs: unrecognized mount option "lowl5`o%72n!GѼ]/w^`521Z^;6 ZZb֓Ikvh(=Y`1V{"<"Ob&#\W Rwi7ѯ" or missing value IPv6: ADDRCONF(NETDEV_UP): veth489: link is not ready overlayfs: unrecognized mount option "lowl5`o%72n!GѼ]/w^`521Z^;6 ZZb֓Ikvh(=Y`1V{"<"Ob&#\W Rwi7ѯ" or missing value IPv6: ADDRCONF(NETDEV_UP): veth581: link is not ready overlayfs: overlapping lowerdir path overlayfs: unrecognized mount option "lowerdirF eC!vDj%];QѢp@DR(]96':"b=:# p2 p3 < p5 p6 > p4 loop5: p2 size 1073741824 extends beyond EOD, truncated loop5: p5 size 1073741824 extends beyond EOD, truncated IPv6: ADDRCONF(NETDEV_UP): veth491: link is not ready overlayfs: unrecognized mount option "lowerd" or missing value IPv6: ADDRCONF(NETDEV_UP): veth583: link is not ready overlayfs: unrecognized mount option "lowerd" or missing value nla_parse: 33 callbacks suppressed netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. IPv6: ADDRCONF(NETDEV_UP): veth585: link is not ready overlayfs: unrecognized mount option "" or missing value netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. IPv6: ADDRCONF(NETDEV_UP): veth493: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. IPv6: ADDRCONF(NETDEV_UP): veth587: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. loop5: p1 < > p2 p3 < p5 p6 > p4 loop5: p2 size 1073741824 extends beyond EOD, truncated loop5: p5 size 1073741824 extends beyond EOD, truncated netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. IPv6: ADDRCONF(NETDEV_UP): veth495: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. IPv6: ADDRCONF(NETDEV_UP): veth589: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. IPv6: ADDRCONF(NETDEV_UP): veth591: link is not ready netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. IPv6: ADDRCONF(NETDEV_UP): veth593: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth497: link is not ready overlayfs: missing 'lowerdir' overlayfs: missing 'lowerdir'