====================================================== WARNING: possible circular locking dependency detected 4.19.138-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/23449 is trying to acquire lock: 0000000050927443 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline] 0000000050927443 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: lookup_slow fs/namei.c:1688 [inline] 0000000050927443 (&ovl_i_mutex_dir_key[depth]#2){++++}, at: lookup_one_len_unlocked+0x111/0x140 fs/namei.c:2573 but task is already holding lock: 000000006ca40356 (&ovl_i_mutex_dir_key[depth]#3){.+.+}, at: inode_lock_shared include/linux/fs.h:758 [inline] 000000006ca40356 (&ovl_i_mutex_dir_key[depth]#3){.+.+}, at: do_last fs/namei.c:3326 [inline] 000000006ca40356 (&ovl_i_mutex_dir_key[depth]#3){.+.+}, at: path_openat+0x17ec/0x2df0 fs/namei.c:3537 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&ovl_i_mutex_dir_key[depth]#3){.+.+}: 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:1757 do_execveat_common fs/exec.c:1866 [inline] do_execve+0x35/0x50 fs/exec.c:1883 __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1959 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #3 (&sig->cred_guard_mutex){+.+.}: lock_trace fs/proc/base.c:402 [inline] proc_pid_personality+0x4a/0x170 fs/proc/base.c:2926 proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4be/0x1160 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+0x471/0x630 fs/read_write.c:925 vfs_readv+0xe5/0x150 fs/read_write.c:987 do_preadv fs/read_write.c:1071 [inline] __do_sys_preadv fs/read_write.c:1121 [inline] __se_sys_preadv fs/read_write.c:1116 [inline] __x64_sys_preadv+0x22b/0x310 fs/read_write.c:1116 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&p->lock){+.+.}: seq_read+0x6b/0x1160 fs/seq_file.c:161 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_do_remove+0xf0/0xdb0 fs/overlayfs/dir.c:843 vfs_rmdir.part.0+0x10f/0x3d0 fs/namei.c:3882 vfs_rmdir fs/namei.c:3868 [inline] do_rmdir+0x3fd/0x490 fs/namei.c:3943 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] 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_open+0x698/0x1a20 fs/namei.c:3214 do_last fs/namei.c:3327 [inline] path_openat+0x1804/0x2df0 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:1757 do_execveat_common fs/exec.c:1866 [inline] do_execve+0x35/0x50 fs/exec.c:1883 __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x7c/0xa0 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]#2 --> &sig->cred_guard_mutex --> &ovl_i_mutex_dir_key[depth]#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_mutex_dir_key[depth]#3); lock(&sig->cred_guard_mutex); lock(&ovl_i_mutex_dir_key[depth]#3); lock(&ovl_i_mutex_dir_key[depth]#2); *** DEADLOCK *** 2 locks held by syz-executor.2/23449: #0: 00000000e2c018b7 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1406 [inline] #0: 00000000e2c018b7 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x38c/0x2360 fs/exec.c:1749 #1: 000000006ca40356 (&ovl_i_mutex_dir_key[depth]#3){.+.+}, at: inode_lock_shared include/linux/fs.h:758 [inline] #1: 000000006ca40356 (&ovl_i_mutex_dir_key[depth]#3){.+.+}, at: do_last fs/namei.c:3326 [inline] #1: 000000006ca40356 (&ovl_i_mutex_dir_key[depth]#3){.+.+}, at: path_openat+0x17ec/0x2df0 fs/namei.c:3537 stack backtrace: CPU: 0 PID: 23449 Comm: syz-executor.2 Not tainted 4.19.138-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+0x1fc/0x2fe lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e 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+0x30c9/0x3ff0 kernel/locking/lockdep.c:3415 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3907 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] 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_open+0x698/0x1a20 fs/namei.c:3214 do_last fs/namei.c:3327 [inline] path_openat+0x1804/0x2df0 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:1757 do_execveat_common fs/exec.c:1866 [inline] do_execve+0x35/0x50 fs/exec.c:1883 __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1959 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ce69 Code: 2d b6 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fcdfd836c78 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 0000000000002c80 RCX: 000000000045ce69 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000500 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007fff001bd41f R14: 00007fcdfd8379c0 R15: 000000000118bf2c audit: type=1800 audit(1597039227.982:508): pid=23456 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=18739 res=0 device bond525 entered promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. audit: type=1800 audit(1597039228.442:509): pid=23538 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=18399 res=0 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. (unnamed net_device) (uninitialized): Device ip_vti0 is not bonding slave (unnamed net_device) (uninitialized): option active_slave: invalid value (ip_vti0) audit: type=1800 audit(1597039229.192:510): pid=23668 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=18723 res=0 (unnamed net_device) (uninitialized): Device ip_vti0 is not bonding slave (unnamed net_device) (uninitialized): option active_slave: invalid value (ip_vti0) audit: type=1800 audit(1597039229.652:511): pid=23740 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=18821 res=0 (unnamed net_device) (uninitialized): Device ip_vti0 is not bonding slave audit: type=1800 audit(1597039230.242:512): pid=23805 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=18106 res=0 (unnamed net_device) (uninitialized): option active_slave: invalid value (ip_vti0) audit: type=1800 audit(1597039230.782:513): pid=23836 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=18383 res=0 audit: type=1800 audit(1597039231.322:514): pid=23881 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=18897 res=0 (unnamed net_device) (uninitialized): Device ip_vti0 is not bonding slave (unnamed net_device) (uninitialized): option active_slave: invalid value (ip_vti0) (unnamed net_device) (uninitialized): Device ip_vti0 is not bonding slave (unnamed net_device) (uninitialized): option active_slave: invalid value (ip_vti0) audit: type=1800 audit(1597039231.912:515): pid=23934 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=18773 res=0 audit: type=1800 audit(1597039232.492:516): pid=23989 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=18853 res=0 audit: type=1800 audit(1597039233.002:517): pid=24073 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=18932 res=0 audit: type=1800 audit(1597039233.592:518): pid=24153 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=18980 res=0 device bond532 entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): bond532: link is not ready 8021q: adding VLAN 0 to HW filter on device bond532 audit: type=1800 audit(1597039234.162:519): pid=24189 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=18415 res=0 audit: type=1800 audit(1597039235.282:520): pid=24314 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=19009 res=0 netlink: 4 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.5'. audit: type=1800 audit(1597039236.472:521): pid=24469 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=18446 res=0 IPv6: ADDRCONF(NETDEV_UP): bond535: link is not ready 8021q: adding VLAN 0 to HW filter on device bond535 netlink: 4 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.5'.