====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/5244 is trying to acquire lock: 00000000d33bd54b (&ovl_i_mutex_dir_key[depth]){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline] 00000000d33bd54b (&ovl_i_mutex_dir_key[depth]){++++}, at: lookup_slow fs/namei.c:1688 [inline] 00000000d33bd54b (&ovl_i_mutex_dir_key[depth]){++++}, at: walk_component+0x798/0xda0 fs/namei.c:1811 but task is already holding lock: 00000000a2a76cd7 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] 00000000a2a76cd7 (&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){+.+.}: lock_trace fs/proc/base.c:402 [inline] proc_pid_personality+0x4a/0x170 fs/proc/base.c:2938 proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4e0/0x11c0 fs/seq_file.c:232 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 (&p->lock){+.+.}: seq_read+0x6b/0x11c0 fs/seq_file.c:164 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_create_object+0x96/0x290 fs/overlayfs/dir.c:602 lookup_open+0x893/0x1a20 fs/namei.c:3235 do_last fs/namei.c:3327 [inline] path_openat+0x1094/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 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] 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] --> &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.3/5244: #0: 00000000a2a76cd7 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1419 [inline] #0: 00000000a2a76cd7 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file+0x38c/0x2360 fs/exec.c:1762 stack backtrace: CPU: 0 PID: 5244 Comm: syz-executor.3 Not tainted 4.19.211-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/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: 0033:0x7f4fd7a44049 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:00007f4fd63b9168 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007f4fd7b56f60 RCX: 00007f4fd7a44049 RDX: 0000000020000640 RSI: 0000000020000500 RDI: 0000000020000300 RBP: 00007f4fd7a9e08d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd0a1b1d4f R14: 00007f4fd63b9300 R15: 0000000000022000 ISO 9660 Extensions: Microsoft Joliet Level 3 overlayfs: missing 'workdir' ISO 9660 Extensions: Microsoft Joliet Level 3 overlayfs: missing 'workdir' overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file0': -2 overlayfs: failed to resolve './file1': -2 ovl_get_inode: 15 callbacks suppressed overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: unrecognized mount option "/file1" or missing value overlayfs: unrecognized mount option "workdwardir=./file0" or missing value overlayfs: unrecognized mount option "workdwardir=./file0" or missing value overlayfs: failed to resolve './file0': -2 overlayfs: unrecognized mount option "/file1" or missing value NILFS (loop5): couldn't find nilfs on the device overlayfs: unrecognized mount option "uHAXpperdir=./bus" or missing value NILFS (loop5): couldn't find nilfs on the device kauditd_printk_skb: 59 callbacks suppressed audit: type=1800 audit(1648090511.079:894): pid=5581 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed comm="syz-executor.4" name="/" dev="fuse" ino=0 res=0 NILFS (loop5): couldn't find nilfs on the device overlayfs: unrecognized mount option "uHAXpperdir=./bus" or missing value overlayfs: failed to resolve './f^沄ZofV1ile0lS_A;@(Z?@X=#E^멯xI B': -2 overlayfs: failed to resolve './f^沄ZofV1ile0lS_A;@(Z?@X=#E^멯xI B': -2 overlayfs: unrecognized mount option "uHAXpperdir=./bus" or missing value overlayfs: failed to resolve './file0': -2 overlayfs: failed to resolve './f^沄ZofV1ile0lS_A;@(Z?@X=#E^멯xI B': -2 NILFS (loop2): couldn't find nilfs on the device overlayfs: unrecognized mount option "uppe_kfh=#'rdir=./bus" or missing value overlayfs: failed to resolve './file0': -2 audit: type=1804 audit(1648090512.039:895): pid=5776 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.4" name="/root/syzkaller-testdir2422439050/syzkaller.f2mFwa/1222/file0" dev="sda1" ino=15029 res=1 overlayfs: failed to resolve './file0': -2 overlayfs: unrecognized mount option "udius" or missing value audit: type=1804 audit(1648090512.069:896): pid=5784 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.4" name="/root/syzkaller-testdir2422439050/syzkaller.f2mFwa/1222/file0" dev="sda1" ino=15029 res=1 NILFS (loop2): couldn't find nilfs on the device overlayfs: failed to resolve './file1': -2 NILFS (loop2): couldn't find nilfs on the device overlayfs: unrecognized mount option "wo(Xfile1" or missing value overlayfs: unrecognized mount option "udius" or missing value overlayfs: failed to resolve './file1': -2 NILFS (loop2): couldn't find nilfs on the device overlayfs: failed to resolve './file1': -2 NILFS (loop2): couldn't find nilfs on the device NILFS (loop2): couldn't find nilfs on the device ovl_get_inode: 18 callbacks suppressed overlayfs: failed to get inode (-116) NILFS (loop2): couldn't find nilfs on the device overlayfs: failed to get inode (-116) overlayfs: unrecognized mount option "vorkdir=./file1" or missing value overlayfs: failed to resolve './file0': -2 NILFS (loop2): couldn't find nilfs on the device overlayfs: failed to resolve './file1': -2 overlayfs: unrecognized mount option "vorkdir=./file1" or missing value overlayfs: failed to resolve './file1': -2 overlayfs: unrecognized mount option "vorkdir=./file1" or missing value NILFS (loop2): couldn't find nilfs on the device NILFS (loop2): couldn't find nilfs on the device overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116) overlayfs: unrecognized mount option "w &orkdir5./file1" or missing value audit: type=1800 audit(1648090514.989:897): pid=6067 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed comm="syz-executor.4" name="/" dev="fuse" ino=0 res=0 NILFS (loop2): couldn't find nilfs on the device overlayfs: unrecognized mount option "w &orkdir5./file1" or missing value overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 NILFS (loop2): couldn't find nilfs on the device overlayfs: failed to resolve './file1': -2 overlayfs: failed to resolve './file1': -2 overlayfs: unrecognized mount option "w &orkdir5./file1" or missing value NILFS (loop2): couldn't find nilfs on the device overlayfs: failed to get inode (-116) overlayfs: failed to get inode (-116)