====================================================== WARNING: possible circular locking dependency detected 4.19.115-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/22948 is trying to acquire lock: 000000001f34caa4 (&sig->cred_guard_mutex){+.+.}, at: lock_trace+0x45/0xe0 fs/proc/base.c:402 but task is already holding lock: 00000000daae6e3e (&p->lock){+.+.}, at: seq_read+0x6b/0x10f0 fs/seq_file.c:161 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&p->lock){+.+.}: seq_read+0x6b/0x10f0 fs/seq_file.c:161 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 -> #2 (sb_writers#3){.+.+}: sb_start_write include/linux/fs.h:1579 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:360 ovl_do_remove+0xf8/0xd70 fs/overlayfs/dir.c:843 vfs_rmdir fs/namei.c:3882 [inline] vfs_rmdir+0x194/0x460 fs/namei.c:3861 do_rmdir+0x371/0x3e0 fs/namei.c:3943 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] do_last fs/namei.c:3326 [inline] path_openat+0x1d18/0x4200 fs/namei.c:3537 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 -> #0 (&sig->cred_guard_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0xf7/0x1300 kernel/locking/mutex.c:1072 lock_trace+0x45/0xe0 fs/proc/base.c:402 proc_pid_stack+0x12c/0x290 fs/proc/base.c:452 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 other info that might help us debug this: Chain exists of: &sig->cred_guard_mutex --> sb_writers#3 --> &p->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->lock); lock(sb_writers#3); lock(&p->lock); lock(&sig->cred_guard_mutex); *** DEADLOCK *** SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=22956 comm=syz-executor.3 1 lock held by syz-executor.4/22948: #0: 00000000daae6e3e (&p->lock){+.+.}, at: seq_read+0x6b/0x10f0 fs/seq_file.c:161 stack backtrace: CPU: 0 PID: 22948 Comm: syz-executor.4 Not tainted 4.19.115-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:1861 [inline] check_prevs_add kernel/locking/lockdep.c:1974 [inline] validate_chain kernel/locking/lockdep.c:2415 [inline] __lock_acquire+0x2e19/0x49c0 kernel/locking/lockdep.c:3411 lock_acquire+0x170/0x400 kernel/locking/lockdep.c:3903 __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0xf7/0x1300 kernel/locking/mutex.c:1072 CIFS VFS: Malformed UNC in devname. lock_trace+0x45/0xe0 fs/proc/base.c:402 proc_pid_stack+0x12c/0x290 fs/proc/base.c:452 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 RIP: 0033:0x45c889 Code: ad 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f549e815c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007f549e8166d4 RCX: 000000000045c889 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000085c R14: 00000000004cb214 R15: 000000000076bf0c EXT4-fs (loop5): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs: failed to create workqueue EXT4-fs (loop5): mount failed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=22974 comm=syz-executor.3 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=22982 comm=syz-executor.1 CIFS VFS: Malformed UNC in devname. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=23001 comm=syz-executor.3 CIFS VFS: Malformed UNC in devname. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=23011 comm=syz-executor.1 EXT4-fs (loop5): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock CIFS VFS: Malformed UNC in devname. EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=23019 comm=syz-executor.3 EXT4-fs (loop5): ext4_check_descriptors: Inode table for group 0 overlaps superblock CIFS VFS: Malformed UNC in devname. EXT4-fs (loop5): orphan cleanup on readonly fs EXT4-fs error (device loop5): ext4_orphan_get:1257: comm syz-executor.5: bad orphan inode 257 EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue CIFS VFS: Malformed UNC in devname. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=23035 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=23043 comm=syz-executor.3 CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=23064 comm=syz-executor.3 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=23065 comm=syz-executor.1 EXT4-fs (loop5): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs (loop5): orphan cleanup on readonly fs EXT4-fs error (device loop5): ext4_orphan_get:1257: comm syz-executor.5: bad orphan inode 257 EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. EXT4-fs (loop5): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs (loop5): orphan cleanup on readonly fs EXT4-fs error (device loop5): ext4_orphan_get:1257: comm syz-executor.5: bad orphan inode 257 EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue EXT4-fs (loop5): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs (loop5): orphan cleanup on readonly fs EXT4-fs error (device loop5): ext4_orphan_get:1257: comm syz-executor.5: bad orphan inode 257 EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue netlink: 40 bytes leftover after parsing attributes in process `syz-executor.1'. EXT4-fs (loop5): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue netlink: 40 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 40 bytes leftover after parsing attributes in process `syz-executor.1'. EXT4-fs (loop5): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock selinux_nlmsg_perm: 12 callbacks suppressed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=23244 comm=syz-executor.1 EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue cifs_parse_mount_options: 8 callbacks suppressed CIFS VFS: Malformed UNC in devname. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=23256 comm=syz-executor.1 CIFS VFS: Malformed UNC in devname. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=23278 comm=syz-executor.1 EXT4-fs (loop5): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock CIFS VFS: Malformed UNC in devname. EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs (loop5): mounted filesystem without journal. Opts: ,errors=continue CIFS VFS: Malformed UNC in devname. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=23299 comm=syz-executor.1 EXT4-fs (loop5): ext4_check_descriptors: Block bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode bitmap for group 0 overlaps superblock EXT4-fs (loop5): ext4_check_descriptors: Inode table for group 0 overlaps superblock EXT4-fs error (device loop5): ext4_fill_super:4435: inode #2: comm syz-executor.5: iget: root inode unallocated EXT4-fs (loop5): get root inode failed EXT4-fs (loop5): mount failed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=23368 comm=syz-executor.1 CIFS VFS: Device name not specified. CIFS VFS: Malformed UNC in devname. EXT4-fs (loop5): bad geometry: block count 1080 exceeds size of device (1 blocks) SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=23487 comm=syz-executor.1 EXT4-fs (loop5): VFS: Can't find ext4 filesystem EXT4-fs (loop5): VFS: Can't find ext4 filesystem SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=23511 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=23529 comm=syz-executor.1 EXT4-fs (loop5): VFS: Can't find ext4 filesystem EXT4-fs (loop5): VFS: Can't find ext4 filesystem EXT4-fs (loop5): VFS: Can't find ext4 filesystem EXT4-fs (loop5): VFS: Can't find ext4 filesystem EXT4-fs (loop5): VFS: Can't find ext4 filesystem EXT4-fs (loop5): VFS: Can't find ext4 filesystem EXT4-fs (loop5): VFS: Can't find ext4 filesystem