====================================================== WARNING: possible circular locking dependency detected 4.14.166-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/23129 is trying to acquire lock: (&sig->cred_guard_mutex){+.+.}, at: [] do_io_accounting+0x1d6/0x7b0 fs/proc/base.c:2726 but task is already holding lock: (&p->lock){+.+.}, at: [] seq_read+0xc1/0x1280 fs/seq_file.c:165 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&p->lock){+.+.}: lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 seq_read+0xc1/0x1280 fs/seq_file.c:165 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3e2/0x5b0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x421/0x870 fs/splice.c:416 do_splice_to+0x105/0x170 fs/splice.c:880 splice_direct_to_actor+0x222/0x7b0 fs/splice.c:952 do_splice_direct+0x18d/0x230 fs/splice.c:1061 do_sendfile+0x4db/0xbd0 fs/read_write.c:1441 ntfs: (device loop1): parse_options(): Option utf8 is no longer supported, using option nls=utf8. Please use option nls=utf8 in the future and make sure utf8 is compiled either as a module or into the kernel. SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0x102/0x110 fs/read_write.c:1488 ntfs: (device loop1): parse_options(): Unrecognized mount option . do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #2 (sb_writers#4){.+.+}: lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x1ae/0x2f0 fs/super.c:1363 sb_start_write include/linux/fs.h:1548 [inline] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:25 ovl_create_object+0x79/0x1e0 fs/overlayfs/dir.c:538 ovl_create+0x28/0x30 fs/overlayfs/dir.c:563 lookup_open+0x11a6/0x1860 fs/namei.c:3240 do_last fs/namei.c:3331 [inline] path_openat+0xfca/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1084 SYSC_open fs/open.c:1102 [inline] SyS_open fs/open.c:1097 [inline] SYSC_creat fs/open.c:1142 [inline] SyS_creat+0x27/0x30 fs/open.c:1140 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #1 (&ovl_i_mutex_dir_key[depth]){++++}: lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 down_read+0x3b/0xb0 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:728 [inline] do_last fs/namei.c:3330 [inline] path_openat+0x191c/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_open_execat+0xe7/0x4a0 fs/exec.c:849 do_execveat_common.isra.0+0x6d5/0x1dd0 fs/exec.c:1740 do_execve fs/exec.c:1847 [inline] SYSC_execve fs/exec.c:1928 [inline] SyS_execve+0x39/0x50 fs/exec.c:1923 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (&sig->cred_guard_mutex){+.+.}: check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2cb3/0x4620 kernel/locking/lockdep.c:3487 lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 mutex_lock_killable_nested+0x16/0x20 kernel/locking/mutex.c:923 do_io_accounting+0x1d6/0x7b0 fs/proc/base.c:2726 proc_tgid_io_accounting+0x23/0x30 fs/proc/base.c:2775 proc_single_show+0xf0/0x160 fs/proc/base.c:761 seq_read+0x51a/0x1280 fs/seq_file.c:237 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3e2/0x5b0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x421/0x870 fs/splice.c:416 do_splice_to+0x105/0x170 fs/splice.c:880 splice_direct_to_actor+0x222/0x7b0 fs/splice.c:952 do_splice_direct+0x18d/0x230 fs/splice.c:1061 do_sendfile+0x4db/0xbd0 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0x102/0x110 fs/read_write.c:1488 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 other info that might help us debug this: Chain exists of: &sig->cred_guard_mutex --> sb_writers#4 --> &p->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->lock); lock(sb_writers#4); lock(&p->lock); lock(&sig->cred_guard_mutex); *** DEADLOCK *** 1 lock held by syz-executor.0/23129: #0: (&p->lock){+.+.}, at: [] seq_read+0xc1/0x1280 fs/seq_file.c:165 stack backtrace: CPU: 0 PID: 23129 Comm: syz-executor.0 Not tainted 4.14.166-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2cb3/0x4620 kernel/locking/lockdep.c:3487 lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 mutex_lock_killable_nested+0x16/0x20 kernel/locking/mutex.c:923 do_io_accounting+0x1d6/0x7b0 fs/proc/base.c:2726 proc_tgid_io_accounting+0x23/0x30 fs/proc/base.c:2775 proc_single_show+0xf0/0x160 fs/proc/base.c:761 seq_read+0x51a/0x1280 fs/seq_file.c:237 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3e2/0x5b0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x421/0x870 fs/splice.c:416 do_splice_to+0x105/0x170 fs/splice.c:880 splice_direct_to_actor+0x222/0x7b0 fs/splice.c:952 do_splice_direct+0x18d/0x230 fs/splice.c:1061 do_sendfile+0x4db/0xbd0 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0x102/0x110 fs/read_write.c:1488 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45b349 RSP: 002b:00007f760beadc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f760beae6d4 RCX: 000000000045b349 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008a6 R14: 00000000004ca018 R15: 000000000075bf2c bridge0: port 2(bridge_slave_1) entered disabled state bridge0: port 1(bridge_slave_0) entered disabled state hfsplus: unable to find HFS+ superblock ntfs: (device loop1): parse_options(): Option utf8 is no longer supported, using option nls=utf8. Please use option nls=utf8 in the future and make sure utf8 is compiled either as a module or into the kernel. ntfs: (device loop1): parse_options(): Unrecognized mount option . device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device hsr_slave_1 left promiscuous mode device hsr_slave_0 left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed bond0 (unregistering): Releasing backup interface bond_slave_1 bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves audit: type=1400 audit(1579516788.537:155): avc: denied { map } for pid=23178 comm="syz-executor.0" path="/dev/swradio0" dev="devtmpfs" ino=17558 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:device_t:s0 tclass=chr_file permissive=1 ntfs: (device loop1): parse_options(): Option utf8 is no longer supported, using option nls=utf8. Please use option nls=utf8 in the future and make sure utf8 is compiled either as a module or into the kernel. ntfs: (device loop1): parse_options(): Unrecognized mount option . IPVS: ftp: loaded support on port[0] = 21 chnl_net:caif_netlink_parms(): no params data found bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered disabled state device bridge_slave_0 entered promiscuous mode bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_1 entered promiscuous mode bond0: Enslaving bond_slave_0 as an active interface with an up link bond0: Enslaving bond_slave_1 as an active interface with an up link IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready team0: Port device team_slave_0 added IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready team0: Port device team_slave_1 added batman_adv: batadv0: Adding interface: batadv_slave_0 batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active batman_adv: batadv0: Adding interface: batadv_slave_1 batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. ntfs: (device loop1): parse_options(): Option utf8 is no longer supported, using option nls=utf8. Please use option nls=utf8 in the future and make sure utf8 is compiled either as a module or into the kernel. ntfs: (device loop1): parse_options(): Unrecognized mount option . batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready hfsplus: unable to find HFS+ superblock device hsr_slave_0 entered promiscuous mode device hsr_slave_1 entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready 8021q: adding VLAN 0 to HW filter on device bond0 IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready 8021q: adding VLAN 0 to HW filter on device team0 IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready IPv6: ADDRCONF(NETDEV_UP): vxcan0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready 8021q: adding VLAN 0 to HW filter on device batadv0 IPv6: ADDRCONF(NETDEV_UP): veth0_virt_wifi: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_UP): veth0_vlan: link is not ready IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready IPv6: ADDRCONF(NETDEV_UP): vlan1: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready device veth0_vlan entered promiscuous mode device veth1_vlan entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): macvlan0: link is not ready IPv6: ADDRCONF(NETDEV_UP): macvlan1: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready device veth0_macvtap entered promiscuous mode device veth1_macvtap entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! IPv6: ADDRCONF(NETDEV_UP): batadv_slave_0: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_0 IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_1 IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready bridge0: port 2(bridge_slave_1) entered disabled state bridge0: port 1(bridge_slave_0) entered disabled state batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 ntfs: (device loop1): parse_options(): Option utf8 is no longer supported, using option nls=utf8. Please use option nls=utf8 in the future and make sure utf8 is compiled either as a module or into the kernel. ntfs: (device loop1): parse_options(): Unrecognized mount option . hfsplus: unable to find HFS+ superblock overlayfs: workdir and upperdir must be separate subtrees overlayfs: workdir and upperdir must be separate subtrees overlayfs: workdir and upperdir must be separate subtrees batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_1 device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device hsr_slave_1 left promiscuous mode device hsr_slave_0 left promiscuous mode