====================================================== WARNING: possible circular locking dependency detected 4.14.173-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/14028 is trying to acquire lock: (&sig->cred_guard_mutex){+.+.}, at: [] lock_trace+0x3f/0xc0 fs/proc/base.c:407 but task is already holding lock: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1160 fs/seq_file.c:165 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&p->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 seq_read+0xba/0x1160 fs/seq_file.c:165 proc_reg_read+0xf2/0x160 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3e3/0x5a0 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+0x41d/0x870 fs/splice.c:416 do_splice_to+0xfb/0x150 fs/splice.c:880 splice_direct_to_actor+0x20a/0x730 fs/splice.c:952 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x469/0xaf0 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #2 (sb_writers#4){.+.+}: 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+0x1a1/0x2e0 fs/super.c:1363 sb_start_write include/linux/fs.h:1548 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:386 ovl_xattr_set+0x4d/0x270 fs/overlayfs/inode.c:214 __vfs_setxattr+0xdc/0x130 fs/xattr.c:150 __vfs_setxattr_noperm+0xfd/0x3c0 fs/xattr.c:181 vfs_setxattr+0xba/0xe0 fs/xattr.c:224 setxattr+0x1a9/0x300 fs/xattr.c:453 path_setxattr+0x118/0x130 fs/xattr.c:472 SYSC_setxattr fs/xattr.c:487 [inline] SyS_setxattr+0x36/0x50 fs/xattr.c:483 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #1 (&ovl_i_mutex_dir_key[depth]){++++}: down_read+0x37/0xa0 kernel/locking/rwsem.c:24 inode_lock_shared include/linux/fs.h:728 [inline] do_last fs/namei.c:3333 [inline] path_openat+0x185a/0x3c50 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_open_execat+0xda/0x430 fs/exec.c:849 do_execveat_common.isra.0+0x694/0x1c70 fs/exec.c:1740 do_execve fs/exec.c:1847 [inline] SYSC_execve fs/exec.c:1928 [inline] SyS_execve+0x34/0x40 fs/exec.c:1923 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (&sig->cred_guard_mutex){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 lock_trace+0x3f/0xc0 fs/proc/base.c:407 proc_pid_stack+0x10b/0x240 fs/proc/base.c:457 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4d2/0x1160 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+0x3e3/0x5a0 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+0x41d/0x870 fs/splice.c:416 do_splice_to+0xfb/0x150 fs/splice.c:880 splice_direct_to_actor+0x20a/0x730 fs/splice.c:952 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x469/0xaf0 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 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 *** 2 locks held by syz-executor.1/14028: #0: (sb_writers#4){.+.+}, at: [] file_start_write include/linux/fs.h:2707 [inline] #0: (sb_writers#4){.+.+}, at: [] do_sendfile+0x865/0xaf0 fs/read_write.c:1440 #1: (&p->lock){+.+.}, at: [] seq_read+0xba/0x1160 fs/seq_file.c:165 stack backtrace: CPU: 1 PID: 14028 Comm: syz-executor.1 Not tainted 4.14.173-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+0x13e/0x194 lib/dump_stack.c:58 print_circular_bug.isra.0.cold+0x1c4/0x282 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+0x170/0x3f0 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 lock_trace+0x3f/0xc0 fs/proc/base.c:407 proc_pid_stack+0x10b/0x240 fs/proc/base.c:457 proc_single_show+0xe7/0x150 fs/proc/base.c:761 seq_read+0x4d2/0x1160 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+0x3e3/0x5a0 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+0x41d/0x870 fs/splice.c:416 do_splice_to+0xfb/0x150 fs/splice.c:880 splice_direct_to_actor+0x20a/0x730 fs/splice.c:952 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x469/0xaf0 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c849 RSP: 002b:00007fadeaf5bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fadeaf5c6d4 RCX: 000000000045c849 RDX: 0000000000000000 RSI: 000000000000000c RDI: 000000000000000d RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000401 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d1 R14: 00000000004cb761 R15: 000000000076bf0c XFS (loop5): Mounting V4 Filesystem XFS (loop5): totally zeroed log XFS (loop5): failed to read root inode selinux_nlmsg_perm: 151 callbacks suppressed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=8962 sclass=netlink_route_socket pig=14106 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14114 comm=syz-executor.2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=8962 sclass=netlink_route_socket pig=14115 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=51 sclass=netlink_route_socket pig=14122 comm=syz-executor.2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14114 comm=syz-executor.2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=51 sclass=netlink_route_socket pig=14129 comm=syz-executor.2 bridge0: port 1(bridge_slave_0) entered disabled state IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready 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 bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state ieee80211 phy29: Selected rate control algorithm 'minstrel_ht' hub 9-0:1.0: USB hub found hub 9-0:1.0: 8 ports detected ieee80211 phy29: hwaddr 02:00:00:00:1d:00 registered ieee80211 phy30: Selected rate control algorithm 'minstrel_ht' ieee80211 phy30: hwaddr 02:00:00:00:1e:00 registered audit: type=1804 audit(1584394271.292:12968): pid=14172 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/211/bus" dev="sda1" ino=17528 res=1 Dev loop5: unable to read RDB block 1 loop5: unable to read partition table loop5: partition table beyond EOD, truncated loop_reread_partitions: partition scan of loop5 () failed (rc=-5) Dev loop5: unable to read RDB block 1 loop5: unable to read partition table loop5: partition table beyond EOD, truncated loop_reread_partitions: partition scan of loop5 () failed (rc=-5) audit: type=1804 audit(1584394272.122:12969): pid=14173 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="ToMToU" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/211/bus" dev="sda1" ino=17528 res=1 audit: type=1804 audit(1584394272.142:12970): pid=14173 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/211/bus" dev="sda1" ino=17528 res=1 audit: type=1804 audit(1584394272.362:12971): pid=14227 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/212/bus" dev="sda1" ino=17528 res=1 audit: type=1804 audit(1584394272.472:12972): pid=14230 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir711374146/syzkaller.RuCu1j/21/bus" dev="sda1" ino=17564 res=1 netlink: 36 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 36 bytes leftover after parsing attributes in process `syz-executor.1'. ip_tables: iptables: counters copy to user failed while replacing table audit: type=1804 audit(1584394273.362:12973): pid=14270 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/213/bus" dev="sda1" ino=17568 res=1 audit: type=1804 audit(1584394273.462:12974): pid=14277 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir711374146/syzkaller.RuCu1j/22/bus" dev="sda1" ino=17564 res=1 ip_tables: iptables: counters copy to user failed while replacing table audit: type=1804 audit(1584394274.342:12975): pid=14295 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/214/bus" dev="sda1" ino=17090 res=1 audit: type=1400 audit(1584394274.632:12976): avc: denied { sys_admin } for pid=14308 comm="syz-executor.5" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 9pnet: p9_fd_create_unix (14313): problem connecting socket: ./file0: -111 9pnet: p9_fd_create_unix (14316): problem connecting socket: ./file0: -111 usb usb7: usbfs: process 14317 (syz-executor.1) did not claim interface 0 before use audit: type=1804 audit(1584394275.352:12977): pid=14342 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/215/bus" dev="sda1" ino=17571 res=1 x_tables: ip_tables: rpfilter match: used from hooks INPUT, but only valid from PREROUTING audit: type=1804 audit(1584394276.292:12978): pid=14378 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/216/bus" dev="sda1" ino=17571 res=1 ip_tables: iptables: counters copy to user failed while replacing table ip_tables: iptables: counters copy to user failed while replacing table netlink: 20 bytes leftover after parsing attributes in process `syz-executor.5'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 audit: type=1804 audit(1584394277.272:12979): pid=14427 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/217/bus" dev="sda1" ino=17571 res=1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=14424 comm=syz-executor.5 netlink: 20 bytes leftover after parsing attributes in process `syz-executor.5'. SELinux: unknown mount option SELinux: unknown mount option IPVS: ip_vs_svc_hash(): request for already hashed, called from do_ip_vs_set_ctl+0xbab/0xca0 net/netfilter/ipvs/ip_vs_ctl.c:2483 IPVS: ip_vs_svc_hash(): request for already hashed, called from do_ip_vs_set_ctl+0xbab/0xca0 net/netfilter/ipvs/ip_vs_ctl.c:2483 ip_tables: iptables: counters copy to user failed while replacing table audit: type=1804 audit(1584394278.272:12980): pid=14470 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir210218315/syzkaller.wh8jz0/218/bus" dev="sda1" ino=17582 res=1