audit: type=1401 audit(1574728322.152:503): op=setxattr invalid_context=73797374656D5F753A6F626A6563745F723A7661725F73706F6F6C5F743A73303A000039D587DB272011B2708A5FCCC3864E1865A3134B2431970C3FBA39C805AD1CF34A5C27FCF60F1A audit: type=1401 audit(1574728322.162:504): op=setxattr invalid_context=73797374656D5F753A6F626A6563745F723A7661725F73706F6F6C5F743A73303A000039D587DB272011B2708A5FCCC3864E1865A3134B2431970C3FBA39C805AD1CF34A5C27FCF60F1A ====================================================== [ INFO: possible circular locking dependency detected ] 4.9.141+ #1 Not tainted ------------------------------------------------------- syz-executor.0/21400 is trying to acquire lock: (&sig->cred_guard_mutex){+.+.+.}, at: [] do_io_accounting+0x1fb/0x7e0 fs/proc/base.c:2690 but task is already holding lock: (&p->lock){+.+.+.}, at: [] seq_read+0xdd/0x12d0 fs/seq_file.c:178 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756 __mutex_lock_common kernel/locking/mutex.c:521 [inline] mutex_lock_nested+0xc0/0x900 kernel/locking/mutex.c:621 seq_read+0xdd/0x12d0 fs/seq_file.c:178 proc_reg_read+0xfd/0x180 fs/proc/inode.c:203 do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718 do_loop_readv_writev fs/read_write.c:707 [inline] do_readv_writev+0x56e/0x7b0 fs/read_write.c:873 vfs_readv+0x84/0xc0 fs/read_write.c:897 kernel_readv fs/splice.c:363 [inline] default_file_splice_read+0x451/0x7f0 fs/splice.c:435 do_splice_to+0x10c/0x170 fs/splice.c:899 do_splice fs/splice.c:1192 [inline] SYSC_splice fs/splice.c:1416 [inline] SyS_splice+0x10d2/0x14d0 fs/splice.c:1399 do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285 entry_SYSCALL_64_after_swapgs+0x5d/0xdb lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756 __mutex_lock_common kernel/locking/mutex.c:521 [inline] mutex_lock_nested+0xc0/0x900 kernel/locking/mutex.c:621 __pipe_lock fs/pipe.c:87 [inline] fifo_open+0x15c/0x9e0 fs/pipe.c:921 do_dentry_open+0x3ef/0xc90 fs/open.c:766 vfs_open+0x11c/0x210 fs/open.c:879 do_last fs/namei.c:3410 [inline] path_openat+0x542/0x2790 fs/namei.c:3534 do_filp_open+0x197/0x270 fs/namei.c:3568 do_open_execat+0x10f/0x640 fs/exec.c:844 do_execveat_common.isra.14+0x687/0x1ed0 fs/exec.c:1723 do_execve fs/exec.c:1829 [inline] SYSC_execve fs/exec.c:1910 [inline] SyS_execve+0x42/0x50 fs/exec.c:1905 do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285 entry_SYSCALL_64_after_swapgs+0x5d/0xdb check_prev_add kernel/locking/lockdep.c:1828 [inline] check_prevs_add kernel/locking/lockdep.c:1938 [inline] validate_chain kernel/locking/lockdep.c:2265 [inline] __lock_acquire+0x3189/0x4a10 kernel/locking/lockdep.c:3345 lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756 __mutex_lock_common kernel/locking/mutex.c:521 [inline] mutex_lock_killable_nested+0xcc/0x9f0 kernel/locking/mutex.c:641 do_io_accounting+0x1fb/0x7e0 fs/proc/base.c:2690 proc_tgid_io_accounting+0x22/0x30 fs/proc/base.c:2739 proc_single_show+0xfd/0x170 fs/proc/base.c:785 seq_read+0x4b6/0x12d0 fs/seq_file.c:240 do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718 do_loop_readv_writev fs/read_write.c:707 [inline] do_readv_writev+0x56e/0x7b0 fs/read_write.c:873 vfs_readv+0x84/0xc0 fs/read_write.c:897 do_preadv+0x197/0x240 fs/read_write.c:974 SYSC_preadv fs/read_write.c:1024 [inline] SyS_preadv+0x30/0x40 fs/read_write.c:1019 do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285 entry_SYSCALL_64_after_swapgs+0x5d/0xdb other info that might help us debug this: Chain exists of: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->lock); lock(&pipe->mutex/1); lock(&p->lock); lock(&sig->cred_guard_mutex); *** DEADLOCK *** 1 lock held by syz-executor.0/21400: #0: (&p->lock){+.+.+.}, at: [] seq_read+0xdd/0x12d0 fs/seq_file.c:178 stack backtrace: CPU: 0 PID: 21400 Comm: syz-executor.0 Not tainted 4.9.141+ #1 ffff8800ba787528 ffffffff81b42e79 ffffffff83caa290 ffffffff83ca4fe0 ffffffff83ca2fd0 ffff88012d65d010 ffff88012d65c740 ffff8800ba787570 ffffffff813fee40 0000000000000001 000000002d65cff0 0000000000000001 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_circular_bug.cold.36+0x2f7/0x432 kernel/locking/lockdep.c:1202 [] check_prev_add kernel/locking/lockdep.c:1828 [inline] [] check_prevs_add kernel/locking/lockdep.c:1938 [inline] [] validate_chain kernel/locking/lockdep.c:2265 [inline] [] __lock_acquire+0x3189/0x4a10 kernel/locking/lockdep.c:3345 [] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756 [] __mutex_lock_common kernel/locking/mutex.c:521 [inline] [] mutex_lock_killable_nested+0xcc/0x9f0 kernel/locking/mutex.c:641 [] do_io_accounting+0x1fb/0x7e0 fs/proc/base.c:2690 [] proc_tgid_io_accounting+0x22/0x30 fs/proc/base.c:2739 [] proc_single_show+0xfd/0x170 fs/proc/base.c:785 [] seq_read+0x4b6/0x12d0 fs/seq_file.c:240 [] do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718 [] do_loop_readv_writev fs/read_write.c:707 [inline] [] do_readv_writev+0x56e/0x7b0 fs/read_write.c:873 [] vfs_readv+0x84/0xc0 fs/read_write.c:897 [] do_preadv+0x197/0x240 fs/read_write.c:974 [] SYSC_preadv fs/read_write.c:1024 [inline] [] SyS_preadv+0x30/0x40 fs/read_write.c:1019 [] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready netlink: 27 bytes leftover after parsing attributes in process `syz-executor.2'. qtaguid: iface_stat: create6(lo): no inet dev netlink: 27 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 27 bytes leftover after parsing attributes in process `syz-executor.2'. ip6_tunnel: ip6tnl1 xmit: Local address not yet configured! netlink: 27 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 27 bytes leftover after parsing attributes in process `syz-executor.2'. IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready qtaguid: iface_stat: create6(lo): no inet dev ip6_tunnel: ip6tnl1 xmit: Local address not yet configured! IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready netlink: 27 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 27 bytes leftover after parsing attributes in process `syz-executor.2'. qtaguid: iface_stat: create6(lo): no inet dev IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): ip_vti0: link becomes ready ip6_tunnel: ip6tnl1 xmit: Local address not yet configured! IPv6: ADDRCONF(NETDEV_CHANGE): vti27: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti28: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti29: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti30: link becomes ready device sit74 left promiscuous mode IPv6: ADDRCONF(NETDEV_CHANGE): sit74: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): sit74: link becomes ready device sit75 left promiscuous mode IPv6: ADDRCONF(NETDEV_CHANGE): sit75: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): sit75: link becomes ready device sit76 left promiscuous mode IPv6: ADDRCONF(NETDEV_CHANGE): sit76: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): sit76: link becomes ready ip6_tunnel: ip6tnl1 xmit: Local address not yet configured! IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready qtaguid: iface_stat: create6(lo): no inet dev ip6_tunnel: ip6tnl1 xmit: Local address not yet configured! IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): ip_vti0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti27: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti28: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti29: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti30: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): sit74: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): sit75: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): sit76: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready qtaguid: iface_stat: create6(lo): no inet dev IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready ip6_tunnel: ip6tnl1 xmit: Local address not yet configured! IPv6: ADDRCONF(NETDEV_CHANGE): ip_vti0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti27: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti28: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti29: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vti30: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): sit74: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): sit75: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): sit76: link becomes ready SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21613 comm=syz-executor.5 ip6_tunnel: ip6tnl1 xmit: Local address not yet configured! SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21649 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21664 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21668 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21669 comm=syz-executor.2 selinux_nlmsg_perm: 1 callbacks suppressed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21704 comm=syz-executor.5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21705 comm=syz-executor.0 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21712 comm=syz-executor.3 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21731 comm=syz-executor.2 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21734 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21735 comm=syz-executor.4 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21750 comm=syz-executor.4 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21756 comm=syz-executor.3 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21762 comm=syz-executor.0 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12152 sclass=netlink_route_socket pig=21769 comm=syz-executor.5