ip_tables: iptables: counters copy to user failed while replacing table ptrace attach of "/root/syz-executor.1"[26732] was attempted by "/root/syz-executor.1"[26736] ====================================================== WARNING: possible circular locking dependency detected 4.14.172-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/26726 is trying to acquire lock: (&table[i].mutex){+.+.}, at: [] ip_set_nfnl_put+0x11b/0x310 net/netfilter/ipset/ip_set_core.c:730 but task is already holding lock: (&xt[i].mutex){+.+.}, at: [] xt_find_table_lock+0x35/0x3d0 net/netfilter/x_tables.c:1092 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&xt[i].mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 xt_find_revision+0x89/0x200 net/netfilter/x_tables.c:373 nfnl_compat_get+0x1f7/0x8a0 net/netfilter/nft_compat.c:678 nfnetlink_rcv_msg+0xa08/0xc00 net/netfilter/nfnetlink.c:214 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2432 nfnetlink_rcv+0x1ab/0x1650 net/netfilter/nfnetlink.c:515 netlink_unicast_kernel net/netlink/af_netlink.c:1286 [inline] netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1312 netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1877 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc5/0x100 net/socket.c:656 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (&table[i].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 ip_set_nfnl_put+0x11b/0x310 net/netfilter/ipset/ip_set_core.c:730 set_target_v1_destroy+0xd7/0x150 net/netfilter/xt_set.c:392 cleanup_entry+0x169/0x220 net/ipv4/netfilter/ip_tables.c:666 __do_replace+0x38d/0x570 net/ipv4/netfilter/ip_tables.c:1086 do_replace net/ipv4/netfilter/ip_tables.c:1142 [inline] do_ipt_set_ctl+0x255/0x39d net/ipv4/netfilter/ip_tables.c:1674 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x5f/0xb0 net/netfilter/nf_sockopt.c:115 ip_setsockopt net/ipv4/ip_sockglue.c:1255 [inline] ip_setsockopt+0x94/0xb0 net/ipv4/ip_sockglue.c:1240 raw_setsockopt+0xac/0xd0 net/ipv4/raw.c:855 SYSC_setsockopt net/socket.c:1865 [inline] SyS_setsockopt+0x110/0x1e0 net/socket.c:1844 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: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&xt[i].mutex); lock(&table[i].mutex); lock(&xt[i].mutex); lock(&table[i].mutex); *** DEADLOCK *** 1 lock held by syz-executor.4/26726: #0: (&xt[i].mutex){+.+.}, at: [] xt_find_table_lock+0x35/0x3d0 net/netfilter/x_tables.c:1092 stack backtrace: CPU: 0 PID: 26726 Comm: syz-executor.4 Not tainted 4.14.172-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 ip_set_nfnl_put+0x11b/0x310 net/netfilter/ipset/ip_set_core.c:730 set_target_v1_destroy+0xd7/0x150 net/netfilter/xt_set.c:392 cleanup_entry+0x169/0x220 net/ipv4/netfilter/ip_tables.c:666 __do_replace+0x38d/0x570 net/ipv4/netfilter/ip_tables.c:1086 do_replace net/ipv4/netfilter/ip_tables.c:1142 [inline] do_ipt_set_ctl+0x255/0x39d net/ipv4/netfilter/ip_tables.c:1674 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x5f/0xb0 net/netfilter/nf_sockopt.c:115 ip_setsockopt net/ipv4/ip_sockglue.c:1255 [inline] ip_setsockopt+0x94/0xb0 net/ipv4/ip_sockglue.c:1240 raw_setsockopt+0xac/0xd0 net/ipv4/raw.c:855 SYSC_setsockopt net/socket.c:1865 [inline] SyS_setsockopt+0x110/0x1e0 net/socket.c:1844 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c479 RSP: 002b:00007f6adb4d2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f6adb4d36d4 RCX: 000000000045c479 RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000076bf20 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000020000240 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000a34 R14: 00000000004cc9d4 R15: 000000000076bf2c ip_tables: iptables: counters copy to user failed while replacing table ip_tables: iptables: counters copy to user failed while replacing table ip_tables: iptables: counters copy to user failed while replacing table netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. ip_tables: iptables: counters copy to user failed while replacing table ip_tables: iptables: counters copy to user failed while replacing table ip_tables: iptables: counters copy to user failed while replacing table ip_tables: iptables: counters copy to user failed while replacing table ip_tables: iptables: counters copy to user failed while replacing table ip_tables: iptables: counters copy to user failed while replacing table