====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.1848/12462 is trying to acquire lock: ffffffff9701ff38 (nfnl_subsys_ipset){+.+.}-{3:3}, at: ip_set_nfnl_get_byindex+0x63/0x230 net/netfilter/ipset/ip_set_core.c:911 but task is already holding lock: ffff88801aad42b8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid+0x37/0x100 net/netfilter/nf_tables_api.c:10236 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&nft_net->commit_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 nf_tables_dumpreset_obj+0x6e/0x90 net/netfilter/nf_tables_api.c:7511 netlink_dump+0x6a3/0xd00 net/netlink/af_netlink.c:2236 __netlink_dump_start+0x537/0x6f0 net/netlink/af_netlink.c:2338 netlink_dump_start include/linux/netlink.h:269 [inline] nft_netlink_dump_start_rcu+0xdb/0x1a0 net/netfilter/nf_tables_api.c:1089 nf_tables_getobj_reset+0x1cb/0x610 net/netfilter/nf_tables_api.c:7646 nfnetlink_rcv_msg+0x8a0/0x12b0 net/netfilter/nfnetlink.c:290 netlink_rcv_skb+0x1fb/0x450 net/netlink/af_netlink.c:2511 nfnetlink_rcv+0x2b0/0x2480 net/netfilter/nfnetlink.c:659 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5be/0x970 net/socket.c:2518 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2572 __sys_sendmsg net/socket.c:2601 [inline] __do_sys_sendmsg net/socket.c:2610 [inline] __se_sys_sendmsg+0x1bb/0x2a0 net/socket.c:2608 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (nlk_cb_mutex-NETFILTER){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305 netlink_dump_start include/linux/netlink.h:269 [inline] ip_set_dump+0x152/0x1e0 net/netfilter/ipset/ip_set_core.c:1719 nfnetlink_rcv_msg+0xbec/0x12b0 net/netfilter/nfnetlink.c:302 netlink_rcv_skb+0x1fb/0x450 net/netlink/af_netlink.c:2511 nfnetlink_rcv+0x2b0/0x2480 net/netfilter/nfnetlink.c:659 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5be/0x970 net/socket.c:2518 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2572 __sys_sendmsg net/socket.c:2601 [inline] __do_sys_sendmsg net/socket.c:2610 [inline] __se_sys_sendmsg+0x1bb/0x2a0 net/socket.c:2608 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (nfnl_subsys_ipset){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 ip_set_nfnl_get_byindex+0x63/0x230 net/netfilter/ipset/ip_set_core.c:911 set_match_v1_checkentry+0x6d/0x220 net/netfilter/xt_set.c:139 xt_check_match+0x425/0xaf0 net/netfilter/x_tables.c:523 __nft_match_init+0x663/0x890 net/netfilter/nft_compat.c:522 nf_tables_newexpr net/netfilter/nf_tables_api.c:3065 [inline] nf_tables_newrule+0x1731/0x2810 net/netfilter/nf_tables_api.c:3792 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:519 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:639 [inline] nfnetlink_rcv+0x1124/0x2480 net/netfilter/nfnetlink.c:657 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5be/0x970 net/socket.c:2518 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2572 __sys_sendmsg net/socket.c:2601 [inline] __do_sys_sendmsg net/socket.c:2610 [inline] __se_sys_sendmsg+0x1bb/0x2a0 net/socket.c:2608 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: nfnl_subsys_ipset --> nlk_cb_mutex-NETFILTER --> &nft_net->commit_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&nft_net->commit_mutex); lock(nlk_cb_mutex-NETFILTER); lock(&nft_net->commit_mutex); lock(nfnl_subsys_ipset); *** DEADLOCK *** 1 lock held by syz.5.1848/12462: #0: ffff88801aad42b8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid+0x37/0x100 net/netfilter/nf_tables_api.c:10236 stack backtrace: CPU: 1 PID: 12462 Comm: syz.5.1848 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 ip_set_nfnl_get_byindex+0x63/0x230 net/netfilter/ipset/ip_set_core.c:911 set_match_v1_checkentry+0x6d/0x220 net/netfilter/xt_set.c:139 xt_check_match+0x425/0xaf0 net/netfilter/x_tables.c:523 __nft_match_init+0x663/0x890 net/netfilter/nft_compat.c:522 nf_tables_newexpr net/netfilter/nf_tables_api.c:3065 [inline] nf_tables_newrule+0x1731/0x2810 net/netfilter/nf_tables_api.c:3792 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:519 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:639 [inline] nfnetlink_rcv+0x1124/0x2480 net/netfilter/nfnetlink.c:657 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5be/0x970 net/socket.c:2518 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2572 __sys_sendmsg net/socket.c:2601 [inline] __do_sys_sendmsg net/socket.c:2610 [inline] __se_sys_sendmsg+0x1bb/0x2a0 net/socket.c:2608 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f79d5d9c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f79d6c1b028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f79d6015fa0 RCX: 00007f79d5d9c799 RDX: 0000000024044010 RSI: 0000200000000100 RDI: 0000000000000003 RBP: 00007f79d5e32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f79d6016038 R14: 00007f79d6015fa0 R15: 00007fff4e566528 Cannot find set identified by id 0 to match