Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 1 UID: 0 PID: 6399 Comm: syz.1.285 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:flow_block_cb_is_busy net/core/flow_offload.c:328 [inline] RIP: 0010:flow_block_cb_setup_simple+0x1be/0x740 net/core/flow_offload.c:353 Code: f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 69 fe a0 f8 4d 8b 2e 4d 39 f5 0f 84 b6 00 00 00 49 8d 6d 20 48 89 e8 48 c1 e8 03 <80> 3c 18 00 74 08 48 89 ef e8 44 fe a0 f8 4c 39 65 00 74 07 e8 29 RSP: 0018:ffffc900037ee6f0 EFLAGS: 00010202 RAX: 0000000000000004 RBX: dffffc0000000000 RCX: ffff8880253b5ac0 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888058476000 RBP: 0000000000000020 R08: ffff8880253b5ac0 R09: 0000000000000002 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff87244930 R13: 0000000000000000 R14: ffffffff8f1c78c0 R15: ffff88807aaf0d80 FS: 00005555680f7500(0000) GS:ffff8881258a7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000380 CR3: 0000000077c46000 CR4: 00000000003526f0 Call Trace: nft_block_offload_cmd net/netfilter/nf_tables_offload.c:397 [inline] nft_chain_offload_cmd+0x293/0x660 net/netfilter/nf_tables_offload.c:451 nft_flow_block_chain net/netfilter/nf_tables_offload.c:471 [inline] nft_flow_offload_chain net/netfilter/nf_tables_offload.c:513 [inline] nft_flow_rule_offload_commit+0x814/0x1b60 net/netfilter/nf_tables_offload.c:584 nf_tables_commit+0x69b/0xa1b0 net/netfilter/nf_tables_api.c:10925 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:574 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:647 [inline] nfnetlink_rcv+0x1a4e/0x2520 net/netfilter/nfnetlink.c:665 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2617 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2671 __sys_sendmsg net/socket.c:2703 [inline] __do_sys_sendmsg net/socket.c:2708 [inline] __se_sys_sendmsg net/socket.c:2706 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2706 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe42898eba9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff936441a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe428bd5fa0 RCX: 00007fe42898eba9 RDX: 0000000000000000 RSI: 000020000000c2c0 RDI: 0000000000000003 RBP: 00007fe428a11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe428bd5fa0 R14: 00007fe428bd5fa0 R15: 0000000000000003 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:flow_block_cb_is_busy net/core/flow_offload.c:328 [inline] RIP: 0010:flow_block_cb_setup_simple+0x1be/0x740 net/core/flow_offload.c:353 ---------------- Code disassembly (best guess): 0: f0 48 c1 e8 03 lock shr $0x3,%rax 5: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) 9: 74 08 je 0x13 b: 4c 89 f7 mov %r14,%rdi e: e8 69 fe a0 f8 call 0xf8a0fe7c 13: 4d 8b 2e mov (%r14),%r13 16: 4d 39 f5 cmp %r14,%r13 19: 0f 84 b6 00 00 00 je 0xd5 1f: 49 8d 6d 20 lea 0x20(%r13),%rbp 23: 48 89 e8 mov %rbp,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 48 89 ef mov %rbp,%rdi 33: e8 44 fe a0 f8 call 0xf8a0fe7c 38: 4c 39 65 00 cmp %r12,0x0(%rbp) 3c: 74 07 je 0x45 3e: e8 .byte 0xe8 3f: 29 .byte 0x29