{"id":"CVE-2024-56647","revision":"beeabe7e9c6746d0910a17db0c8131d8","records":[{"revision":"beeabe7e9c6746d0910a17db0c8131d8","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2024-56647","aliases":[],"title":"net: Fix icmp host relookup triggering ip_rt_bug","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: Fix icmp host relookup triggering ip_rt_bug\n\narp link failure may trigger ip_rt_bug while xfrm enabled, call trace is:\n\nWARNING: CPU: 0 PID: 0 at net/ipv4/route.c:1241 ip_rt_bug+0x14/0x20\nModules linked in:\nCPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc6-00077-g2e1b3cc9d7f7\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996),\nBIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014\nRIP: 0010:ip_rt_bug+0x14/0x20\nCall Trace:\n <IRQ>\n ip_send_skb+0x14/0x40\n __icmp_send+0x42d/0x6a0\n ipv4_link_failure+0xe2/0x1d0\n arp_error_report+0x3c/0x50\n neigh_invalidate+0x8d/0x100\n neigh_timer_handler+0x2e1/0x330\n call_timer_fn+0x21/0x120\n __run_timer_base.part.0+0x1c9/0x270\n run_timer_softirq+0x4c/0x80\n handle_softirqs+0xac/0x280\n irq_exit_rcu+0x62/0x80\n sysvec_apic_timer_interrupt+0x77/0x90\n\nThe script below reproduces this scenario:\nip xfrm policy add src 0.0.0.0/0 dst 0.0.0.0/0 \\\n\tdir out priority 0 ptype main flag localok icmp\nip l a veth1 type veth\nip a a 192.168.141.111/24 dev veth0\nip l s veth0 up\nping 192.168.141.155 -c 1\n\nicmp_route_lookup() create input routes for locally generated packets\nwhile xfrm relookup ICMP traffic.Then it will set input route\n(dst->out = ip_rt_bug) to skb for DESTUNREACH.\n\nFor ICMP err triggered by locally generated packets, dst->dev of output\nroute is loopback. Generally, xfrm relookup verification is not required\non loopback interfaces (net.ipv4.conf.lo.disable_xfrm = 1).\n\nSkip icmp relookup for locally generated packets to fix it.","state":0,"publishedAt":"2024-12-27T15:02:47.969+00:00","modifiedAt":"2026-10-15T00:59:58.769+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv4/icmp.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"d50981aaaefc3b04490fbc8274d37881a2b1b112\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"da54b3039d436227deebbc202cefea63bd318a38\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"9545011e7b2a8fc0cbd6e387a09f12cd41d7d82f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"c44daa7e3c73229f7ac74985acb8c7fb909c4e0a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv4/icmp.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"2.6.25\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"2.6.25\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.175\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.140\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.5\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.13\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/d50981aaaefc3b04490fbc8274d37881a2b1b112","https://git.kernel.org/stable/c/da54b3039d436227deebbc202cefea63bd318a38","https://git.kernel.org/stable/c/9545011e7b2a8fc0cbd6e387a09f12cd41d7d82f","https://git.kernel.org/stable/c/c44daa7e3c73229f7ac74985acb8c7fb909c4e0a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2024-56647","license":"CVE Program Terms of Use","key":"cve-program:CVE-2024-56647","identifiers":["CVE-2024-56647"]},"retained":false,"historicalAffected":[]}],"coverage":[]}