{"cve":"CVE-2024-56647","nvd":{"published":"2024-12-27T15:15:24.467","modified":"2026-10-15T02:17:08.380","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/9545011e7b2a8fc0cbd6e387a09f12cd41d7d82f","https://git.kernel.org/stable/c/c44daa7e3c73229f7ac74985acb8c7fb909c4e0a","https://git.kernel.org/stable/c/d50981aaaefc3b04490fbc8274d37881a2b1b112","https://git.kernel.org/stable/c/da54b3039d436227deebbc202cefea63bd318a38","https://cert-portal.siemens.com/productcert/html/ssa-784472.html"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:57:56.913276502+00:00"},"epss":{"cve":"CVE-2024-56647","score":0.00223,"percentile":0.12809,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}