{"id":"CVE-2024-56647","title":"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:…","summary":"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:…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 2.6.25, < 6.12.5","linux_kernel = 6.13"],"patched":["linux_kernel 6.12.5"],"published":"2024-12-27","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:17:08.380","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2024-56647","references":[{"url":"https://git.kernel.org/stable/c/9545011e7b2a8fc0cbd6e387a09f12cd41d7d82f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c44daa7e3c73229f7ac74985acb8c7fb909c4e0a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d50981aaaefc3b04490fbc8274d37881a2b1b112","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/da54b3039d436227deebbc202cefea63bd318a38","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00223,"epssPercentile":0.12848,"ingestedAt":"2026-10-15T03:30:12.774Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2025-10-01T20:00:32.629636Z"},"slug":"CVE-2024-56647","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `linux_kernel >= 2.6.25, < 6.12.5`\n- `linux_kernel = 6.13`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.12.5`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}