In the Linux kernel, the following vulnerability has been resolved:
net: Fix icmp host relookup triggering iprtbug
arp link failure may trigger iprtbug while xfrm enabled, call trace is:
WARNING: CPU: 0 PID: 0 at net/ipv4/route.c:1241 iprtbug+0x14/0x20 Modules linked in: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc6-00077-g2e1b3cc9d7f7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:iprtbug+0x14/0x20 Call Trace: <IRQ> ipsendskb+0x14/0x40 _icmpsend+0x42d/0x6a0 ipv4linkfailure+0xe2/0x1d0 arperrorreport+0x3c/0x50 neighinvalidate+0x8d/0x100 neightimerhandler+0x2e1/0x330 calltimerfn+0x21/0x120 _runtimerbase.part.0+0x1c9/0x270 runtimersoftirq+0x4c/0x80 handlesoftirqs+0xac/0x280 irqexitrcu+0x62/0x80 sysvecapictimerinterrupt+0x77/0x90
The script below reproduces this scenario: ip xfrm policy add src 0.0.0.0/0 dst 0.0.0.0/0 \ dir out priority 0 ptype main flag localok icmp ip l a veth1 type veth ip a a 192.168.141.111/24 dev veth0 ip l s veth0 up ping 192.168.141.155 -c 1
icmproutelookup() create input routes for locally generated packets while xfrm relookup ICMP traffic.Then it will set input route (dst->out = iprtbug) to skb for DESTUNREACH.
For ICMP err triggered by locally generated packets, dst->dev of output route is loopback. Generally, xfrm relookup verification is not required on loopback interfaces (net.ipv4.conf.lo.disable_xfrm = 1).
Skip icmp relookup for locally generated packets to fix it.
[ { "signature_type": "Function", "deprecated": false, "source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@9545011e7b2a8fc0cbd6e387a09f12cd41d7d82f", "signature_version": "v1", "target": { "function": "icmp_route_lookup", "file": "net/ipv4/icmp.c" }, "digest": { "function_hash": "235769223198235940083402335238748735395", "length": 2295.0 }, "id": "CVE-2024-56647-4689d796" }, { "signature_type": "Line", "deprecated": false, "source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@9545011e7b2a8fc0cbd6e387a09f12cd41d7d82f", "signature_version": "v1", "target": { "file": "net/ipv4/icmp.c" }, "digest": { "threshold": 0.9, "line_hashes": [ "228387910014710849975102377426559337579", "165328704902215836853985331524167859604", "298348283953532631911432029252128745040", "191098374420387270497501150757039863109" ] }, "id": "CVE-2024-56647-5b6457db" }, { "signature_type": "Function", "deprecated": false, "source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@c44daa7e3c73229f7ac74985acb8c7fb909c4e0a", "signature_version": "v1", "target": { "function": "icmp_route_lookup", "file": "net/ipv4/icmp.c" }, "digest": { "function_hash": "261498141547736033337333892407494073304", "length": 2306.0 }, "id": "CVE-2024-56647-8be3b0f2" }, { "signature_type": "Line", "deprecated": false, "source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@c44daa7e3c73229f7ac74985acb8c7fb909c4e0a", "signature_version": "v1", "target": { "file": "net/ipv4/icmp.c" }, "digest": { "threshold": 0.9, "line_hashes": [ "228387910014710849975102377426559337579", "165328704902215836853985331524167859604", "298348283953532631911432029252128745040", "191098374420387270497501150757039863109" ] }, "id": "CVE-2024-56647-e58f8fda" } ]