CVE-2026-64114

CVE CVE-2026-64114EUVD EUVD-2026-45799Veröffentlicht 2026-07-19T15:40:14.000ZZuletzt geändert 2026-08-05T12:39:23.000ZCVSS 7.8

Was das Advisory beschreibt

In the Linux kernel, the following vulnerability has been resolved: ipv4: raw: reject IP_HDRINCL packets with ihl < 5 raw_send_hdrinc() validates that the caller-supplied IPv4 header fits within the message length: iphlen = iph->ihl * 4; err = -EINVAL; if (iphlen > length) goto error_free; if (iphlen >= sizeof(*iph)) { /* fix up saddr, tot_len, id, csum, transport_header */ } It does not, however, reject ihl < 5. For such a packet the "if (iphlen >= sizeof(*iph))" branch is skipped, leaving the crafted iphdr untouched, but the packet is still handed to __ip_local_out() and onward. Downstream consumers that read iph->ihl assume a sane value: net/ipv4/ah4.c:ah_output() in particular subtracts sizeof(struct iphdr) from top_iph->ihl * 4 and passes the (signed-int-negative, then cast to size_t) result to memcpy(), producing an OOB access of length close to SIZE_MAX and a host kernel panic. An IPv4 header with ihl < 5 is malformed by definition (RFC 791: "Internet Header Length is the length of the internet header in 32 bit words ... Note that the minimum value for a correct header is 5."). The kernel should not be willing to inject such a packet into its own output path. Reject "iphlen < sizeof(*iph)" alongside the existing "iphlen > length" check. This matches the principle that locally constructed packets that re-enter the IP stack must pass the same basic sanity tests that a foreign packet would be subjected to. Once this lands, the "if (iphlen >= sizeof(*iph))" wrapper around the fixup branch becomes redundant; left in place to keep the patch minimal and backport-friendly. A follow-up can unwrap it. Note that commit 86f4c90a1c5c ("ipv4, ipv6: ensure raw socket message is big enough to hold an IP header") ensures the message buffer is large enough to hold an iphdr, but does not constrain the self-reported iph->ihl. Reachability: the malformed packet source is any caller with CAP_NET_RAW, including an unprivileged process in a user+net namespace on a kernel with CONFIG_USER_NS=y. The reproduced AH crash also requires a matching xfrm AH policy on the outgoing route; a container granted CAP_NET_ADMIN can install that state and policy in its netns. Loopback bypasses xfrm_output, so the trigger uses a real netdev. Reproduced on UML + KASAN: kernel-mode fault at addr 0x0 with memcpy_orig at the crash site. Same shape reproduces inside a rootless Docker container with --cap-add NET_ADMIN on a stock distro kernel.

Quelle: EUVD (ENISA), im Wortlaut der Meldung.

Produkte, die das Advisory nennt

Diese Angaben stammen aus der Meldung selbst, nicht aus einer Prüfung durch uns.

• Linux — Linux patch: 7.0.11; patch: 5.15.209; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7725cd3b471740fd23d25ed1da722c671fb2a5d3; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5a564f737ec54d63e8ee221d3ff396d07586d464; patch: 6.12.92; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3c5411fa4944ed99af3d9d1de750ea8169b6dac9; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bbe0be67de296176e7243c76e3d9f02f6ae9ff0b; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <915fab69823a14c170dbaa3b41978768e0fe62fc; patch: 5.10.258; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bc20dbd48c26e743f7e0845020c11ed2ce8b15ee; patch: 6.1.175; 2.6.12; patch: 6.18.34; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1065b9efa4126df559b03a849c139ecfae92cd25; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <145e9afa5b905229b4788bb72c3255f5a5f77508; patch: 6.6.142; patch: 7.1; patch: 0

Die genannten Versionen sind die Angabe der Meldung. Patchlage vergleicht keine Versionsnummern und leitet aus ihnen keine Aussage ab — welche Version installiert ist, muss ein Mensch nachsehen.

Im Produktkatalog geführt

Für diese Produkte kann ein Bestand in Patchlage erfasst werden. Ein Advisory dazu erscheint am Morgen danach im Lagebericht.

• Linux — Linux

Patchlage meldet Treffer und Verdachtsfälle. Zu allem anderen sagt dieses System nichts — weder diese Seite noch der Lagebericht behauptet je, dass ein Bestand sicher ist.