CVE-2026-68302

CVE CVE-2026-68302EUVD EUVD-2026-55403Veröffentlicht 2026-08-10T12:02:36.000Z

Was das Advisory beschreibt

In the Linux kernel, the following vulnerability has been resolved: amt: re-read skb header pointers after every pull Several AMT receive and transmit paths cache a pointer into the skb head (ip_hdr(), ipv6_hdr(), eth_hdr() or the AMT message header) and then call a helper that can reallocate that head before the cached pointer is used again. pskb_may_pull(), ip_mc_may_pull(), ipv6_mc_may_pull(), iptunnel_pull_header(), ip_mc_check_igmp() and ipv6_mc_check_mld() can all free the old head and move the data, so a pointer taken before the call dangles afterwards and the later access is a use-after-free of the freed head. The affected sites are: amt_rcv() caches ip_hdr() before amt_parse_type() pulls, then reads iph->saddr. amt_dev_xmit() caches ip_hdr()/ipv6_hdr() before ip_mc_check_igmp()/ ipv6_mc_check_mld() and pskb_may_pull(), then reads the group address. amt_multicast_data_handler() caches eth_hdr() before pskb_may_pull(), then writes the L2 header. amt_membership_query_handler() caches the AMT header, the outer and inner eth_hdr() and ip_hdr() before iptunnel_pull_header() and several pulls, then reads and writes them. amt_igmpv3_report_handler() and amt_mldv2_report_handler() cache ip_hdr()/ipv6_hdr() and the current group record and read the record count from the report header inside the record loop, across the *_mc_may_pull() calls. amt_update_handler() caches ip_hdr() and the AMT membership-update header before pskb_may_pull(), iptunnel_pull_header(), ip_mc_check_igmp() and the report handler, then reads iph->daddr and amtmu->nonce / amtmu->response_mac. Fix each site by either snapshotting the scalar that is used after the pull before the first pull runs, or re-deriving the header pointer from the skb after the last pull that can move the head. Values that are stable across the pull (source and group address, the response MAC and nonce, the record count, the outer source MAC) are snapshotted; pointers that are written through or read repeatedly are re-derived.

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 5.16; patch: 6.6.148; patch: 6.12.101; cbc21dc1cfe949e37b2a54c71511579f1899e8d4 <9005b221cb1f9c3c1a2ef656fb0e8fa80c0a187e; cbc21dc1cfe949e37b2a54c71511579f1899e8d4 <3656a79f94c471827a08f2cacce5f94ad5e52c24; patch: 7.2-rc5; cbc21dc1cfe949e37b2a54c71511579f1899e8d4 <7746d588d42a4ac0117b68ed8e9b22a9da53dfb7; patch: 7.1.6; patch: 6.18.42; patch: 0; cbc21dc1cfe949e37b2a54c71511579f1899e8d4 <ca0e8b661957f777591efe874cd9d9a63619cd99; cbc21dc1cfe949e37b2a54c71511579f1899e8d4 <7f48e3ddad8e97545b25788b8203b3a539df1621

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.