CVE-2026-64554

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment()<br /> <br /> br_ip6_fragment() gets prevhdr, a pointer into the skb head, from<br /> ip6_find_1stfragopt(), then calls skb_checksum_help(). For a cloned skb<br /> skb_checksum_help() reallocates the head via pskb_expand_head(), leaving<br /> prevhdr dangling. It is later dereferenced in ip6_frag_next(), causing a<br /> use-after-free write.<br /> <br /> Save prevhdr&amp;#39;s offset before skb_checksum_help() and recompute it after,<br /> like commit ef0efcd3bd3f ("ipv6: Fix dangling pointer when ipv6<br /> fragment").<br /> <br /> BUG: KASAN: slab-use-after-free in ip6_frag_next (net/ipv6/ip6_output.c:857)<br /> Write of size 1 at addr ffff888013ff5016 by task exploit/141<br /> Call Trace:<br /> ...<br /> kasan_report (mm/kasan/report.c:595)<br /> ip6_frag_next (net/ipv6/ip6_output.c:857)<br /> br_ip6_fragment (net/ipv6/netfilter.c:212)<br /> nf_ct_bridge_post (net/bridge/netfilter/nf_conntrack_bridge.c:407)<br /> nf_hook_slow (net/netfilter/core.c:619)<br /> br_forward_finish (net/bridge/br_forward.c:66)<br /> __br_forward (net/bridge/br_forward.c:115)<br /> maybe_deliver (net/bridge/br_forward.c:191)<br /> br_flood (net/bridge/br_forward.c:245)<br /> br_handle_frame_finish (net/bridge/br_input.c:229)<br /> br_handle_frame (net/bridge/br_input.c:442)<br /> ...<br /> packet_sendmsg (net/packet/af_packet.c:3114)<br /> ...<br /> do_syscall_64 (arch/x86/entry/syscall_64.c:94)<br /> entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)<br /> Kernel panic - not syncing: Fatal exception in interrupt