{"id":"CVE-2026-99088","revision":"93f7459c58544161a21dfe53c55932b6","records":[{"revision":"93f7459c58544161a21dfe53c55932b6","observedAt":"2026-10-26T15:35:30.984+00:00","statement":{"source":"cve-program","id":"CVE-2026-99088","aliases":[],"title":"net: openvswitch: validate transport header presence in set_ipv6_addr","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: validate transport header presence in set_ipv6_addr\n\nWhen executing IPv6 address rewrite actions on IPv6 fragments,\nset_ipv6_addr() calls update_ipv6_checksum(). If parse_ipv6hdr()\nprocesses a non-first IPv6 fragment, it sets key->ip.proto to\nNEXTHDR_FRAGMENT and returns early without calling\nskb_set_transport_header().\n\nupdate_ipv6_checksum() unconditionally evaluates skb_transport_offset()\non entry before checking l4_proto. Because skb->transport_header is\nuninitialized, this triggers a warning under CONFIG_DEBUG_NET=y although\nit is completely harmless.\n\nFix this by returning early in update_ipv6_checksum() if l4_proto is\nNEXTHDR_FRAGMENT. This avoids reading the uninitialized transport offset\nfor fragments while preserving the debug warning for any other protocol\nwhere the transport header is unexpectedly missing.\n\nSee the syzbot trace:\n\n!skb_transport_header_was_set(skb)\nWARNING: ./include/linux/skbuff.h:3075 at skb_transport_header include/linux/skbuff.h:3075 [inline], CPU#1: syz-executor463/5635\nWARNING: ./include/linux/skbuff.h:3075 at skb_transport_offset include/linux/skbuff.h:3250 [inline], CPU#1: syz-executor463/5635\nWARNING: ./include/linux/skbuff.h:3075 at update_ipv6_checksum net/openvswitch/actions.c:361 [inline], CPU#1: syz-executor463/5635\nWARNING: ./include/linux/skbuff.h:3075 at set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399, CPU#1: syz-executor463/5635\n[...]\nRIP: 0010:skb_transport_header include/linux/skbuff.h:3075 [inline]\nRIP: 0010:skb_transport_offset include/linux/skbuff.h:3250 [inline]\nRIP: 0010:update_ipv6_checksum net/openvswitch/actions.c:361 [inline]\nRIP: 0010:set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399\n[...]\nCall Trace:\n \n set_ipv6 net/openvswitch/actions.c:531 [inline]\n do_execute_actions+0x557e/0x8600 net/openvswitch/actions.c:1366\n ovs_execute_actions+0xde/0x520 net/openvswitch/actions.c:1592\n ovs_packet_cmd_execute+0xb4f/0xf10 net/openvswitch/datapath.c:705\n genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114\n genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209\n netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572\n genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218\n netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361\n netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916\n sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800","state":0,"publishedAt":"2026-10-26T14:51:58.46+00:00","modifiedAt":"2026-10-26T14:51:58.46+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/openvswitch/actions.c\"\n ],\n \"versions\": [\n {\n \"version\": \"3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b\",\n \"lessThan\": \"b7b80d204abdc258006f9e17c92b363ab13bb599\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b\",\n \"lessThan\": \"6774af7cd17be8f0d0f70de3a749d381b4f2e9da\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b\",\n \"lessThan\": \"2594795fd832f0253826d64ff8976b8ff5fbfe9f\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b\",\n \"lessThan\": \"6b8897ba0733f88f0360ea48a970f373f9142de0\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b\",\n \"lessThan\": \"3c6a4b11330fe424557538a98fca9f0a4c5bf313\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/openvswitch/actions.c\"\n ],\n \"versions\": [\n {\n \"version\": \"3.8\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"3.8\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.160\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.113\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.57\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.11\",\n \"lessThanOrEqual\": \"7.2.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.3\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/b7b80d204abdc258006f9e17c92b363ab13bb599","https://git.kernel.org/stable/c/6774af7cd17be8f0d0f70de3a749d381b4f2e9da","https://git.kernel.org/stable/c/2594795fd832f0253826d64ff8976b8ff5fbfe9f","https://git.kernel.org/stable/c/6b8897ba0733f88f0360ea48a970f373f9142de0","https://git.kernel.org/stable/c/3c6a4b11330fe424557538a98fca9f0a4c5bf313"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99088","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-99088","identifiers":["CVE-2026-99088"]},"retained":false,"historicalAffected":[]}],"coverage":[]}