FKIE_CVE-2026-99088

Vulnerability from fkie_nvd - Published: 2026-10-26 15:16 - Updated: 2026-10-30 13:21
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: validate transport header presence in set_ipv6_addr When executing IPv6 address rewrite actions on IPv6 fragments, set_ipv6_addr() calls update_ipv6_checksum(). If parse_ipv6hdr() processes a non-first IPv6 fragment, it sets key->ip.proto to NEXTHDR_FRAGMENT and returns early without calling skb_set_transport_header(). update_ipv6_checksum() unconditionally evaluates skb_transport_offset() on entry before checking l4_proto. Because skb->transport_header is uninitialized, this triggers a warning under CONFIG_DEBUG_NET=y although it is completely harmless. Fix this by returning early in update_ipv6_checksum() if l4_proto is NEXTHDR_FRAGMENT. This avoids reading the uninitialized transport offset for fragments while preserving the debug warning for any other protocol where the transport header is unexpectedly missing. See the syzbot trace: !skb_transport_header_was_set(skb) WARNING: ./include/linux/skbuff.h:3075 at skb_transport_header include/linux/skbuff.h:3075 [inline], CPU#1: syz-executor463/5635 WARNING: ./include/linux/skbuff.h:3075 at skb_transport_offset include/linux/skbuff.h:3250 [inline], CPU#1: syz-executor463/5635 WARNING: ./include/linux/skbuff.h:3075 at update_ipv6_checksum net/openvswitch/actions.c:361 [inline], CPU#1: syz-executor463/5635 WARNING: ./include/linux/skbuff.h:3075 at set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399, CPU#1: syz-executor463/5635 [...] RIP: 0010:skb_transport_header include/linux/skbuff.h:3075 [inline] RIP: 0010:skb_transport_offset include/linux/skbuff.h:3250 [inline] RIP: 0010:update_ipv6_checksum net/openvswitch/actions.c:361 [inline] RIP: 0010:set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399 [...] Call Trace: <TASK> set_ipv6 net/openvswitch/actions.c:531 [inline] do_execute_actions+0x557e/0x8600 net/openvswitch/actions.c:1366 ovs_execute_actions+0xde/0x520 net/openvswitch/actions.c:1592 ovs_packet_cmd_execute+0xb4f/0xf10 net/openvswitch/datapath.c:705 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1efa6842e94aa70237446b31fbe2bc16586809c3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2594795fd832f0253826d64ff8976b8ff5fbfe9f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3c6a4b11330fe424557538a98fca9f0a4c5bf313
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/54cb98ed23866205926298621e04169f50665b59
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6774af7cd17be8f0d0f70de3a749d381b4f2e9da
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6b8897ba0733f88f0360ea48a970f373f9142de0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ad4258db21e801a7aae614afca89a2e39283080d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b7b80d204abdc258006f9e17c92b363ab13bb599
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/openvswitch/actions.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1efa6842e94aa70237446b31fbe2bc16586809c3",
              "status": "affected",
              "version": "3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b",
              "versionType": "git"
            },
            {
              "lessThan": "ad4258db21e801a7aae614afca89a2e39283080d",
              "status": "affected",
              "version": "3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b",
              "versionType": "git"
            },
            {
              "lessThan": "54cb98ed23866205926298621e04169f50665b59",
              "status": "affected",
              "version": "3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b",
              "versionType": "git"
            },
            {
              "lessThan": "b7b80d204abdc258006f9e17c92b363ab13bb599",
              "status": "affected",
              "version": "3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b",
              "versionType": "git"
            },
            {
              "lessThan": "6774af7cd17be8f0d0f70de3a749d381b4f2e9da",
              "status": "affected",
              "version": "3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b",
              "versionType": "git"
            },
            {
              "lessThan": "2594795fd832f0253826d64ff8976b8ff5fbfe9f",
              "status": "affected",
              "version": "3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b",
              "versionType": "git"
            },
            {
              "lessThan": "6b8897ba0733f88f0360ea48a970f373f9142de0",
              "status": "affected",
              "version": "3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b",
              "versionType": "git"
            },
            {
              "lessThan": "3c6a4b11330fe424557538a98fca9f0a4c5bf313",
              "status": "affected",
              "version": "3fdbd1ce11e5c0d7cafbe44c942c5cad61113d7b",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/openvswitch/actions.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.8"
            },
            {
              "lessThan": "3.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.273",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.224",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.191",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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-\u003eip.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-\u003etransport_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 \u003cTASK\u003e\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"
    }
  ],
  "id": "CVE-2026-99088",
  "lastModified": "2026-10-30T13:21:44.530",
  "metrics": {},
  "published": "2026-10-26T15:16:47.517",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1efa6842e94aa70237446b31fbe2bc16586809c3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2594795fd832f0253826d64ff8976b8ff5fbfe9f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3c6a4b11330fe424557538a98fca9f0a4c5bf313"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/54cb98ed23866205926298621e04169f50665b59"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6774af7cd17be8f0d0f70de3a749d381b4f2e9da"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6b8897ba0733f88f0360ea48a970f373f9142de0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ad4258db21e801a7aae614afca89a2e39283080d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b7b80d204abdc258006f9e17c92b363ab13bb599"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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