CVE-2026-90083

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ife: Only operate on Ethernet frames act_ife encapsulates/decapsulates the original Ethernet header and uses skb->dev->hard_header_len as the length of that header. That is only correct for Ethernet devices: on a device where hard_header_len does not match the L2 header that was actually pulled (PPP reports PPP_HDRLEN while nothing is stripped on ingress), the ingress skb_push()/skb_pull() use the wrong length and can hit skb_under_panic when headroom is tight. IFE is Ethernet-only by design - it builds an outer ethhdr, rewrites h_source/h_dest/h_proto, and calls eth_type_trans() on decode - so instead of trying to make the offsets work for arbitrary link types, simply drop packets that do not carry an Ethernet header. Checking skb->dev->type alone is not enough. We have to cater for a corner case where mirred can redirect an skb from a non-Ethernet device to an Ethernet one, and skb->dev then says nothing about the framing the skb actually has: an skb redirected from ppp0 reaches the target's ingress hook with mac_len 0 and no Ethernet header at all. So at ingress also require mac_len to be ETH_HLEN. On egress mac_len is not maintained, so the device type is all we have; a bogus redirect there yields a malformed frame rather than an out-of-bounds push, and it would be malformed with or without IFE. That corner case is not theoretical - redirecting from ppp0 into a veth that has an ife encode action on its ingress hook panics without this patch: skbuff: skb_under_panic: len:98 put:14 head:ffff88800e410000 data:ffff88800e40fff5 tail:0x57 end:0x640 dev:veth3 kernel BUG at net/core/skbuff.c:214! Call Trace: skb_push (net/core/skbuff.c:224 net/core/skbuff.c:2657) tcf_ife_act (net/sched/act_ife.c:829 net/sched/act_ife.c:874) tc_run (net/core/dev.c:4463) netif_receive_skb (net/core/dev.c:6463 net/core/dev.c:6522) tcf_mirred_to_dev (net/sched/act_mirred.c:248 net/sched/act_mirred.c:328) tcf_mirred_act (net/sched/act_mirred.c:489) tc_run (net/core/dev.c:4463) process_backlog (net/core/dev.c:6728) With Ethernet framing guaranteed, use ETH_HLEN instead of hard_header_len.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-17 17:16:57.707000

Last modified

2026-10-30 13:20:40.657000

View original CVE JSON

{
  "id": "CVE-2026-90083",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-17T17:16:57.707",
  "lastModified": "2026-10-30T13:20:40.657",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_ife: Only operate on Ethernet frames\n\nact_ife encapsulates/decapsulates the original Ethernet header and uses\nskb->dev->hard_header_len as the length of that header. That is only\ncorrect for Ethernet devices: on a device where hard_header_len does not\nmatch the L2 header that was actually pulled (PPP reports PPP_HDRLEN\nwhile nothing is stripped on ingress), the ingress skb_push()/skb_pull()\nuse the wrong length and can hit skb_under_panic when headroom is tight.\n\nIFE is Ethernet-only by design - it builds an outer ethhdr, rewrites\nh_source/h_dest/h_proto, and calls eth_type_trans() on decode - so\ninstead of trying to make the offsets work for arbitrary link types,\nsimply drop packets that do not carry an Ethernet header.\n\nChecking skb->dev->type alone is not enough. We have to cater for a\ncorner case where mirred can redirect an skb from a non-Ethernet device\nto an Ethernet one, and skb->dev then says nothing about the framing the\nskb actually has: an skb redirected from ppp0 reaches the target's ingress\nhook with mac_len 0 and no Ethernet header at all. So at ingress also\nrequire mac_len to be ETH_HLEN. On egress mac_len is not maintained, so\nthe device type is all we have; a bogus redirect there yields a malformed\nframe rather than an out-of-bounds push, and it would be malformed with or\nwithout IFE.\n\nThat corner case is not theoretical - redirecting from ppp0 into a veth\nthat has an ife encode action on its ingress hook panics without this\npatch:\n\n  skbuff: skb_under_panic: len:98 put:14 head:ffff88800e410000\n          data:ffff88800e40fff5 tail:0x57 end:0x640 dev:veth3\n  kernel BUG at net/core/skbuff.c:214!\n  Call Trace:\n   skb_push (net/core/skbuff.c:224 net/core/skbuff.c:2657)\n   tcf_ife_act (net/sched/act_ife.c:829 net/sched/act_ife.c:874)\n   tc_run (net/core/dev.c:4463)\n   netif_receive_skb (net/core/dev.c:6463 net/core/dev.c:6522)\n   tcf_mirred_to_dev (net/sched/act_mirred.c:248 net/sched/act_mirred.c:328)\n   tcf_mirred_act (net/sched/act_mirred.c:489)\n   tc_run (net/core/dev.c:4463)\n   process_backlog (net/core/dev.c:6728)\n\nWith Ethernet framing guaranteed, use ETH_HLEN instead of\nhard_header_len."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/ife/ife.c",
            "net/sched/act_ife.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "295a6e06d21e1f469c9f38b00125a13b60ad4e7c",
              "lessThan": "3c07621770b04f19b67e3af4a24b4d447826fbdd",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "295a6e06d21e1f469c9f38b00125a13b60ad4e7c",
              "lessThan": "b951dd2fd5ede007474fc134ecb5639e1f86f5de",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "295a6e06d21e1f469c9f38b00125a13b60ad4e7c",
              "lessThan": "13dddf87a1f89557920f9b437a21ea0b7225f828",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "295a6e06d21e1f469c9f38b00125a13b60ad4e7c",
              "lessThan": "d218ea7df6eba076171f2d4897a429a31f2139f0",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "295a6e06d21e1f469c9f38b00125a13b60ad4e7c",
              "lessThan": "138b0054021fd7d57bc3eb68b3f4e2bcec037849",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "295a6e06d21e1f469c9f38b00125a13b60ad4e7c",
              "lessThan": "5b483f7791b079bb97d411f1066652ff659207ff",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/ife/ife.c",
            "net/sched/act_ife.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.11",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.11",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.114",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.52",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.6",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/138b0054021fd7d57bc3eb68b3f4e2bcec037849",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/13dddf87a1f89557920f9b437a21ea0b7225f828",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3c07621770b04f19b67e3af4a24b4d447826fbdd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5b483f7791b079bb97d411f1066652ff659207ff",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b951dd2fd5ede007474fc134ecb5639e1f86f5de",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d218ea7df6eba076171f2d4897a429a31f2139f0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}