{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-90083",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-90083"
  ],
  "published": "2026-09-17T16:10:40Z",
  "summary": "net/sched: act_ife: Only operate on Ethernet frames",
  "details": "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": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-90083"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d218ea7df6eba076171f2d4897a429a31f2139f0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/138b0054021fd7d57bc3eb68b3f4e2bcec037849"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5b483f7791b079bb97d411f1066652ff659207ff"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-17T16:10:40Z"
  }
}