CVE-2022-49872 (GCVE-0-2022-49872)
Vulnerability from cvelistv5
Published
2025-05-01 14:10
Modified
2026-08-05 08:56
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: net: gso: fix panic on frag_list with mixed head alloc types Since commit 3dcbdb134f32 ("net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list"), it is allowed to change gso_size of a GRO packet. However, that commit assumes that "checking the first list_skb member suffices; i.e if either of the list_skb members have non head_frag head, then the first one has too". It turns out this assumption does not hold. We've seen BUG_ON being hit in skb_segment when skbs on the frag_list had differing head_frag with the vmxnet3 driver. This happens because __netdev_alloc_skb and __napi_alloc_skb can return a skb that is page backed or kmalloced depending on the requested size. As the result, the last small skb in the GRO packet can be kmalloced. There are three different locations where this can be fixed: (1) We could check head_frag in GRO and not allow GROing skbs with different head_frag. However, that would lead to performance regression on normal forward paths with unmodified gso_size, where !head_frag in the last packet is not a problem. (2) Set a flag in bpf_skb_net_grow and bpf_skb_net_shrink indicating that NETIF_F_SG is undesirable. That would need to eat a bit in sk_buff. Furthermore, that flag can be unset when all skbs on the frag_list are page backed. To retain good performance, bpf_skb_net_grow/shrink would have to walk the frag_list. (3) Walk the frag_list in skb_segment when determining whether NETIF_F_SG should be cleared. This of course slows things down. This patch implements (3). To limit the performance impact in skb_segment, the list is walked only for skbs with SKB_GSO_DODGY set that have gso_size changed. Normal paths thus will not hit it. We could check only the last skb but since we need to walk the whole list anyway, let's stay on the safe side.
References
Impacted products
Vendor Product Version
Linux Linux Version: 162a5a8c3aff15c449e6b38355cdf80ab4f77a5a
Version: 55fb612bef7fd237fb70068e2b6ff1cd1543a8ef
Version: 821302dd0c51d29269ef73a595bdff294419e2cd
Version: 3dcbdb134f329842a38f0e6797191b885ab00a00
Version: 3dcbdb134f329842a38f0e6797191b885ab00a00
Version: 3dcbdb134f329842a38f0e6797191b885ab00a00
Version: 3dcbdb134f329842a38f0e6797191b885ab00a00
Version: 3dcbdb134f329842a38f0e6797191b885ab00a00
Version: 92984818ff8cfd97311a5e0ac27f148a00df2b54
Version: 4.9.194   ≤
Version: 4.14.145   ≤
Version: 4.19.74   ≤
Version: 5.2.16   ≤
Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/core/skbuff.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5876b7f249a1ecbbcc8e35072c3828d6526d1c3a",
              "status": "affected",
              "version": "162a5a8c3aff15c449e6b38355cdf80ab4f77a5a",
              "versionType": "git"
            },
            {
              "lessThan": "0a9f56e525ea871d3950b90076912f5c7494f00f",
              "status": "affected",
              "version": "55fb612bef7fd237fb70068e2b6ff1cd1543a8ef",
              "versionType": "git"
            },
            {
              "lessThan": "bd5362e58721e4d0d1a37796593bd6e51536ce7a",
              "status": "affected",
              "version": "821302dd0c51d29269ef73a595bdff294419e2cd",
              "versionType": "git"
            },
            {
              "lessThan": "65ad047fd83502447269fda8fd26c99077a9af47",
              "status": "affected",
              "version": "3dcbdb134f329842a38f0e6797191b885ab00a00",
              "versionType": "git"
            },
            {
              "lessThan": "50868de7dc4e7f0fcadd6029f32bf4387c102ee6",
              "status": "affected",
              "version": "3dcbdb134f329842a38f0e6797191b885ab00a00",
              "versionType": "git"
            },
            {
              "lessThan": "ad25a115f50800c6847e0d841c5c7992a9f7c1b3",
              "status": "affected",
              "version": "3dcbdb134f329842a38f0e6797191b885ab00a00",
              "versionType": "git"
            },
            {
              "lessThan": "598d9e30927b15731e83797fbd700ecf399f42dd",
              "status": "affected",
              "version": "3dcbdb134f329842a38f0e6797191b885ab00a00",
              "versionType": "git"
            },
            {
              "lessThan": "9e4b7a99a03aefd37ba7bb1f022c8efab5019165",
              "status": "affected",
              "version": "3dcbdb134f329842a38f0e6797191b885ab00a00",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "92984818ff8cfd97311a5e0ac27f148a00df2b54",
              "versionType": "git"
            },
            {
              "lessThan": "4.9.334",
              "status": "affected",
              "version": "4.9.194",
              "versionType": "semver"
            },
            {
              "lessThan": "4.14.300",
              "status": "affected",
              "version": "4.14.145",
              "versionType": "semver"
            },
            {
              "lessThan": "4.19.267",
              "status": "affected",
              "version": "4.19.74",
              "versionType": "semver"
            },
            {
              "lessThan": "5.3",
              "status": "affected",
              "version": "5.2.16",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/core/skbuff.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.3"
            },
            {
              "lessThan": "5.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.9.*",
              "status": "unaffected",
              "version": "4.9.334",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.14.*",
              "status": "unaffected",
              "version": "4.14.300",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.19.*",
              "status": "unaffected",
              "version": "4.19.267",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.225",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.155",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.79",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.0.*",
              "status": "unaffected",
              "version": "6.0.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.9.334",
                  "versionStartIncluding": "4.9.194",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.14.300",
                  "versionStartIncluding": "4.14.145",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.19.267",
                  "versionStartIncluding": "4.19.74",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.4.225",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.155",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.79",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.0.9",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.2.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gso: fix panic on frag_list with mixed head alloc types\n\nSince commit 3dcbdb134f32 (\"net: gso: Fix skb_segment splat when\nsplitting gso_size mangled skb having linear-headed frag_list\"), it is\nallowed to change gso_size of a GRO packet. However, that commit assumes\nthat \"checking the first list_skb member suffices; i.e if either of the\nlist_skb members have non head_frag head, then the first one has too\".\n\nIt turns out this assumption does not hold. We\u0027ve seen BUG_ON being hit\nin skb_segment when skbs on the frag_list had differing head_frag with\nthe vmxnet3 driver. This happens because __netdev_alloc_skb and\n__napi_alloc_skb can return a skb that is page backed or kmalloced\ndepending on the requested size. As the result, the last small skb in\nthe GRO packet can be kmalloced.\n\nThere are three different locations where this can be fixed:\n\n(1) We could check head_frag in GRO and not allow GROing skbs with\n    different head_frag. However, that would lead to performance\n    regression on normal forward paths with unmodified gso_size, where\n    !head_frag in the last packet is not a problem.\n\n(2) Set a flag in bpf_skb_net_grow and bpf_skb_net_shrink indicating\n    that NETIF_F_SG is undesirable. That would need to eat a bit in\n    sk_buff. Furthermore, that flag can be unset when all skbs on the\n    frag_list are page backed. To retain good performance,\n    bpf_skb_net_grow/shrink would have to walk the frag_list.\n\n(3) Walk the frag_list in skb_segment when determining whether\n    NETIF_F_SG should be cleared. This of course slows things down.\n\nThis patch implements (3). To limit the performance impact in\nskb_segment, the list is walked only for skbs with SKB_GSO_DODGY set\nthat have gso_size changed. Normal paths thus will not hit it.\n\nWe could check only the last skb but since we need to walk the whole\nlist anyway, let\u0027s stay on the safe side."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - GRO builds the fragile frag_list skb from remote TCP/UDP packets on ingress; with a realistic TC/LWT BPF NAT64 or adjust_room datapath (the path this bug was fixed for, and observed with vmxnet3), egress skb_segment runs on those packets, so an unauthenticated remote peer triggers the panic by sending traffic through the gateway.\nAC:L - The attacker controls segment sizes so GRO\u2019s last member is small enough to be kmalloced (!head_frag) while earlier members are page-backed, and once SKB_GSO_DODGY is set by the in-path BPF helper the incomplete first-only check fails and BUG_ON fires deterministically\u2014no race or uncontrollable memory layout.\nPR:N - In the highest-impact deployment the administrator has already attached the BPF/NAT datapath; the attacker needs no host account or capability and only sends unauthenticated packets on the wire.\nUI:N - Packet reception, GRO, BPF gso_size mangling, and egress GSO segmentation all run automatically in softirq on an up interface with no separate victim action.\nS:U - The BUG_ON/oops/panic is confined to the host kernel processing the packets and does not cross a VM, IOMMU, or other security-authority boundary.\nC:N - The failure is an intentional BUG_ON(!list_skb-\u003ehead_frag) in skb_segment before any page-desc conversion or data copy from the bad head, so there is no OOB read or info-disclosure primitive.\nI:N - The assertion aborts before skb_head_frag_to_page_desc would treat a kmalloc head as a page fragment, so there is no OOB/UAF write or control-flow hijack primitive\u2014only the panic.\nA:H - Hitting BUG_ON in skb_segment from the NAPI/softirq GSO path oopses/panics the host (as reported with vmxnet3), and it can be re-triggered by resending traffic\u2014full availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T08:56:29.682Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/5876b7f249a1ecbbcc8e35072c3828d6526d1c3a"
        },
        {
          "url": "https://git.kernel.org/stable/c/0a9f56e525ea871d3950b90076912f5c7494f00f"
        },
        {
          "url": "https://git.kernel.org/stable/c/bd5362e58721e4d0d1a37796593bd6e51536ce7a"
        },
        {
          "url": "https://git.kernel.org/stable/c/65ad047fd83502447269fda8fd26c99077a9af47"
        },
        {
          "url": "https://git.kernel.org/stable/c/50868de7dc4e7f0fcadd6029f32bf4387c102ee6"
        },
        {
          "url": "https://git.kernel.org/stable/c/ad25a115f50800c6847e0d841c5c7992a9f7c1b3"
        },
        {
          "url": "https://git.kernel.org/stable/c/598d9e30927b15731e83797fbd700ecf399f42dd"
        },
        {
          "url": "https://git.kernel.org/stable/c/9e4b7a99a03aefd37ba7bb1f022c8efab5019165"
        }
      ],
      "title": "net: gso: fix panic on frag_list with mixed head alloc types",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2022-49872",
    "datePublished": "2025-05-01T14:10:22.402Z",
    "dateReserved": "2025-05-01T14:05:17.238Z",
    "dateUpdated": "2026-08-05T08:56:29.682Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.