fkie_cve-2025-40078
Vulnerability from fkie_nvd
Published
2025-10-28 12:15
Modified
2025-10-30 15:05
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Explicitly check accesses to bpf_sock_addr Syzkaller found a kernel warning on the following sock_addr program: 0: r0 = 0 1: r2 = *(u32 *)(r1 +60) 2: exit which triggers: verifier bug: error during ctx access conversion (0) This is happening because offset 60 in bpf_sock_addr corresponds to an implicit padding of 4 bytes, right after msg_src_ip4. Access to this padding isn't rejected in sock_addr_is_valid_access and it thus later fails to convert the access. This patch fixes it by explicitly checking the various fields of bpf_sock_addr in sock_addr_is_valid_access. I checked the other ctx structures and is_valid_access functions and didn't find any other similar cases. Other cases of (properly handled) padding are covered in new tests in a subsequent patch.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4f00858cd9bbbdf67159e28b85a8ca9e77c83622
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6d8b1a21fd5c34622b0c3893c61e4a38d8ba53ec
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6fabca2fc94d33cdf7ec102058983b086293395f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/76e04bbb4296fb6eac084dbfc27e02ccc744db3e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ad8b4fe5617e3c85fc23267f02500c4f3bf0ff69
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cdeafacb4f9ff261a96baef519e29480fd7b1019
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/de44cdc50d2dce8718cb57deddf9cf1be9a7759f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fe9d33f0470350558cb08cecb54cf2267b3a45d2
Impacted products
Vendor Product Version


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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Explicitly check accesses to bpf_sock_addr\n\nSyzkaller found a kernel warning on the following sock_addr program:\n\n    0: r0 = 0\n    1: r2 = *(u32 *)(r1 +60)\n    2: exit\n\nwhich triggers:\n\n    verifier bug: error during ctx access conversion (0)\n\nThis is happening because offset 60 in bpf_sock_addr corresponds to an\nimplicit padding of 4 bytes, right after msg_src_ip4. Access to this\npadding isn\u0027t rejected in sock_addr_is_valid_access and it thus later\nfails to convert the access.\n\nThis patch fixes it by explicitly checking the various fields of\nbpf_sock_addr in sock_addr_is_valid_access.\n\nI checked the other ctx structures and is_valid_access functions and\ndidn\u0027t find any other similar cases. Other cases of (properly handled)\npadding are covered in new tests in a subsequent patch."
    }
  ],
  "id": "CVE-2025-40078",
  "lastModified": "2025-10-30T15:05:32.197",
  "metrics": {},
  "published": "2025-10-28T12:15:42.360",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4f00858cd9bbbdf67159e28b85a8ca9e77c83622"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6d8b1a21fd5c34622b0c3893c61e4a38d8ba53ec"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6fabca2fc94d33cdf7ec102058983b086293395f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/76e04bbb4296fb6eac084dbfc27e02ccc744db3e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ad8b4fe5617e3c85fc23267f02500c4f3bf0ff69"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cdeafacb4f9ff261a96baef519e29480fd7b1019"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/de44cdc50d2dce8718cb57deddf9cf1be9a7759f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fe9d33f0470350558cb08cecb54cf2267b3a45d2"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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