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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2026-80731

net: remove CAP_SYS_RAWIO zero-padding in dev_validate_header

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: net: remove CAP_SYS_RAWIO zero-padding in dev_validate_header dev_validate_header() reads dev->hard_header_len directly when zero-padding short link layer headers for CAP_SYS_RAWIO holders: if (capable(CAP_SYS_RAWIO)) { memset(ll_header + len, 0, dev->hard_header_len - len); return true; } Packet send paths call dev_validate_header() on skbs whose headroom was allocated from an earlier hard_header_len read. If the device is reconfigured so that dev->hard_header_len increases before validation, the memset writes past the reserved buffer, an out-of-bounds write. This out-of-bounds write is masked in some SOCK_RAW paths today because the same concurrent increase can first make skb_push() exceed the reserved headroom and trigger skb_under_panic(). Remove the zero-padding branch before making those hard_header_len reads consistent, so the snapshot fixes do not turn a loud panic into a silent overwrite. This path is only reached for variable length L2 protocols, where len < hard_header_len but len >= min_header_len. No remaining in-tree variable length L2 protocol implements header_ops->validate, and the CAP_SYS_RAWIO bypass that zero-pads and accepts short headers has no real value beyond allowing testing of intentionally malformed input. Drop the CAP_SYS_RAWIO branch. The remaining reads of dev->hard_header_len in dev_validate_header() are comparisons only and have no memory safety impact.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • b5518429e70cd783b8ca52335456172c1a0589f6 to < 53fd7f912c0877647d6a1e1877f5ea8535ee0b4aaffected
  • 2793a23aacbd754dbbb5cb75093deb7e4103bace to < fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6affected
  • 2793a23aacbd754dbbb5cb75093deb7e4103bace to < 8fc9816404166a90ed8d544dc52482fafffb6d9faffected
  • 2793a23aacbd754dbbb5cb75093deb7e4103bace to < b0f92a5731dc82556a9ae005cc35f71ab136307baffected
  • 2793a23aacbd754dbbb5cb75093deb7e4103bace to < 99df6b7a713f96eda206680d100b76e15f9d9b69affected
  • 2793a23aacbd754dbbb5cb75093deb7e4103bace to < 74e035f07f53feca09e2352e77fccb09cad5e208affected
  • 2793a23aacbd754dbbb5cb75093deb7e4103bace to < dbb30dc943a93e083f1e531bfdc6779e57de40d0affected
  • 2793a23aacbd754dbbb5cb75093deb7e4103bace to < fc902f52a02298c7432b2334c0c82a2885a1a8b6affected
  • 2793a23aacbd754dbbb5cb75093deb7e4103bace to < 3b9a324e646d3657a8d9806dfbfe4f3e4066e882affected
  • f58a6c08ebdfa978178bbca78c2ba744a2665912affected
  • 1df16498dfd0d5a129bdf2982d9a08df73e8923daffected
  • 8b8d278aa4de9335682bbd4a3bb619af015c859eaffected
  • 6804052fa9d86e9a512c88b24a5debbfc1a490fcaffected
  • 3.2.80 to < 3.2.81affected
  • 3.16.36 to < 3.17affected
  • 4.1.28 to < 4.2affected
  • 4.4.8 to < 4.5affected
  • 4.5.2 to < 4.6affected

Linux Linux

Default version status: affected

  • 4.6affected
  • 0 to < 4.6unaffected
  • 3.2.81 to ≤ 3.2.*unaffected
  • 5.10.265 to ≤ 5.10.*unaffected
  • 5.15.216 to ≤ 5.15.*unaffected
  • 6.1.183 to ≤ 6.1.*unaffected
  • 6.6.152 to ≤ 6.6.*unaffected
  • 6.12.104 to ≤ 6.12.*unaffected
  • 6.18.45 to ≤ 6.18.*unaffected
  • 7.1.9 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References