packet: use consistent hard_header_len in non-ring send paths

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-74582
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-21 17:16:44 UTC
Updated2026-08-21 17:16:44 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: packet: use consistent hard_header_len in non-ring send paths packet_snd() reads dev->hard_header_len multiple times while allocating and constructing an skb. Device reconfiguration can change this value concurrently, for example through bonding device type changes. For SOCK_RAW, packet_snd() can save a larger value in reserve and later allocate headroom using a smaller value. Moving skb->data back by reserve then places it before skb->head, and the following copy from userspace can attempt an out-of-bounds write. packet_sendmsg_spkt() has the same issue because it calculates its reservation and header offset from separate reads before dropping the RCU read lock to allocate the skb. Add LL_RESERVED_SPACE_EX() for callers that already saved a header length. Read hard_header_len once in packet_snd() and use it for allocation and construction. In packet_sendmsg_spkt(), preserve the allocation-time value through the device lookup retry. The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here.

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba 91f041451f967cd87ed722a8f43c0b767a64f1a0 git Not specified
CNA Linux Linux affected b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba 9052756290962ffb9a661bcf319e92dedaaedfed git Not specified
CNA Linux Linux affected b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba 5bb10753d428aadfc356a2bfe9acea09c82a62ec git Not specified
CNA Linux Linux affected b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba b06b6fce6d7deaf7238e09b48ce3b1125ff41acd git Not specified
CNA Linux Linux affected b84bbaf7a6c8cca24f8acf25a2c8e46913a947ba 03390aa32e669cc4ecd7d34108e2e1afc13d689d git Not specified
CNA Linux Linux affected d9fb8cc230b2a4757e9fe4f81468f81212d4deaa git Not specified
CNA Linux Linux affected 6190cce26e40bf71c4d375b21eea74bb07b6a0f3 git Not specified
CNA Linux Linux affected 01a658c1b9d4b5393c38d5a92d9112ab1425382a git Not specified
CNA Linux Linux affected 8809ae6747e760e6f1d2453ceb08c9bcc4939766 git Not specified
CNA Linux Linux affected 4.4.133 4.5 semver Not specified
CNA Linux Linux affected 4.9.103 4.10 semver Not specified
CNA Linux Linux affected 4.14.44 4.15 semver Not specified
CNA Linux Linux affected 4.16.12 4.17 semver Not specified
CNA Linux Linux affected 4.17 Not specified
CNA Linux Linux unaffected 4.17 semver Not specified
CNA Linux Linux unaffected 6.6.152 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.104 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.45 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1.9 7.1.* semver Not specified
CNA Linux Linux unaffected 7.2 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/03390aa32e669cc4ecd7d34108e2e1afc13d689d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/9052756290962ffb9a661bcf319e92dedaaedfed 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/b06b6fce6d7deaf7238e09b48ce3b1125ff41acd 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/5bb10753d428aadfc356a2bfe9acea09c82a62ec 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/91f041451f967cd87ed722a8f43c0b767a64f1a0 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

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