CVE-2026-74668

In the Linux kernel, the following vulnerability has been resolved: packet: use consistent hard_header_len in TX_RING send path tpacket_snd() reads dev->hard_header_len independently for skb allocation and header construction in tpacket_fill_skb(). Concurrent netdevice reconfiguration can therefore make the reserved headroom smaller than the amount later pushed, or make copylen - hard_header_len negative. Snapshot hard_header_len once before processing ring frames and use it for the frame limit, headroom allocation, copy length, and skb construction. Pass the snapshot to tpacket_fill_skb(). The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/016763e829cac37b3234eace86fd0a4c560de4a7
https://git.kernel.org/stable/c/21b5953e7494c16a42e6cd8cf110e18d13ae4a6b
https://git.kernel.org/stable/c/27e068d1b35dbec10a3cf268887c94407be4badc
https://git.kernel.org/stable/c/2a73b2c37ee3060a880b53cd24783d93fc7be5f8
https://git.kernel.org/stable/c/9c7e8ff48c377bef18c3d178748aea0575b69ede
https://git.kernel.org/stable/c/d48ea5c9c4c34dc0df621f0e39ed3a16b644621a
https://git.kernel.org/stable/c/d85d2fd54e901637c81d847811e03c662aee13cd
https://git.kernel.org/stable/c/e79f59a8527a49078cfaf8fe8fb5fcefc20c76d2

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-22 16:16

Updated : 2026-08-27 13:18

NVD link : CVE-2026-74668

Mitre link : CVE-2026-74668

CVE.ORG link : CVE-2026-74668

JSON object : View

Products Affected

No product.

CWE

No CWE.

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Concurrent\nnetdevice reconfiguration can therefore make the reserved headroom\nsmaller than the amount later pushed, or make copylen - hard_header_len\nnegative.\n\nSnapshot hard_header_len once before processing ring frames and use it\nfor the frame limit, headroom allocation, copy length, and skb\nconstruction. Pass the snapshot to tpacket_fill_skb().\n\nThe separate SOCK_DGRAM consistency problem between hard_header_len and\nheader_ops->create is not addressed here."}], "lastModified": "2026-08-27T13:18:36.817", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}