Vulnerability details
CVE-2026-74668
packet: use consistent hard_header_len in TX_RING send path
Official description
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 scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.8High | 3.1 | CVEProject cvelistV5 (CNA) (Linux) | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Linux | Linux | 2.6.31 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 ≤ v < 2a73b2c37ee3060a880b53cd24783d93fc7be5f8 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 ≤ v < e79f59a8527a49078cfaf8fe8fb5fcefc20c76d2 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 ≤ v < d85d2fd54e901637c81d847811e03c662aee13cd | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 ≤ v < 9c7e8ff48c377bef18c3d178748aea0575b69ede | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 ≤ v < 27e068d1b35dbec10a3cf268887c94407be4badc | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 ≤ v < d48ea5c9c4c34dc0df621f0e39ed3a16b644621a | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 ≤ v < 21b5953e7494c16a42e6cd8cf110e18d13ae4a6b | CVEProject cvelistV5 (CNA) |
| Linux | Linux | 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 ≤ v < 016763e829cac37b3234eace86fd0a4c560de4a7 | CVEProject cvelistV5 (CNA) |
References and advisories
8- https://git.kernel.org/stable/c/9c7e8ff48c377bef18c3d178748aea0575b69ede
- https://git.kernel.org/stable/c/2a73b2c37ee3060a880b53cd24783d93fc7be5f8
- https://git.kernel.org/stable/c/e79f59a8527a49078cfaf8fe8fb5fcefc20c76d2
- https://git.kernel.org/stable/c/d85d2fd54e901637c81d847811e03c662aee13cd
- https://git.kernel.org/stable/c/016763e829cac37b3234eace86fd0a4c560de4a7
- https://git.kernel.org/stable/c/27e068d1b35dbec10a3cf268887c94407be4badc
- https://git.kernel.org/stable/c/d48ea5c9c4c34dc0df621f0e39ed3a16b644621a
- https://git.kernel.org/stable/c/21b5953e7494c16a42e6cd8cf110e18d13ae4a6b
Details
- Published
- 2026-08-22
- Last updated
- 2026-10-16
- State
- Published
- Assigner (CNA)
- Linux
Exploit prediction (EPSS)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- —