Description
In the Linux kernel, the following vulnerability has been resolved:
macsec: don't read an unset MAC header in macsec_encrypt()
macsec_encrypt() reads the Ethernet header via eth_hdr(skb) (skb->head + skb->mac_header) to memmove() the 12 source/destination MAC bytes forward and make room for the SecTAG.
On the AF_PACKET SOCK_RAW + PACKET_QDISC_BYPASS transmit path the skb reaches the macsec ndo_start_xmit() with the MAC header unset, so eth_hdr(skb) resolves to skb->head + (u16)~0 and the read is out of bounds: a 12-byte heap over-read that is also emitted on the wire as the frame's outer source/destination MAC. KASAN reports a slab-out-of-bounds read in macsec_start_xmit() on 6.0; on current mainline a CONFIG_DEBUG_NET build flags it as an unset mac header in skb_mac_header().
On the TX path the L2 header is at skb->data, so use skb_eth_hdr(), added by commit 96cc4b69581d ("macvlan: do not assume mac_header is set in macvlan_broadcast()") for exactly this purpose.
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:HWeakness enumeration
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= c09440f7dcb304002dfced8c0fea289eb25f2da0, < b6cec6187b8632423cd99a94fd5e5ba165fa2a33; >= c09440f7dcb304002dfced8c0fea289eb25f2da0, < 3adea1b1c04b57e08a5c12a1f42483760581ce61; >= c09440f7dcb304002dfced8c0fea289eb25f2da0, < dc9ffa1905e72f026d080880a2e4cfc42aa91000; >= c09440f7dcb304002dfced8c0fea289eb25f2da0, < f21fa533a3ed15ada74106aac4b9ddd078fc6b7a; >= c09440f7dcb304002dfced8c0fea289eb25f2da0, < e17a42199824973cd8212e95b21ffadf4114a21b; >= c09440f7dcb304002dfced8c0fea289eb25f2da0, < 2cf10d042562283ff4ae97c02d0993d4f1b5ea29; >= c09440f7dcb304002dfced8c0fea289eb25f2da0, < c39087ad0b97fc11a3b058dfc8db9fd370762cb9; >= c09440f7dcb304002dfced8c0fea289eb25f2da0, < f5089008f90c0a7c5520dff3934e0af00adf322d |
| Linux | Linux | 4.6 |
References
- https://git.kernel.org/stable/c/2cf10d042562283ff4ae97c02d0993d4f1b5ea29
- https://git.kernel.org/stable/c/3adea1b1c04b57e08a5c12a1f42483760581ce61
- https://git.kernel.org/stable/c/b6cec6187b8632423cd99a94fd5e5ba165fa2a33
- https://git.kernel.org/stable/c/c39087ad0b97fc11a3b058dfc8db9fd370762cb9
- https://git.kernel.org/stable/c/dc9ffa1905e72f026d080880a2e4cfc42aa91000
- https://git.kernel.org/stable/c/e17a42199824973cd8212e95b21ffadf4114a21b
- https://git.kernel.org/stable/c/f21fa533a3ed15ada74106aac4b9ddd078fc6b7a
- https://git.kernel.org/stable/c/f5089008f90c0a7c5520dff3934e0af00adf322d
Timeline
- Published
- Aug 15, 2026
- Last modified
- Oct 19, 2026
- NVD status
- Received