Description
In the Linux kernel, the following vulnerability has been resolved: net/packet: reset the MAC header on the packet-socket transmit path packet_parse_headers() resets the MAC header only for a SOCK_RAW frame whose socket did not bind a protocol. A protocol-bound SOCK_RAW socket, any SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave skb->mac_header unset here. For frames sent via __dev_queue_xmit() this is harmless: it resets the MAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS path uses dev_direct_xmit(), which does not, so the frame reaches ndo_start_xmit() with the MAC header unset. A driver that reads eth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an out-of-bounds access ~64 KiB past the head -- the same class fixed for one consumer in commit f5089008f90c ("macsec: do not read an unset MAC header in macsec_encrypt()"). packet_parse_headers() runs only on the transmit path, where skb->data points at the start of the L2 header for every packet-socket type regardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied header and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC header unconditionally, mirroring __dev_queue_xmit(), so the frame is anchored on the bypass path too. Found by 0sec (https://0sec.ai) using automated source analysis; verified against source and matched to the macsec KASAN report in f5089008f90c. Compile-tested.
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
75c65772c3d18447d62d3aca5f91b06c16cc25e4 to < 1e43a1d66615f411d427f9df1f46dd049d9e3681affected75c65772c3d18447d62d3aca5f91b06c16cc25e4 to < 4057853a91fb796c4f47c7d1baf1aa085394148eaffected75c65772c3d18447d62d3aca5f91b06c16cc25e4 to < 2610ed4e86a4590234a9d70518c469751c5af231affected75c65772c3d18447d62d3aca5f91b06c16cc25e4 to < b47ba8fe6e1d2df8c92048de5afafd059447dc30affected75c65772c3d18447d62d3aca5f91b06c16cc25e4 to < 284f3e7a3f1a743fdf89e304fd1f19d5ffcff46daffected75c65772c3d18447d62d3aca5f91b06c16cc25e4 to < 971aa7d99242bbf09513e27b7a243f0b29ff23aeaffected75c65772c3d18447d62d3aca5f91b06c16cc25e4 to < fdd4d7d52358a58e351dd9d82530c04eba8ccd7aaffected75c65772c3d18447d62d3aca5f91b06c16cc25e4 to < c2707480cfbf19c7619acc9c089d17f20869821faffected
Linux Linux
Default version status: affected
5.1affected0 to < 5.1unaffected5.10.265 to ≤ 5.10.*unaffected5.15.216 to ≤ 5.15.*unaffected6.1.183 to ≤ 6.1.*unaffected6.6.152 to ≤ 6.6.*unaffected6.12.104 to ≤ 6.12.*unaffected6.18.45 to ≤ 6.18.*unaffected7.1.9 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/1e43a1d66615f411d427f9df1f46dd049d9e3681 ↗
- https://git.kernel.org/stable/c/4057853a91fb796c4f47c7d1baf1aa085394148e ↗
- https://git.kernel.org/stable/c/2610ed4e86a4590234a9d70518c469751c5af231 ↗
- https://git.kernel.org/stable/c/b47ba8fe6e1d2df8c92048de5afafd059447dc30 ↗
- https://git.kernel.org/stable/c/284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d ↗
- https://git.kernel.org/stable/c/971aa7d99242bbf09513e27b7a243f0b29ff23ae ↗
- https://git.kernel.org/stable/c/fdd4d7d52358a58e351dd9d82530c04eba8ccd7a ↗
- https://git.kernel.org/stable/c/c2707480cfbf19c7619acc9c089d17f20869821f ↗