جزئیات آسیب‌پذیری

In the Linux kernel, the following vulnerability has been resolved: vxlan: use pskb_network_may_pull() in route_shortcircuit() route_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr)) (or ipv6hdr), which checks if bytes are available starting from skb->data. However, in vxlan_xmit(), skb->data points to the MAC header, so skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20) only checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of IP header), leaving the rest of the IP header potentially un-pulled in non-linear frags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled linear buffer length. Fix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to the length check to ensure the full network header is present in the linear buffer.

• https://git.kernel.org/stable/c/c419af4924c1593500a40519730ed98575d04a3e
• https://git.kernel.org/stable/c/6bd0a3a1b5744166946f0c551a6665c3b46b05e4
• https://git.kernel.org/stable/c/214ba43faf106cb06cd3dd30999c5c809c868b53
• https://git.kernel.org/stable/c/42887be7c4cf283cce02cd0fb6411221167c8b6c
• https://git.kernel.org/stable/c/aa0d31376d574ac858a40078431a77127bf04ee4
• https://git.kernel.org/stable/c/ee799977d7941dbfb11049e17edd9eaf4f8820f7
• https://git.kernel.org/stable/c/4f3f96e771a20263635bb5e1307c112d613b4bbd
• https://git.kernel.org/stable/c/26bb2dd0a8839617e2c79ffbbe1923f8e4bab9fb