Description

In the Linux kernel, the following vulnerability has been resolved: tap: free page on error paths in tap_get_user_xdp() tap_get_user_xdp() rejects a frame shorter than ETH_HLEN with -EINVAL, and returns -ENOMEM when build_skb() fails. Both paths jump to the err label without freeing the page that vhost_net_build_xdp() allocated for the frame. tap_sendmsg() discards the per-buffer return value and always returns 0, so vhost_tx_batch() takes the success path and never frees the page; each rejected frame in a batch leaks one page-frag chunk. Free the page on both error paths, before the skb is built. This is the tap counterpart of the same leak in tun_xdp_one().

References 8

• git.kernel.org https://git.kernel.org/stable/c/18a84c35842e19cd3c5534d8cee73d31863f696d
• git.kernel.org https://git.kernel.org/stable/c/3bcf7aec6a9d16438f2cec29f5d7c8d5b8edf9b2
• git.kernel.org https://git.kernel.org/stable/c/3f52a86a482a69294c50a5a2a097bd6f4104990a
• git.kernel.org https://git.kernel.org/stable/c/8d03e65eb6cfbffec471a6b65416f93679bf3286
• git.kernel.org https://git.kernel.org/stable/c/d30aac0fa00ca0afc3e08174cf7f974a66bdcf05
• git.kernel.org https://git.kernel.org/stable/c/d68eab61944a9b0826fa2e954e42db1aa3201b7a
• git.kernel.org https://git.kernel.org/stable/c/e27c17346628cb56843a83f93ac63c314c00f388
• git.kernel.org https://git.kernel.org/stable/c/f979971835dddbca86cf99e3b2e2b94a408a1ab2

Remediation