CVE-2024-39490

In the Linux kernel, the following vulnerability has been resolved:

ipv6: sr: fix missing skbuff release in seg6input_core

The seg6input() function is responsible for adding the SRH into a packet, delegating the operation to the seg6inputcore(). This function uses the skbcowhead() to ensure that there is sufficient headroom in the skbuff for accommodating the link-layer header. In the event that the skbcowheader() function fails, the seg6inputcore() catches the error but it does not release the sk_buff, which will result in a memory leak.

This issue was introduced in commit af3b5158b89d ("ipv6: sr: fix BUG due to headroom too small after SRH push") and persists even after commit 7a3f5b0de364 ("netfilter: add netfilter hooks to SRv6 data plane"), where the entire seg6_input() code was refactored to deal with netfilter hooks.

The proposed patch addresses the identified memory leak by requiring the seg6inputcore() function to release the skbuff in the event that skbcow_head() fails.