CVE-2026-63872
CVE-2026-63872CVE-2026-63872
Description
In the Linux kernel, the following vulnerability has been resolved:
esp: fix page frag reference leak on skb_to_sgvec failure
In esp_output_tail(), when esp->inplace is false, the old skb page frags
are replaced with a new page from the xfrm page_frag cache. The source
scatterlist (sg) is built from the old frags before the replacement, and
esp_ssg_unref() is responsible for releasing the old page references
after the crypto operation completes.
However, if the second skb_to_sgvec() call (which builds the destination
scatterlist from the new page) fails, the code jumps to error_free which
only calls kfree(tmp). The old page frag references captured in the
source scatterlist are never released:
1. sg[] is built from old frags via skb_to_sgvec() (no extra get_page)
2. nr_frags is set to 1 and frag[0] is replaced with the new page
3. Second skb_to_sgvec() fails -> goto error_free
4. kfree(tmp) frees the sg[] memory but old frags are not unref'd
5. kfree_skb() only releases f
Scoring
| Last modified | 2026-07-19 |