CVE-2023-53669
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
07/10/2025
Last modified:
08/10/2025
Description
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
tcp: fix skb_copy_ubufs() vs BIG TCP<br />
<br />
David Ahern reported crashes in skb_copy_ubufs() caused by TCP tx zerocopy<br />
using hugepages, and skb length bigger than ~68 KB.<br />
<br />
skb_copy_ubufs() assumed it could copy all payload using up to<br />
MAX_SKB_FRAGS order-0 pages.<br />
<br />
This assumption broke when BIG TCP was able to put up to 512 KB per skb.<br />
<br />
We did not hit this bug at Google because we use CONFIG_MAX_SKB_FRAGS=45<br />
and limit gso_max_size to 180000.<br />
<br />
A solution is to use higher order pages if needed.<br />
<br />
v2: add missing __GFP_COMP, or we leak memory.