CVE-2023-53669: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: tcp: fix skb_copy_ubufs() vs BIG TCP David Ahern reported crashes in skb_copy_ubufs() caused by TCP tx zerocopy using hugepages, and skb length bigger than ~68 KB. skb_copy_ubufs() assumed it could copy all payload using up to MAX_SKB_FRAGS order-0 pages. This assumption broke when BIG TCP was able to put up to 512 KB per skb. We did not hit this bug at Google because we use CONFIG_MAX_SKB_FRAGS=45 and limit gso_max_size to 180000. A solution is to use higher order pages if needed. v2: add missing __GFP_COMP, or we leak memory.

Affected products

• Linux Linux Kernel: from 5.19, before 6.1.29 (fixed in 6.1.29); from 6.2, before 6.2.16 (fixed in 6.2.16); from 6.3, before 6.3.3 (fixed in 6.3.3)

Published 2025-10-07. Last modified 2026-08-04.