CVE-2023-53669

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux7c4e983c4f3cf94fcd879730c6caa877e0768a4d < 7fa93e39fbb0566019c388a8038a4d58552e0910affected
LinuxLinux7c4e983c4f3cf94fcd879730c6caa877e0768a4d < 3c77a377877acbaf03cd7caa21d3644a5dd16301affected
LinuxLinux7c4e983c4f3cf94fcd879730c6caa877e0768a4d < 9cd62f0ba465cf647c7d8c2ca7b0d99ea0c1328faffected
LinuxLinux7c4e983c4f3cf94fcd879730c6caa877e0768a4d < 7e692df3933628d974acb9f5b334d2b3e885e2a6affected
LinuxLinux5.19affected
LinuxLinux0 < 5.19unaffected
LinuxLinux6.1.29 <= 6.1.*unaffected
LinuxLinux6.2.16 <= 6.2.*unaffected
LinuxLinux6.3.3 <= 6.3.*unaffected
LinuxLinux6.4 <= *unaffected

Weaknesses

References