CVE-2024-26752

NameCVE-2024-26752
DescriptionIn the Linux kernel, the following vulnerability has been resolved: l2tp: pass correct message length to ip6_append_data l2tp_ip6_sendmsg needs to avoid accounting for the transport header twice when splicing more data into an already partially-occupied skbuff. To manage this, we check whether the skbuff contains data using skb_queue_empty when deciding how much data to append using ip6_append_data. However, the code which performed the calculation was incorrect: ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0; ...due to C operator precedence, this ends up setting ulen to transhdrlen for messages with a non-zero length, which results in corrupted packets on the wire. Add parentheses to correct the calculation in line with the original intent.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)jessie, jessie (lts)3.16.84-1vulnerable
stretch (security)4.9.320-2vulnerable
stretch (lts), stretch4.9.320-3vulnerable
buster4.19.249-2vulnerable
buster (security)4.19.304-1vulnerable
bullseye5.10.209-2vulnerable
bullseye (security)5.10.205-2vulnerable
bookworm6.1.76-1vulnerable
bookworm (security)6.1.85-1fixed
trixie6.6.15-2vulnerable
sid6.7.12-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcejessie(unfixed)end-of-life
linuxsourcestretch(unfixed)end-of-life
linuxsourcebookworm6.1.82-1
linuxsource(unstable)6.7.7-1

Notes

https://git.kernel.org/linus/359e54a93ab43d32ee1bff3c2f9f10cb9f6b6e79 (6.8-rc6)

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