CVE-2024-36971

NameCVE-2024-36971
DescriptionIn the Linux kernel, the following vulnerability has been resolved: net: fix __dst_negative_advice() race __dst_negative_advice() does not enforce proper RCU rules when sk->dst_cache must be cleared, leading to possible UAF. RCU rules are that we must first clear sk->sk_dst_cache, then call dst_release(old_dst). Note that sk_dst_reset(sk) is implementing this protocol correctly, while __dst_negative_advice() uses the wrong order. Given that ip6_negative_advice() has special logic against RTF_CACHE, this means each of the three ->negative_advice() existing methods must perform the sk_dst_reset() themselves. Note the check against NULL dst is centralized in __dst_negative_advice(), there is no need to duplicate it in various callbacks. Many thanks to Clement Lecigne for tracking this issue. This old bug became visible after the blamed commit, using UDP sockets.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-3840-1, DSA-5730-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bullseye5.10.223-1fixed
bullseye (security)5.10.226-1fixed
bookworm6.1.106-3fixed
bookworm (security)6.1.112-1fixed
trixie6.11.5-1fixed
sid6.11.6-1fixed

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcebuster4.19.316-1DLA-3840-1
linuxsourcebullseye5.10.221-1DSA-5730-1
linuxsourcebookworm6.1.94-1
linuxsource(unstable)6.9.7-1

Notes

https://git.kernel.org/linus/92f1655aa2b2294d0b49925f3b875a634bd3b59e (6.10-rc2)

Search for package or bug name: Reporting problems