CVE-2026-52998

NameCVE-2026-52998
DescriptionIn the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix potential NULL dereference in ttl check The nf_osf_ttl() function accessed skb->dev to perform a local interface address lookup without verifying that the device pointer was valid. Additionally, the implementation utilized an in_dev_for_each_ifa_rcu loop to match the packet source address against local interface addresses. It assumed that packets from the same subnet should not see a decrement on the initial TTL. A packet might appear it is from the same subnet but it actually isn't especially in modern environments with containers and virtual switching. Remove the device dereference and interface loop. Replace the logic with a switch statement that evaluates the TTL according to the ttl_check.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-4664-1, DLA-4665-1, DLA-4671-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bullseye5.10.223-1vulnerable
bullseye (security)5.10.259-1fixed
bookworm, bookworm (security)6.1.176-1fixed
trixie6.12.94-1fixed
trixie (security)6.12.95-1fixed
forky, sid7.1.3-1fixed
linux-6.1 (PTS)bullseye (security)6.1.176-1~deb11u1fixed

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcebullseye5.10.259-1DLA-4664-1
linuxsourcebookworm6.1.176-1DLA-4665-1
linuxsourcetrixie6.12.94-1
linuxsource(unstable)7.0.10-1
linux-6.1sourcebullseye6.1.176-1~deb11u1DLA-4671-1

Notes

https://git.kernel.org/linus/711987ba281fd806322a7cd244e98e2a81903114 (7.1-rc1)

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