CVE-2026-64452

NameCVE-2026-64452
DescriptionIn the Linux kernel, the following vulnerability has been resolved: 6lowpan: fix NHC entry use-after-free on error path lowpan_nhc_do_uncompression() looks up an NHC descriptor while holding lowpan_nhc_lock. If the descriptor has no uncompress callback, the error path drops the lock before printing nhc->name. lowpan_nhc_del() removes descriptors under the same lock and then relies on synchronize_net() before the owning module can be unloaded. That only waits for net RX RCU readers. lowpan_header_decompress() is also exported and can be reached from callers that are not necessarily covered by the net core RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive path. This leaves a race where one task drops lowpan_nhc_lock in the error path, another task unregisters and frees the matching descriptor after synchronize_net() returns, and the first task then dereferences nhc->name for the warning. With the post-unlock window widened, KASAN reports: BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220 Read of size 8 lowpan_nhc_do_uncompression lowpan_header_decompress Fix this by printing the warning before dropping lowpan_nhc_lock, so the descriptor name is read while unregister is still excluded. The malformed packet is still rejected with -ENOTSUPP.
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-4717-1, DLA-4720-1, DLA-4723-1, DLA-4724-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bullseye5.10.223-1vulnerable
bullseye (security)5.10.262-1fixed
bookworm6.1.176-1vulnerable
bookworm (security)6.1.180-1fixed
trixie6.12.94-1vulnerable
trixie (security)6.12.101-1fixed
forky7.1.7-1fixed
sid7.1.8-1fixed
linux-6.1 (PTS)bullseye (security)6.1.180-1~deb11u1fixed
linux-6.12 (PTS)bookworm (security)6.12.100-1~deb12u1fixed

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcebullseye5.10.262-1DLA-4717-1
linuxsourcebookworm6.1.180-1DLA-4720-1
linuxsourcetrixie6.12.96-1
linuxsource(unstable)7.1.4-1
linux-6.1sourcebullseye6.1.180-1~deb11u1DLA-4723-1
linux-6.12sourcebookworm6.12.100-1~deb12u1DLA-4724-1

Notes

https://git.kernel.org/linus/1720db928e5a58ca7d75ac1d514c3b73fd7061a7 (7.2-rc1)

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