CVE-2026-64452

Published: July 28, 2026Last modified: July 28, 2026

Description

In 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.

Severity score breakdown

ParameterValue
Base score7.1
Attack VectorADJACENT_NETWORK
Attack complexityHIGH
Privileges requiredNONE
User interactionREQUIRED
ScopeUNCHANGED
ConfidentialityHIGH
Integrity impactHIGH
Availability impactHIGH
VectorCVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Status

ProductReleasePackageStatus
Alpaquita Linux23 LTSlinux-ltsVulnerable (6.1.177-r0)
25 LTSlinux-ltsVulnerable (6.12.95-r0)
Streamlinux-ltsVulnerable (6.18.38-r0)

References

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