PT-2026-43900 · Linux · Linux
Published
2026-05-27
·
Updated
2026-05-27
·
CVE-2026-46033
None
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In the Linux kernel, the following vulnerability has been resolved:
crypto: authencesn - reject short ahash digests during instance creation
authencesn requires either a zero authsize or an authsize of at least
4 bytes because the ESN encrypt/decrypt paths always move 4 bytes of
high-order sequence number data at the end of the authenticated data.
While crypto authenc esn setauthsize() already rejects explicit
non-zero authsizes in the range 1..3, crypto authenc esn create()
still copied auth->digestsize into inst->alg.maxauthsize without
validating it. The AEAD core then initialized the tfm's default
authsize from that value.
As a result, selecting an ahash with digest size 1..3, such as
cbcmac(cipher null), exposed authencesn instances whose default
authsize was invalid even though setauthsize() would have rejected the
same value. AF ALG could then trigger the ESN tail handling with a
too-short tag and hit an out-of-bounds access.
Reject authencesn instances whose ahash digest size is in the invalid
non-zero range 1..3 so that no tfm can inherit an unsupported default
authsize.
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Related Identifiers
Affected Products
Linux