Bug 2528694 (CVE-2026-80835)

Summary: CVE-2026-80835 kernel: crypto: qcom-rng - Remove crypto_rng interface
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `qcom-rng` driver. This driver, responsible for generating random numbers, allowed two of its interfaces to operate simultaneously without proper synchronization. This oversight could lead to the generation of predictable or non-random values, potentially compromising cryptographic operations and other security features relying on true randomness.
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Description OSIDB Bzimport 2026-09-04 16:24:18 UTC 
In the Linux kernel, the following vulnerability has been resolved:

crypto: qcom-rng - Remove crypto_rng interface

qcom-rng.c exposes the same hardware through two completely separate
interfaces, crypto_rng and hwrng.  However, the implementation of this
is buggy because it permits generation operations from these interfaces
to run concurrently with each other, accessing the same registers.  That
is, qcom_rng_generate() synchronizes with itself but not with
qcom_hwrng_read().  This results in potential repetition of output from
the RNG, output of non-random values, etc.

Fortunately, there's actually no point in hardware RNG drivers
implementing the crypto_rng interface.  It's not actually used by
anything besides the "rng" algorithm type of AF_ALG, which in turn is
not actually used in practice.  Other crypto_rng hardware drivers are
likewise being phased out, leaving just the hwrng support.

Thus, remove it to simplify the code and avoid conflict (and confusion)
with the hwrng interface which is the one that actually matters.
Comment 1 gkamathe 2026-09-08 19:04:12 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80835.mbox