Bug 2536648 (CVE-2026-90427)

Summary: CVE-2026-90427 kernel: iommu/tegra241-cmdqv: Don't fall back to a freed smmu after devm_krealloc()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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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Doc Text:
A flaw was found in the Linux kernel's `iommu/tegra241-cmdqv` driver. During the `__tegra241_cmdqv_probe()` function, a memory reallocation operation can free an existing memory region. If this reallocation fails, a subsequent fallback path attempts to access the previously freed memory. This 'use-after-free' vulnerability can lead to system instability or a denial of service (DoS) condition.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-17 19:02:09 UTC 
In the Linux kernel, the following vulnerability has been resolved:

iommu/tegra241-cmdqv: Don't fall back to a freed smmu after devm_krealloc()

__tegra241_cmdqv_probe() uses devm_krealloc() to grow @smmu into the larger
tegra241_cmdqv, which frees the original @smmu once it relocates. A failure
after that returned NULL, and the caller then dereferenced the freed @smmu
on its fallback path.

Return an int and take @smmu by reference instead, then update *smmu to the
reallocated pointer after devm_krealloc() succeeds, so the caller and its
fallback path both use the live @smmu rather than the freed original.
Comment 1 gkamathe 2026-09-21 14:14:59 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90427.mbox