Bug 2536203 (CVE-2026-90405)

Summary: CVE-2026-90405 kernel: media: stm32: dcmi: fix some error handling bugs in probe()
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 `media: stm32: dcmi` component of the Linux kernel. Improper error handling in the `probe()` function can lead to a null pointer dereference. This issue occurs because `dma_release_channel()` is called before the `dcmi->dma_chan` variable is properly assigned, potentially allowing a local attacker to cause a denial of service (DoS) due to system instability or crashes. Additionally, other error handling bugs could result in memory leaks.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-17 16:50:36 UTC
In the Linux kernel, the following vulnerability has been resolved:

media: stm32: dcmi: fix some error handling bugs in probe()

There are a few issues here:

1) After we assign:
        chan = dma_request_chan(&pdev->dev, "tx");
   Then the error paths need to clean up before returning.  The first
   error path does a direct return.
2) The error paths check "dcmi->mdma_chan" but that is not assigned
   until later so it results in memory leaks.  Test "mdma_chan"
   instead.
3) The error handling calls dma_release_channel(dcmi->dma_chan) before
   "dcmi->dma_chan" has been assigned which leads to a NULL pointer
   dereference.  Use the "chan" variable instead.

I also moved the call to dma_release_channel() after the call to
dma_release_channel() so it mirrors the allocation code better.