Bug 2532428 (CVE-2026-89724)

Summary: CVE-2026-89724 kernel: media: vicodec: fix out-of-bounds write in FWHT encoder
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 `media: vicodec` component. An out-of-bounds write vulnerability exists in the FWHT encoder due to incorrect buffer sizing during video output format handling. This issue allows an attacker to cause corruption of adjacent kernel heap memory, which could lead to system instability or a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Embargoed:

Description OSIDB Bzimport 2026-09-11 22:58:25 UTC 
In the Linux kernel, the following vulnerability has been resolved:

media: vicodec: fix out-of-bounds write in FWHT encoder

vidioc_s_fmt_vid_out() sizes the encoder CAPTURE buffer from the
compressed descriptor pixfmt_fwht, whose sizeimage_mult is 3:
coded_w * coded_h * 3 + sizeof(struct fwht_cframe_hdr). fwht_encode_frame()
encodes one plane per component, and an incompressible plane takes the
FWHT_FRAME_UNENCODED path in encode_plane(), copying the plane verbatim.

For a 4-component pixel format all four planes are full resolution
(width_div == height_div == 1), so a frame that forces every plane
through the unencoded fallback writes
sizeof(struct fwht_cframe_hdr) + 4 * coded_w * coded_h bytes, overrunning
the plane by coded_w * coded_h, which can result in corruption
of adjacent kernel heap memory.

Bump pixfmt_fwht.sizeimage_mult from 3 to 4, matching the largest
components_num among the supported raw formats, so the capture buffer is
always large enough for the unencoded fallback.
Comment 1 gkamathe 2026-09-15 10:23:45 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89724.mbox