Bug 2535295 (CVE-2026-89879)

Summary: CVE-2026-89879 kernel: media: s2255: bound JPEG frame size before copying into the buffer
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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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's s2255 media driver. The driver fails to properly validate the size of JPEG frames received from a device. A malicious or malfunctioning device can provide an oversized `jpg_size` value, causing a buffer overflow when the data is copied. This could allow an attacker to corrupt memory, potentially leading to a denial of service or other system instability.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-16 11:55:00 UTC 
In the Linux kernel, the following vulnerability has been resolved:

media: s2255: bound JPEG frame size before copying into the buffer

s2255_fillbuff() memcpy()s vc->jpg_size bytes of a captured JPEG/MJPEG
frame into the vb2 plane.  vc->jpg_size is taken verbatim from the
S2255_MARKER_FRAME header the device sends (pdword[4] in save_frame())
and, unlike the frame payload length just above it, is never bounded:

	payload = le32_to_cpu(pdword[3]);
	if (payload > vc->req_image_size)	/* payload is checked ... */
		return -EINVAL;
	vc->pkt_size = payload;
	vc->jpg_size = le32_to_cpu(pdword[4]);	/* ... jpg_size is not */

A malicious or malfunctioning device can therefore report a jpg_size
larger than the destination vb2 plane, and the memcpy() writes past it.
jpg_size is a signed int, so a value with the top bit set also turns
into a huge length.

Reject a frame whose jpg_size is negative or exceeds the plane size
before copying it.
Comment 1 Mauro Matteo Cascella 2026-09-22 15:20:32 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89879.mbox