Bug 2524462 (CVE-2026-80580)

Summary: CVE-2026-80580 kernel: fbdev: bound mode sysfs output to the sysfs buffer
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: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the `fbdev` component of the Linux kernel. This vulnerability arises because the `mode_string()` function, when generating output for the `sysfs` interface, can write more data than its allocated buffer can hold. An attacker could exploit this by providing a specially crafted input, leading to a buffer overflow. This could result in memory corruption, potentially causing system instability or a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-26 14:57:44 UTC 
In the Linux kernel, the following vulnerability has been resolved:

fbdev: bound mode sysfs output to the sysfs buffer

mode_string() uses snprintf() which can return a value larger than the
remaining buffer space. show_modes() accumulates the return value into i
without checking whether i has reached PAGE_SIZE, causing the offset to
advance past the sysfs buffer if the modelist is long enough.

Add a size parameter to mode_string() and use scnprintf() to return
only the bytes actually written. Add an early return when offset
already exceeds the buffer. In show_modes(), stop accumulating once
the buffer is full.
Comment 1 gkamathe 2026-08-27 09:34:00 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082615-CVE-2026-80580-16d2@gregkh/T