CVE-2026-80580: fbdev: bound mode sysfs output to the sysfs buffer
fbdev: bound mode sysfs output to the sysfs buffer
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1036.39 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Compensating control
In the fbdev mode sysfs output code, add a size parameter to mode_string(), use scnprintf() so it returns only the bytes actually written, return early when the offset already exceeds the buffer, and make show_modes() stop accumulating once the sysfs buffer is full.
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Linux kernel systems using fbdev are affected when the framebuffer mode list is long enough for the sysfs mode output to exceed the PAGE_SIZE buffer.
What condition triggers the vulnerable behavior?
The issue is triggered while generating sysfs mode output if repeated mode strings cause the accumulated output offset to advance past the sysfs buffer. The flaw results from counting snprintf()’s would-have-written length rather than the bytes actually stored.