{"apiVersion":"1.0","identifier":"CVE-2026-80578","description":"In the Linux kernel, the following vulnerability has been resolved: fbdev: core: Fix pointer desynchronization in fb_io_read() In fb_io_read(), if copy_to_user() performs a partial copy (e.g., due to a faulty user buffer), the loop adjusts the chunk size -c- and updates the remaining -count-. However, the hardware -src- pointer has already been eagerly advanced by the original chunk size. If the loop is allowed to continue, the read will resume from an incorrect, over-advanced offset. Since the remaining -count- was only decremented by the successful bytes, this desynchronization causes the next iterations to execute more hardware reads than originally bounded, eventually leading to out-of-bounds I/O reads. Fix this by breaking out of the loop immediately upon a partial copy_to_user(). A partial copy indicates a faulty user buffer, making subsequent read attempts futile. Breaking out ensures we return the number of successfully read bytes without risking out-of-bounds hardware accesses in subsequent mismatched iterations.","publishedAt":"2026-08-26T15:17:13","lastModifiedAt":"2026-08-27T06:17:43","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-80578","cvssScore":7.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","epssProbability":0.00116,"riskScore":0.74,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-80578","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-80578","en":"https://www.redsauce.net/en/cves/CVE-2026-80578","fr":"https://www.redsauce.net/fr/cves/CVE-2026-80578","pt":"https://www.redsauce.net/pt/cves/CVE-2026-80578","de":"https://www.redsauce.net/de/cves/CVE-2026-80578","sk":"https://www.redsauce.net/sk/cves/CVE-2026-80578","el":"https://www.redsauce.net/el/cves/CVE-2026-80578"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-80578"}}