{"id":"CVE-2026-53402","revision":"6a72548e82144bb1a292be625acf69d6","records":[{"revision":"6a72548e82144bb1a292be625acf69d6","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-53402","aliases":[],"title":"fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font()\n\nWhen fbcon_do_set_font() fails (e.g., due to a memory allocation failure\ninside vc_resize() under heavy memory pressure), it jumps to the `err_out`\nlabel to roll back the console state. However, the current rollback logic\nforgets to restore the `hi_font` state, leading to a severe state machine\ncorruption.\n\nEarlier in the function, `set_vc_hi_font()` might be called to change\n`vc->vc_hi_font_mask` and mutate the screen buffer. If `vc_resize()`\nsubsequently fails, the `err_out` path restores `vc_font.charcount`\nbut entirely skips rolling back the `vc_hi_font_mask` and the screen\nbuffer.\n\nThis mismatch leaves the terminal in a desynchronized state. Because\n`vc_hi_font_mask` remains set, the VT subsystem will still accept\ncharacter indices greater than 255 from userspace and write them to the\nscreen buffer. Subsequent rendering calls (e.g., `fbcon_putcs()`) will\nthen use these inflated indices to access the reverted, 256-character\nfont array, leading to a deterministic out-of-bounds read and potential\nkernel memory disclosure.\n\nFix this by adding the missing rollback logic for the `hi_font` mask\nand screen buffer in the error path.","state":0,"publishedAt":"2026-07-19T12:02:01.795+00:00","modifiedAt":"2026-10-19T20:07:47.003+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/video/fbdev/core/fbcon.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"868749a7456dc48e93887a8474194e2ee6d6c21f\",\n                            \"lessThan\": \"cb016bcb40c81e7b19c4ae6143babb366dae8e20\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ebd6f886aa2447fcfcdce5450c9e1028e1d681bb\",\n                            \"lessThan\": \"ac562193c36696513ae196171892e9338475c4bc\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24\",\n                            \"lessThan\": \"3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24\",\n                            \"lessThan\": \"a7a526fbc847f07ad3a503c7382189be5ab68574\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24\",\n                            \"lessThan\": \"b5bb2c696e140c399cb874def2feedf61dee27d6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24\",\n                            \"lessThan\": \"076b1aa65f77a49bce5a48a4a55a397cfcafa2b8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24\",\n                            \"lessThan\": \"39815715cbcfabb16fc8c5f4a23deeda20f5df62\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24\",\n                            \"lessThan\": \"8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f08ccb792d3eaf1dc62d8cbf6a30d6522329f660\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5.10.249\",\n                            \"lessThan\": \"5.10.261\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.64\",\n                            \"lessThan\": \"5.15.212\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.19.6\",\n                            \"lessThan\": \"5.20\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/video/fbdev/core/fbcon.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.0\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.96\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.39\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.3\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","score":7.1,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/cb016bcb40c81e7b19c4ae6143babb366dae8e20","https://git.kernel.org/stable/c/ac562193c36696513ae196171892e9338475c4bc","https://git.kernel.org/stable/c/3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5","https://git.kernel.org/stable/c/a7a526fbc847f07ad3a503c7382189be5ab68574","https://git.kernel.org/stable/c/b5bb2c696e140c399cb874def2feedf61dee27d6","https://git.kernel.org/stable/c/076b1aa65f77a49bce5a48a4a55a397cfcafa2b8","https://git.kernel.org/stable/c/39815715cbcfabb16fc8c5f4a23deeda20f5df62","https://git.kernel.org/stable/c/8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53402","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-53402","identifiers":["CVE-2026-53402"]},"retained":false,"historicalAffected":[]}],"coverage":[]}