CVE-2026-43497

{"id": "CVE-2026-43497", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.3, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.3}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "7433914efd584b22bb49d3e1eee001f5d0525ecd", "lessThan": "60f711cfd580f86fea8284146ac133804e728f9a", "versionType": "git"}, {"status": "affected", "version": "7433914efd584b22bb49d3e1eee001f5d0525ecd", "lessThan": "5931f5651ee32bd41b3323256b31fcc8e71336ed", "versionType": "git"}, {"status": "affected", "version": "7433914efd584b22bb49d3e1eee001f5d0525ecd", "lessThan": "e3d9865dacd7435b8465848428210d0f0c673311", "versionType": "git"}, {"status": "affected", "version": "7433914efd584b22bb49d3e1eee001f5d0525ecd", "lessThan": "4f312c30f0368e8d2a76aa650dff73f23490b5e7", "versionType": "git"}, {"status": "affected", "version": "7433914efd584b22bb49d3e1eee001f5d0525ecd", "lessThan": "18dd358de72d57993422cbb5dfb29ccd74efe192", "versionType": "git"}, {"status": "affected", "version": "7433914efd584b22bb49d3e1eee001f5d0525ecd", "lessThan": "da9b065cedfd3b574f229d5be594e6aa47a27ae6", "versionType": "git"}, {"status": "affected", "version": "7433914efd584b22bb49d3e1eee001f5d0525ecd", "lessThan": "a2c53a3822ee26e8d758071815b9ed3bf6669fc1", "versionType": "git"}, {"status": "affected", "version": "7433914efd584b22bb49d3e1eee001f5d0525ecd", "lessThan": "8de779dc40d35d39fa07387b6f921eb11df0f511", "versionType": "git"}], "programFiles": ["drivers/video/fbdev/udlfb.c", "include/video/udlfb.h"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.19"}, {"status": "unaffected", "version": "0", "lessThan": "4.19", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.258", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.209", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.175", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.140", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.88", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.30", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.0.7", "versionType": "semver", "lessThanOrEqual": "7.0.*"}, {"status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/video/fbdev/udlfb.c", "include/video/udlfb.h"], "defaultStatus": "affected"}]}], "published": "2026-05-21T13:16:19.090", "references": [{"url": "https://git.kernel.org/stable/c/18dd358de72d57993422cbb5dfb29ccd74efe192", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/4f312c30f0368e8d2a76aa650dff73f23490b5e7", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/5931f5651ee32bd41b3323256b31fcc8e71336ed", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/60f711cfd580f86fea8284146ac133804e728f9a", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8de779dc40d35d39fa07387b6f921eb11df0f511", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a2c53a3822ee26e8d758071815b9ed3bf6669fc1", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/da9b065cedfd3b574f229d5be594e6aa47a27ae6", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e3d9865dacd7435b8465848428210d0f0c673311", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free\n\ndlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages\nto userspace but sets no vm_ops on the VMA. This means the kernel cannot\ntrack active mmaps. When dlfb_realloc_framebuffer() replaces the backing\nbuffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated.\nOn USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages\nwhile userspace PTEs still reference them, resulting in a use-after-free:\nthe process retains read/write access to freed kernel pages.\n\nAdd vm_operations_struct with open/close callbacks that maintain an\natomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(),\ncheck mmap_count and return -EBUSY if the buffer is currently mapped,\npreventing buffer replacement while userspace holds stale PTEs.\n\nTested with PoC using dummy_hcd + raw_gadget USB device emulation."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nfbdev: udlfb: a\u00f1adir vm_ops a dlfb_ops_mmap para prevenir el uso despu\u00e9s de liberaci\u00f3n\n\ndlfb_ops_mmap() utiliza remap_pfn_range() para mapear p\u00e1ginas de framebuffer de vmalloc al espacio de usuario, pero no establece vm_ops en el VMA. Esto significa que el kernel no puede rastrear mmaps activos. Cuando dlfb_realloc_framebuffer() reemplaza el b\u00fafer de respaldo a trav\u00e9s de FBIOPUT_VSCREENINFO, los PTEs de mmap existentes no se invalidan. Al desconectar el USB, dlfb_ops_destroy() llama a vfree() en las p\u00e1ginas antiguas mientras los PTEs del espacio de usuario a\u00fan las referencian, lo que resulta en un uso despu\u00e9s de liberaci\u00f3n: el proceso retiene acceso de lectura/escritura a p\u00e1ginas del kernel liberadas.\n\nA\u00f1adir vm_operations_struct con callbacks de apertura/cierre que mantienen un mmap_count at\u00f3mico en la estructura dlfb_data. En dlfb_realloc_framebuffer(), comprobar mmap_count y devolver -EBUSY si el b\u00fafer est\u00e1 actualmente mapeado, lo que previene el reemplazo del b\u00fafer mientras el espacio de usuario mantiene PTEs obsoletos.\n\nProbado con PoC utilizando emulaci\u00f3n de dispositivo USB dummy_hcd + raw_gadget."}], "lastModified": "2026-07-23T16:10:00.137", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "80C72BB7-F8C5-4503-80AB-CDC8ED7CBECF", "versionEndExcluding": "5.10.258", "versionStartIncluding": "4.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "919C10A9-7951-4A74-BADD-C135A0A8D8B4", "versionEndExcluding": "5.15.209", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "92385813-D91D-480D-83A1-F423D2CBB2BA", "versionEndExcluding": "6.1.175", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A1A92866-F406-43B5-B2D1-CFC274753E9D", "versionEndExcluding": "6.6.140", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5AFBE0EC-CCDF-4207-AE92-ABF958125CA4", "versionEndExcluding": "6.12.88", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BF39AE08-AE6D-4410-8FBE-76F6BF5BF55B", "versionEndExcluding": "6.18.30", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D0893CA7-9AE6-4DFE-AC75-48967D73AD8E", "versionEndExcluding": "7.0.7", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}