{"id":"CVE-2026-43497","summary":"fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free","details":"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.","modified":"2026-06-03T03:55:12.171669050Z","published":"2026-05-21T12:12:47.150Z","related":["openSUSE-SU-2026:10859-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43497.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/18dd358de72d57993422cbb5dfb29ccd74efe192"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4f312c30f0368e8d2a76aa650dff73f23490b5e7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5931f5651ee32bd41b3323256b31fcc8e71336ed"},{"type":"WEB","url":"https://git.kernel.org/stable/c/60f711cfd580f86fea8284146ac133804e728f9a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8de779dc40d35d39fa07387b6f921eb11df0f511"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a2c53a3822ee26e8d758071815b9ed3bf6669fc1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/da9b065cedfd3b574f229d5be594e6aa47a27ae6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e3d9865dacd7435b8465848428210d0f0c673311"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43497.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43497"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"7433914efd584b22bb49d3e1eee001f5d0525ecd"},{"fixed":"60f711cfd580f86fea8284146ac133804e728f9a"},{"fixed":"5931f5651ee32bd41b3323256b31fcc8e71336ed"},{"fixed":"e3d9865dacd7435b8465848428210d0f0c673311"},{"fixed":"4f312c30f0368e8d2a76aa650dff73f23490b5e7"},{"fixed":"18dd358de72d57993422cbb5dfb29ccd74efe192"},{"fixed":"da9b065cedfd3b574f229d5be594e6aa47a27ae6"},{"fixed":"a2c53a3822ee26e8d758071815b9ed3bf6669fc1"},{"fixed":"8de779dc40d35d39fa07387b6f921eb11df0f511"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43497.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.19.0"},{"fixed":"5.10.258"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.209"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.140"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.88"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.30"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43497.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H"}]}