fbdev: vfb: defer cleanup until the last reference
Summary
| CVE | CVE-2026-97604 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 11:17:14 UTC |
| Updated | 2026-10-19 10:17:30 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: fbdev: vfb: defer cleanup until the last reference FBIOGETCMAP takes a shallow snapshot of info->cmap and performs the usercopy after dropping info->lock. vfb_remove() frees the colormap immediately after unregistering the framebuffer, even when an open file still holds a reference to fb_info. A concurrent driver unbind can therefore free the colormap while the ioctl copies it to userspace. KASAN reports: BUG: KASAN: slab-use-after-free in _copy_to_user Read of size 512 by task poc/125 _copy_to_user (./include/linux/instrumented.h:129 ./include/linux/uaccess.h:201 lib/usercopy.c:24) fb_cmap_to_user (./include/linux/uaccess.h:230 drivers/video/fbdev/core/fbcmap.c:211) do_fb_ioctl (drivers/video/fbdev/core/fb_chrdev.c:114) Allocated by task 1: fb_alloc_cmap_gfp (./include/linux/slab.h:973 ./include/linux/slab.h:1290 drivers/video/fbdev/core/fbcmap.c:108) vfb_probe (drivers/video/fbdev/vfb.c:459) Freed by task 124: fb_dealloc_cmap (drivers/video/fbdev/core/fbcmap.c:151) vfb_remove (drivers/video/fbdev/vfb.c:489) unregister_framebuffer() drops the registration reference, and fbdev calls fb_destroy after the last put_fb_info(). Move the registered framebuffer's cleanup into an fb_destroy callback so its colormap and screen buffer stay alive until all file references have been released. |
Risk And Classification
EPSS: 0.002100000 probability, percentile 0.102540000 (date 2026-10-05)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 5e266e2e0e19532c1b8e2e2bff1eb6ccf42e478a bf49eac7ed11aabd0b9b790c062742a8e4be97c6 git | Not specified |
| CNA | Linux | Linux | affected 5e266e2e0e19532c1b8e2e2bff1eb6ccf42e478a 040ce3950f64a11e9ee5646c8aaa91fd2e29e245 git | Not specified |
| CNA | Linux | Linux | affected 5e266e2e0e19532c1b8e2e2bff1eb6ccf42e478a ab664e279eb2a68e55895dd115a9488807280f07 git | Not specified |
| CNA | Linux | Linux | affected 5e266e2e0e19532c1b8e2e2bff1eb6ccf42e478a de5a0eda59fe4b3eacd1a67c992e54766bb6683f git | Not specified |
| CNA | Linux | Linux | affected 5e266e2e0e19532c1b8e2e2bff1eb6ccf42e478a 86356f13598f59f5acb1754895747dcdaf65a254 git | Not specified |
| CNA | Linux | Linux | affected 5e266e2e0e19532c1b8e2e2bff1eb6ccf42e478a 5ff1effb047e465cde193d7df95988aa1520035e git | Not specified |
| CNA | Linux | Linux | affected 5e266e2e0e19532c1b8e2e2bff1eb6ccf42e478a 3c91e51a53cf805e551e5dc8149cd0539a6dbb9d git | Not specified |
| CNA | Linux | Linux | affected 5e266e2e0e19532c1b8e2e2bff1eb6ccf42e478a a0a34a40ed299c9c7cff6af163a5b883ee9d6d73 git | Not specified |
| CNA | Linux | Linux | affected 2.6.30 | Not specified |
| CNA | Linux | Linux | unaffected 2.6.30 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.271 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.222 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.189 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.158 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.111 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.53 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.7 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/5ff1effb047e465cde193d7df95988aa1520035e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/bf49eac7ed11aabd0b9b790c062742a8e4be97c6 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/3c91e51a53cf805e551e5dc8149cd0539a6dbb9d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/86356f13598f59f5acb1754895747dcdaf65a254 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ab664e279eb2a68e55895dd115a9488807280f07 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/de5a0eda59fe4b3eacd1a67c992e54766bb6683f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a0a34a40ed299c9c7cff6af163a5b883ee9d6d73 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/040ce3950f64a11e9ee5646c8aaa91fd2e29e245 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.