CVE-2026-97604: Linux kernel · fbdev: vfb: defer cleanup until the last reference
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in de5a0eda59fe4b3eacd1a67c992e54766bb6683f : update Linux kernel when convenient.
Data as of 26 Oct 2026, 12:55 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in de5a0eda59fe4b3eacd1a67c992e54766bb6683f, bf49eac7ed11aabd0b9b790c062742a8e4be97c6, ab664e279eb2a68e55895dd115a9488807280f07 +5
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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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.
References
- git.kernel.org/stable/c/bf49eac7ed11aabd0b9b790c062742a8e4be97c6 (opens in a new tab)
- git.kernel.org/stable/c/040ce3950f64a11e9ee5646c8aaa91fd2e29e245 (opens in a new tab)
- git.kernel.org/stable/c/ab664e279eb2a68e55895dd115a9488807280f07 (opens in a new tab)
- git.kernel.org/stable/c/de5a0eda59fe4b3eacd1a67c992e54766bb6683f (opens in a new tab)
- git.kernel.org/stable/c/86356f13598f59f5acb1754895747dcdaf65a254 (opens in a new tab)
- git.kernel.org/stable/c/5ff1effb047e465cde193d7df95988aa1520035e (opens in a new tab)
- git.kernel.org/stable/c/3c91e51a53cf805e551e5dc8149cd0539a6dbb9d (opens in a new tab)
- git.kernel.org/stable/c/a0a34a40ed299c9c7cff6af163a5b883ee9d6d73 (opens in a new tab)