CVE-2025-38214
What it is
In the Linux kernel, the following vulnerability has been resolved: fbdev: Fix fb_set_var to prevent null-ptr-deref in fb_videomode_to_var If fb_add_videomode() in fb_set_var() fails to allocate memory for fb_videomode, later it may lead to a null-ptr dereference in fb_videomode_to_var(), as the fb_info is registered while not having the mode in modelist that is expected to be there, i.e. the one that is described in fb_info->var. ================================================================ general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 30371 Comm: syz-executor.1 Not tainted 5.10.226-syzkaller #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:fb_videomode_to_var+0x24/0x610 drivers/video/fbdev/core/modedb.c:901 Call Trace: display_to_var+0x3a/0x7c0 drivers/video/fbdev/core/fbcon.c:929 fbcon_resize+0x3e2/0x8f0 drivers/video/fbdev/core/fbcon.c:2071 resize_screen drivers/tty/vt/vt.c:1176 [inline] vc_do_resize+0x53a/0x1170 drivers/tty/vt/vt.c:1263 fbcon_modechanged+0x3ac/0x6e0 drivers/video/fbdev/core/fbcon.c:2720 fbcon_update_vcs+0x43/0x60 drivers/video/fbdev/core/fbcon.c:2776 do_fb_ioctl+0x6d2/0x740 drivers/video/fbdev/core/fbmem.c:1128 fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1203 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 ================================================================ The reason is that fb_info->var is being modified in fb_set_var(), and then fb_videomode_to_var() is called. If it fails to add the mode to fb_info->modelist, fb_set_var() returns error, but does not restore the old value of fb_info->var. Restore fb_info->var on failure the same way it is done earlier in the function. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-476 · NULL pointer dereference
- Record status
- Modified
Affected
- Linux Kernel < 5.4.295
- Linux Kernel < 5.10.239
- Linux Kernel < 5.15.186
- Linux Kernel < 6.1.142
- Linux Kernel < 6.6.95
- Linux Kernel < 6.12.35
- Linux Kernel < 6.15.4
- Linux Kernel 2.6.12
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-38214.md and follow it. Check whether this project is affected by CVE-2025-38214. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/05f6e183879d9785a3cdf2f08a498bc31b7a20aa
- https://git.kernel.org/stable/c/1a10d91766eb6ddfd5414e4785611e33a4fe0f9b
- https://git.kernel.org/stable/c/3ca78032a388a0795201792b36e6fc9b6e6e8eed
- https://git.kernel.org/stable/c/8a3a2887794b2c8e78b3e5d6e3de724527c9f41b
- https://git.kernel.org/stable/c/b3071bb463ea1e6c686d0dc9638fc940f2f5cf17
- https://git.kernel.org/stable/c/ee20216f12d9482cd70e44dae5e7fabb38367c71
- https://git.kernel.org/stable/c/fab201d72fde38d081e2c5d4ad25595c535b7b22
- https://git.kernel.org/stable/c/ff0e037241173b574b385bff53d67567b9816db5
References
- https://git.kernel.org/stable/c/05f6e183879d9785a3cdf2f08a498bc31b7a20aa
- https://git.kernel.org/stable/c/1a10d91766eb6ddfd5414e4785611e33a4fe0f9b
- https://git.kernel.org/stable/c/3ca78032a388a0795201792b36e6fc9b6e6e8eed
- https://git.kernel.org/stable/c/8a3a2887794b2c8e78b3e5d6e3de724527c9f41b
- https://git.kernel.org/stable/c/b3071bb463ea1e6c686d0dc9638fc940f2f5cf17
- https://git.kernel.org/stable/c/ee20216f12d9482cd70e44dae5e7fabb38367c71
- https://git.kernel.org/stable/c/fab201d72fde38d081e2c5d4ad25595c535b7b22
- https://git.kernel.org/stable/c/ff0e037241173b574b385bff53d67567b9816db5
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html