CVE-2026-53401 fbdev: omap2: fix use-after-free in omapfb_mmap
A race condition in the Linux kernel's omapfb driver allows local attackers to trigger a use-after-free, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53401?
CVE-2026-53401 is a high-severity use after free vulnerability in Linux kernel, published on 19 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
fbdev: omap2: fix use-after-free in omapfb_mmap
omapfb_mmap() has a race condition with OMAPFB_SETUP_PLANE ioctl that can lead to use-after-free:
The fb_mmap() entry point holds mm_lock but not lock (fb_info->lock), while ioctl handlers like OMAPFB_SETUP_PLANE hold lock but not mm_lock. This allows concurrent execution.
In omapfb_mmap(): 1. rg = omapfb_get_mem_region(ofbi->region); // Get old region ref 2. start = omapfb_get_region_paddr(ofbi); // Read from NEW region 3. len = fix->smem_len; // Read from NEW region 4. vm_iomap_memory(vma, start, len); // Map NEW region memory 5. atomic_inc(&rg->map_count); // Increment OLD region!
Concurrently, OMAPFB_SETUP_PLANE can: - Reassign ofbi->region = new_rg - Update fix->smem_len - OMAPFB_SETUP_MEM then checks NEW region's map_count (0!) and frees it
This leaves userspace with a mapping to freed physical memory.
The fix is to read all required values (start, len) from the same region reference (rg) that will have its map_count incremented, preventing the region from being freed while still mapped.
Weakness: CWE-416
Which versions are affected by CVE-2026-53401?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53401?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-53401 being exploited?
There is no known exploitation of CVE-2026-53401 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53401, DEBIAN-CVE-2026-53401, GHSA-jrv4-9p26-4849, ROOT-OS-DEBIAN-11-CVE-2026-53401, ROOT-OS-DEBIAN-12-CVE-2026-53401, ROOT-OS-DEBIAN-13-CVE-2026-53401 and 2 more.