CVE-2023-53800 ubi: Fix use-after-free when volume resizing failed
A use-after-free vulnerability in the Linux kernel UBI driver allows local attackers to potentially execute arbitrary code or escalate privileges via volume resizing operations.
- 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-2023-53800?
CVE-2023-53800 is a high-severity use after free vulnerability in Linux, published on 9 Dec 2025. 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:
ubi: Fix use-after-free when volume resizing failed
There is an use-after-free problem reported by KASAN: ================================================================== BUG: KASAN: use-after-free in ubi_eba_copy_table+0x11f/0x1c0 [ubi] Read of size 8 at addr ffff888101eec008 by task ubirsvol/4735
CPU: 2 PID: 4735 Comm: ubirsvol Not tainted 6.1.0-rc1-00003-g84fa3304a7fc-dirty #14 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x44 print_report+0x171/0x472 kasan_report+0xad/0x130 ubi_eba_copy_table+0x11f/0x1c0 [ubi] ubi_resize_volume+0x4f9/0xbc0 [ubi] ubi_cdev_ioctl+0x701/0x1850 [ubi] __x64_sys_ioctl+0x11d/0x170 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK>
When ubi_change_vtbl_record() returns an error in ubi_resize_volume(), "new_eba_tbl" will be freed on error handing path, but it is holded by "vol->eba_tbl" in ubi_eba_replace_table(). It means that the liftcycle of "vol->eba_tbl" and "vol" are different, so when resizing volume in next time, it causing an use-after-free fault.
Fix it by not freeing "new_eba_tbl" after it replaced in ubi_eba_replace_table(), while will be freed in next volume resizing.
Which versions are affected by CVE-2023-53800?
How do I fix CVE-2023-53800?
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-2023-53800 being exploited?
There is no known exploitation of CVE-2023-53800 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-53800, DEBIAN-CVE-2023-53800, GHSA-7jjf-hg6r-x4hg, UBUNTU-CVE-2023-53800.