CVE-2023-53468 ubifs: Fix memory leak in alloc_wbufs()
A memory leak in the Linux kernel's UBIFS filesystem allows attackers to cause a denial of service by exhausting system memory during mount 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-2023-53468?
CVE-2023-53468 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 Oct 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:
ubifs: Fix memory leak in alloc_wbufs()
kmemleak reported a sequence of memory leaks, and show them as following:
unreferenced object 0xffff8881575f8400 (size 1024): comm "mount", pid 19625, jiffies 4297119604 (age 20.383s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8176cecd>] __kmalloc+0x4d/0x150 [<ffffffffa0406b2b>] ubifs_mount+0x307b/0x7170 [ubifs] [<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0 [<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230 [<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0 [<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270 [<ffffffff83c14295>] do_syscall_64+0x35/0x80 [<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
unreferenced object 0xffff8881798a6e00 (size 512): comm "mount", pid 19677, jiffies 4297121912 (age 37.816s) hex dump (first 32 bytes): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk backtrace: [<ffffffff8176cecd>] __kmalloc+0x4d/0x150 [<ffffffffa0418342>] ubifs_wbuf_init+0x52/0x480 [ubifs] [<ffffffffa0406ca5>] ubifs_mount+0x31f5/0x7170 [ubifs] [<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0 [<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230 [<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0 [<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270 [<ffffffff83c14295>] do_syscall_64+0x35/0x80 [<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
The problem is that the ubifs_wbuf_init() returns an error in the loop which in the alloc_wbufs(), then the wbuf->buf and wbuf->inodes that were successfully alloced before are not freed.
Fix it by adding error hanging path in alloc_wbufs() which frees the memory alloced before when ubifs_wbuf_init() returns an error.
Weakness: CWE-401
Which versions are affected by CVE-2023-53468?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53468?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-53468 being exploited?
There is no known exploitation of CVE-2023-53468 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53468, DEBIAN-CVE-2023-53468, GHSA-rwqr-mq87-5p2c, UBUNTU-CVE-2023-53468.