CVE-2023-54020 dmaengine: sf-pdma: pdma_desc memory leak fix
A memory leak in the Linux kernel sf-pdma driver allows attackers to cause memory starvation and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54020?
CVE-2023-54020 is a denial of service vulnerability in Linux, published on 24 Dec 2025.
Official description
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: sf-pdma: pdma_desc memory leak fix
Commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a DMA channel") changed sf_pdma_prep_dma_memcpy() to unconditionally allocate a new sf_pdma_desc each time it is called.
The driver previously recycled descs, by checking the in_use flag, only allocating additional descs if the existing one was in use. This logic was removed in commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a DMA channel"), but sf_pdma_free_desc() was not changed to handle the new behaviour.
As a result, each time sf_pdma_prep_dma_memcpy() is called, the previous descriptor is leaked, over time leading to memory starvation:
unreferenced object 0xffffffe008447300 (size 192): comm "irq/39-mchp_dsc", pid 343, jiffies 4294906910 (age 981.200s) hex dump (first 32 bytes): 00 00 00 ff 00 00 00 00 b8 c1 00 00 00 00 00 00 ................ 00 00 70 08 10 00 00 00 00 00 00 c0 00 00 00 00 ..p............. backtrace: [<00000000064a04f4>] kmemleak_alloc+0x1e/0x28 [<00000000018927a7>] kmem_cache_alloc+0x11e/0x178 [<000000002aea8d16>] sf_pdma_prep_dma_memcpy+0x40/0x112
Add the missing kfree() to sf_pdma_free_desc(), and remove the redundant in_use flag.
Which versions are affected by CVE-2023-54020?
How do I fix CVE-2023-54020?
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-2023-54020 being exploited?
There is no known exploitation of CVE-2023-54020 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54020, DEBIAN-CVE-2023-54020, GHSA-4cm4-vw36-jc7r, ROOT-OS-DEBIAN-11-CVE-2023-54020, UBUNTU-CVE-2023-54020.