CVE-2025-21724 iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index()
A shift-out-of-bounds error in the Linux kernel's iommufd module can cause undefined behavior and potential denial of service.
- 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-2025-21724?
CVE-2025-21724 is a high-severity vulnerability in Linux kernel, published on 27 Feb 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:
iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index()
Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index() where shifting the constant "1" (of type int) by bitmap->mapped.pgshift (an unsigned long value) could result in undefined behavior.
The constant "1" defaults to a 32-bit "int", and when "pgshift" exceeds 31 (e.g., pgshift = 63) the shift operation overflows, as the result cannot be represented in a 32-bit type.
To resolve this, the constant is updated to "1UL", promoting it to an unsigned long type to match the operand's type.
Weakness: CWE-787
Which versions are affected by CVE-2025-21724?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-21724?
Apply the vendor's patch.
Is CVE-2025-21724 being exploited?
There is no known exploitation of CVE-2025-21724 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-21724, DEBIAN-CVE-2025-21724, GHSA-hx7m-g669-h6j3, ROOT-OS-UBUNTU-2404-CVE-2025-21724, UBUNTU-CVE-2025-21724.