CVE-2025-40293
Published Dec 8, 2025
Modified Apr 15, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: iommufd: Don't overflow during division for dirty tracking If pgshift is 63 then BITS_PER_TYPE(*bitmap->bitmap) * pgsize will overflow to 0 and this triggers divide by 0. In this case the index should just be 0, so reorganize things to divide by shift and avoid hitting any overflows.
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References
Other References
https://git.kernel.org/stable/c/07105e61882ff4a7d58db63cc5f9e90c6c60506c
https://git.kernel.org/stable/c/4c8a4f1d34eced168cc0b3a3dfe7b6dcc2090f69
https://git.kernel.org/stable/c/cb30dfa75d55eced379a42fd67bd5fb7ec38555e
https://git.kernel.org/stable/c/dbf316fc90aa954dcd5440817f4b944627ed63e0
https://git.kernel.org/stable/c/de7f2c67ceb1941b05b04ac35458a03e93cc57b1
Frequently Asked Questions
What is CVE-2025-40293? +
In the Linux kernel, the following vulnerability has been resolved:
iommufd: Don't overflow during division for dirty tracking
If pgshift is 63 then BITS_PER_TYPE(*bitmap->bitmap) * pgsize will overflow
to 0 and this triggers divide by 0.
In this case the index should just be 0, so reorganize things to divide
by shift and avoid hitting any overflows.
How do I check if I'm vulnerable to CVE-2025-40293? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.