Bug 2383903 (CVE-2025-38482)

Summary: CVE-2025-38482 kernel: comedi: das6402: Fix bit shift out of bounds
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2025-07-28 12:02:16 UTC
In the Linux kernel, the following vulnerability has been resolved:

comedi: das6402: Fix bit shift out of bounds

When checking for a supported IRQ number, the following test is used:

	/* IRQs 2,3,5,6,7, 10,11,15 are valid for "enhanced" mode */
	if ((1 << it->options[1]) & 0x8cec) {

However, `it->options[i]` is an unchecked `int` value from userspace, so
the shift amount could be negative or out of bounds.  Fix the test by
requiring `it->options[1]` to be within bounds before proceeding with
the original test.  Valid `it->options[1]` values that select the IRQ
will be in the range [1,15]. The value 0 explicitly disables the use of
interrupts.

Comment 1 Avinash Hanwate 2025-07-28 15:45:58 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025072814-CVE-2025-38482-f4ed@gregkh/T