CVE-2026-89818

Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn: fix integer overflow in dec_msg buffer count check If the supplied msg[2] (num_buffers) is 0x3FFFFFFF, the expression 6 + num_buffers * 4 wraps to 2 and the bounds check passes, letting the parser loop far past the end of the message BO. Triggering it additionally requires a ~4GiB mapping so that msg[1] survives the earlier "header does not fit in BO" check. Rewrite the test in division form, which is overflow-free by construction. Also update the message to reflect that msg is invalid.

References

• https://git.kernel.org/stable/c/47799e1f893d47d8af231710a61065e3ec8a13e8
• https://git.kernel.org/stable/c/4d7390530853eb7befda9cc786e4c86e8ad7ac9e
• https://git.kernel.org/stable/c/6dceaeceaa7c8396339f3ea34b0110cb912ca61b
• https://git.kernel.org/stable/c/7e28853c78c20bb8ba4c1dba702430cd05e09f76
• https://git.kernel.org/stable/c/9ae19bd60891bea0a7b7504cc8dbfe74570ac3b3