CVE-2026-98176

Summary

In the Linux kernel, the following vulnerability has been resolved:

drm/amdkfd: Avoid integer underflow with ffs in EOP ring size calc

The low 6 bits of cp_hqd_eop_control store the base-2 logarithm of the EOP ring size. This was calculated as

ffs(q->eop_ring_buffer_size / sizeof(unsigned int)) - 1 - 1

But ffs can in theory return 1 or 0, so this could underflow (although in practice the ring buffer size cannot be less than 4096).

Change this to

ffs(q->eop_ring_buffer_size / sizeof(unsigned int) / 4)

using properties of logarithms.

(cherry picked from commit 4f18c56630383c14bfc6b2d65f88f2f895d2121a)

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 82e1b8299c6da02ce02185c208d2fdf7572b5ea1affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c883d0a132d430ef7ebb23fd94323be94d0fbdb8affected
LinuxLinux0 < 7.2.8affected
LinuxLinux7.2.8 <= 7.2.*unaffected
LinuxLinux7.3-rc4 <= *unaffected

Weaknesses

References