CVE-2026-98176
Linux: drm/amdkfd: Avoid integer underflow with ffs in EOP ring size calc
Linux LinuxOperating systemsCVSS
NoneNot scoredExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.16%Chance of exploitation activity in the next 30 days, higher than 5% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 82e1b8299c6da02ce02185c208d2fdf7572b5ea1LinuxCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
Description
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)
Text from CVE List
Affected versions 6
- Linuxaffected: 14328aa58ce523a59996c5a82681c43ec048cc33 before 82e1b8299c6da02ce02185c208d2fdf7572b5ea1CVE List
- Linuxaffected: 14328aa58ce523a59996c5a82681c43ec048cc33 before c883d0a132d430ef7ebb23fd94323be94d0fbdb8CVE List
- Linuxaffected: 5.3CVE List
- Linuxunaffected: all versions before 5.3CVE List
- Linuxunaffected: 7.2.8 through 7.2.*CVE List
- Linuxunaffected: 7.3CVE List