CVE-2026-90035

Summary

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

drm/amd/display: fix division by zero in get_estimated_bw()

get_estimated_bw() divides by link->dpia_bw_alloc_config.bw_granularity, which is zeroed by reset_bw_alloc_struct() and only populated once DP_TUNNELING_BW_ALLOC_CAP_CHANGED has been handled.

link_dp_dpia_handle_bw_alloc_status(), the DPCD interrupt handler, calls get_estimated_bw() whenever DP_TUNNELING_ESTIMATED_BW_CHANGED is set, independently of whether DP_TUNNELING_BW_ALLOC_CAP_CHANGED has ever fired for that link. A connected USB4/DPIA tunneling device that reports an estimated-bandwidth change before ever reporting a capability change drives a division by zero in this IRQ path.

link_dpia_send_bw_alloc_request() already guards the same bw_granularity division; add the identical guard here rather than introducing a new pattern.

(cherry picked from commit f2a961457c33dc34223aad5c9e8971de34a4eed3)

Affected Software

VendorProductVersion RangeStatus
LinuxLinux8e5cfe547bf3beeb29d9608be68d22dff2b5012b < 4c5b61b9df6ab33b55f228e1b6579cefad11a9f7affected
LinuxLinux8e5cfe547bf3beeb29d9608be68d22dff2b5012b < ac2ab58a79bf2401ae8c5d1c030bf0a5a376f43aaffected
LinuxLinux8e5cfe547bf3beeb29d9608be68d22dff2b5012b < 4814f28c45f58a71a80d09b80a60da6a063b539aaffected
LinuxLinux8e5cfe547bf3beeb29d9608be68d22dff2b5012b < b08c3d5ee7feadd821208f7c2c1ec02a16ce5878affected
LinuxLinux8e5cfe547bf3beeb29d9608be68d22dff2b5012b < f63de9054da858d57054474c32464106f8375e0daffected
LinuxLinux6.3affected
LinuxLinux0 < 6.3unaffected
LinuxLinux6.6.157 <= 6.6.*unaffected
LinuxLinux6.12.110 <= 6.12.*unaffected
LinuxLinux6.18.51 <= 6.18.*unaffected
LinuxLinux7.2.5 <= 7.2.*unaffected
LinuxLinux7.3-rc2 <= *unaffected

Weaknesses

References