CVE-2026-89882

Summary

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

media: rkvdec: hevc: guard INTER_REF_PIC_SET_PRED index underflow

st_ref_pic_set_prediction() computes the reference RPS index as st_rps_idx - (delta_idx_minus1 + 1) per HEVC spec equation 7-59. Both operands are u8, so when delta_idx_minus1 + 1 exceeds the current index the subtraction wraps and the subsequent array access at calculated_rps_st_sets[ref_rps_idx] reads far out of bounds.

A userspace V4L2 client that can open the RKVDEC m2m decoder can submit an EXT_SPS_ST_RPS control with INTER_REF_PIC_SET_PRED set and delta_idx_minus1 crafted to trigger the underflow.

Reject the entry early when the reference index would underflow.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxc9a59dc2acc72789d5c778af080d1e65af84862c < 74938f83a8abbee8f502dfb5d94213b2497d1edfaffected
LinuxLinuxc9a59dc2acc72789d5c778af080d1e65af84862c < 052c5ed5a1d96a6b24fd50ccda16fc6841ee7ca3affected
LinuxLinux7.0affected
LinuxLinux0 < 7.0unaffected
LinuxLinux7.2.5 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References