{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89882","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.772Z","datePublished":"2026-09-16T10:31:47.644Z","dateUpdated":"2026-09-16T14:39:33.170Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-16T14:39:33.170Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: rkvdec: hevc: guard INTER_REF_PIC_SET_PRED index underflow\n\nst_ref_pic_set_prediction() computes the reference RPS index as\nst_rps_idx - (delta_idx_minus1 + 1) per HEVC spec equation 7-59.\nBoth operands are u8, so when delta_idx_minus1 + 1 exceeds the\ncurrent index the subtraction wraps and the subsequent array access\nat calculated_rps_st_sets[ref_rps_idx] reads far out of bounds.\n\nA userspace V4L2 client that can open the RKVDEC m2m decoder can\nsubmit an EXT_SPS_ST_RPS control with INTER_REF_PIC_SET_PRED set\nand delta_idx_minus1 crafted to trigger the underflow.\n\nReject the entry early when the reference index would underflow."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The EXT_SPS_ST_RPS control is applied only via VIDIOC_S_EXT_CTRLS or a media request on the local rkvdec V4L2 m2m node (/dev/videoN), then consumed in rkvdec_hevc_run after QBUF/STREAMON. The HEVC RPS parser is not reachable from the network stack.\nAC:L - The attacker sets INTER_REF_PIC_SET_PRED and a delta_idx_minus1 that makes the u8 index wrap (e.g. idx=0 and delta_idx_minus1=0 yields ref_rps_idx=255). v4l2-ctrls never validates delta_idx_minus1 and try_ctrl only checks SPS, so the out-of-bounds access is deterministic with no race.\nPR:L - rkvdec_open and the ioctl path perform no capability check. An unprivileged local account that can open the decoder node is sufficient, typically via the video group or the Android/embedded media codec service that sandboxed apps can reach.\nUI:N - The attacking process itself opens the decoder, attaches a crafted EXT_SPS_ST_RPS control, queues buffers, and starts streaming. No separate victim action is required.\nS:U - The underflow corrupts kernel heap, stack, and the driver's DMA RPS table inside the same kernel security authority. This is local privilege escalation, not a VM escape, IOMMU bypass, or sandbox-boundary crossing.\nC:H - A wrapped u8 ref_rps_idx indexes calculated_rps_st_sets tens of kilobytes past the kzalloc allocation (up to 255 * sizeof(struct calculated_rps_st_set)). Those out-of-bounds bytes become loop bounds and are copied into the hardware RPS table, giving an attacker-steerable kernel memory read.\nI:H - Out-of-bounds num_delta_pocs overflows the 16-byte stack arrays use_delta_flag and used_by_curr_pic_flag, later loops write past st_rps->delta_poc_s0[16] on the heap, and assemble_hw_st_rps bit-writes rps->info with an unbounded index. That is an attacker-influenced kernel write usable for control-flow hijack.\nA:H - The far out-of-bounds pointer, stack smash, and DMA RPS-table overrun each cause a kernel oops, KASAN report, or wedged decoder, and the attacker can repeat the sequence at will."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c"],"versions":[{"version":"c9a59dc2acc72789d5c778af080d1e65af84862c","lessThan":"74938f83a8abbee8f502dfb5d94213b2497d1edf","status":"affected","versionType":"git"},{"version":"c9a59dc2acc72789d5c778af080d1e65af84862c","lessThan":"052c5ed5a1d96a6b24fd50ccda16fc6841ee7ca3","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/media/platform/rockchip/rkvdec/rkvdec-hevc-common.c"],"versions":[{"version":"7.0","status":"affected"},{"version":"0","lessThan":"7.0","status":"unaffected","versionType":"semver"},{"version":"7.2.5","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.3-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/74938f83a8abbee8f502dfb5d94213b2497d1edf"},{"url":"https://git.kernel.org/stable/c/052c5ed5a1d96a6b24fd50ccda16fc6841ee7ca3"}],"title":"media: rkvdec: hevc: guard INTER_REF_PIC_SET_PRED index underflow","x_generator":{"engine":"bippy-1.2.0"}}}}