{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89826", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.769Z", "datePublished": "2026-09-16T10:30:58.435Z", "dateUpdated": "2026-10-19T08:53:20.074Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:53:20.074Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/panthor: harden firmware build-info bounds checks\n\npanthor_fw_read_build_info() checks whether the metadata range fits in the\nfirmware image with hdr.meta_start + hdr.meta_size. Both fields are u32, so\nthe addition can wrap and let an out-of-bounds range pass validation.\n\nThe function also reads the \"git_sha: \" prefix without first checking that\nthe metadata is long enough, and meta_size == 0 can underflow the NULL\nterminator index.\n\nUse subtraction-based bounds checking and reject metadata that is too short\nto contain the expected prefix and trailing NULL byte." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The out-of-bounds reads occur only while panthor_fw_load() parses mali_csffw.bin from the local firmware search path at platform probe (panthor_probe→panthor_fw_init→panthor_fw_load_entry→panthor_fw_read_build_info); no network, DRM ioctl, or /dev/dri/renderD* path supplies attacker-controlled build-info headers.\nAC:L - An attacker fully controls the BUILD_INFO_METADATA u32 meta_start and meta_size fields. Setting both to 0, using meta_size shorter than the git_sha prefix, or wrapping meta_start+meta_size deterministically bypasses the old addition check and performs the OOB memcmp, terminator, and %s reads on every load with no race.\nPR:L - panthor_fw_read_build_info() performs no capability or authentication checks on firmware content; on Mali CSF Android, Chromebook, and embedded deployments the GPU firmware image commonly lives on vendor/firmware partitions writable by local non-root system or vendor service accounts, sufficient to plant the crafted blob before driver probe.\nUI:N - After the malicious mali_csffw.bin is in the firmware search path, panthor_fw_read_build_info() runs automatically during driver probe at boot or bind; no separate victim action such as opening a device node or mounting a filesystem is required.\nS:U - The out-of-bounds kernel reads and any resulting oops remain inside the host kernel that loads the Panthor firmware; this is not a VM escape, IOMMU bypass, or other cross-authority breakout.\nC:H - A wrapping or zero meta_size lets drm_info(\"%s\") walk from the git_sha prefix through kernel memory adjacent to the firmware vmalloc buffer until a NUL, and meta_start==0 with meta_size==0 indexes fw->data[0xFFFFFFFF]; these are unbounded out-of-bounds reads, not a few-byte leak.\nI:N - panthor_fw_read_build_info() only memcmp()s, indexes, and prints firmware bytes; the wrapping metadata range is never used as a write destination, so there is no out-of-bounds write, use-after-free, or control-flow hijack primitive.\nA:H - Firmware blobs are vmalloc allocations with guard pages, so the 0xFFFFFFFF terminator index (meta_start=meta_size=0) or an unbounded drm_info %s walk past fw->size readily faults into an unmapped page and oopses or panics the kernel during Mali/Panthor GPU probe." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/gpu/drm/panthor/panthor_fw.c" ], "versions": [ { "version": "2718d91816eeed03c09c8abe872e45f59078768c", "lessThan": "5516f1acfd07564361cf306cc90a8e513df0f096", "status": "affected", "versionType": "git" }, { "version": "2718d91816eeed03c09c8abe872e45f59078768c", "lessThan": "6ae19dce3e8c13ae73590b3f4311abe9f96bbae8", "status": "affected", "versionType": "git" }, { "version": "2718d91816eeed03c09c8abe872e45f59078768c", "lessThan": "8321b093fa6c297b80586460ce6914d9655df170", "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/gpu/drm/panthor/panthor_fw.c" ], "versions": [ { "version": "6.10", "status": "affected" }, { "version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "6.10", "versionEndExcluding": "6.18.51" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/5516f1acfd07564361cf306cc90a8e513df0f096" }, { "url": "https://git.kernel.org/stable/c/6ae19dce3e8c13ae73590b3f4311abe9f96bbae8" }, { "url": "https://git.kernel.org/stable/c/8321b093fa6c297b80586460ce6914d9655df170" } ], "title": "drm/panthor: harden firmware build-info bounds checks", "x_generator": { "engine": "bippy-1.2.0" } } } }