{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90069", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.784Z", "datePublished": "2026-09-17T16:05:50.894Z", "dateUpdated": "2026-10-19T08:57:26.441Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:57:26.441Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: acomp - allocate async request context when cloning\n\nACOMP_REQUEST_ON_STACK() reserves only enough storage for the\nsynchronous fallback. When an async implementation is selected, callers\nclone that stack request before retrying, but acomp_request_clone()\ncurrently copies only the stack-sized object. The clone therefore has no\nstorage for the async provider request context, and providers such as QAT\nwrite past the allocation through acomp_request_ctx(). KASAN does report\na slab OOB write.\n\nAllocate a zeroed clone large enough for the runtime acomp request size,\ncopy only the bytes present in the source object, and preserve the\nexisting fallback-on-allocation-failure behavior. Use the runtime reqsize\nbecause an implementation may adjust it during tfm initialization." } ], "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 undersized clone is produced only by ACOMP_REQUEST_CLONE in ubifs_compress_common()/ubifs_decompress_common(), reached from local VFS writeback (write/fsync → ubifs_writepage → do_writepage → ubifs_jnl_write_data → ubifs_compress_folio) or read (ubifs_read_folio → read_block → ubifs_decompress_folio). IPComp uses acomp_request_alloc_extra() and never clones, so no protocol message carries this bug.\nAC:L - When UBIFS's compressor tfm is async, crypto_acomp_compress()/crypto_acomp_decompress() return -EAGAIN for every ACOMP_REQUEST_ON_STACK request, and the following ACOMP_REQUEST_CLONE plus QAT qat_comp_alg_compress_decompress() write through acomp_request_ctx() always overflows the kmemdup; there is no race or uninfluenced layout to win.\nPR:L - An unprivileged user with write permission on a UBIFS inode that inherited UBIFS_COMPR_FL triggers the clone by writing ≥ UBIFS_MIN_COMPR_LEN bytes and fsync(); ubifs_fs_type has no FS_USERNS_MOUNT, but an already-mounted volume needs no capability beyond ordinary file write access.\nUI:N - The attacker creates and writes their own file on the mounted UBIFS volume and forces writeback with fsync() into ubifs_jnl_write_data(); no other user must mount an image or open a file.\nS:U - qat_comp_alg_compress_decompress() writes struct qat_compression_req through acomp_request_ctx() into kernel slab adjacent to the clone; the corruption stays in kernel memory and does not cross a VM, IOMMU, or guest/host boundary.\nC:H - The entire qat_compression_req (firmware request, DMA buffer pointers, qat_compression_ctx * and acomp_req *) is stored past the kmemdup of sizeof(struct acomp_req), so qat_comp_generic_callback() later reads those fields from neighboring slab objects, giving an arbitrary kernel read after heap grooming.\nI:H - qat_comp_alg_compress_decompress() performs a slab out-of-bounds write of sizeof(struct qat_compression_req) via acomp_request_ctx() on the clone, overwriting adjacent heap objects including function pointers and providing a control-flow hijack and arbitrary-write primitive.\nA:H - KASAN reports a slab out-of-bounds write through acomp_request_ctx() on the undersized clone, and overflowing qat_compression_req into the next slab object oopses or panics on the QAT callback or allocator integrity check." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "crypto/acompress.c" ], "versions": [ { "version": "097c432caaa6d91f87732fe991cb08139e31101a", "lessThan": "d48197cbd5d3476c7deea644972e9ec510865ec2", "status": "affected", "versionType": "git" }, { "version": "097c432caaa6d91f87732fe991cb08139e31101a", "lessThan": "889fa17a0af09ff93a9166abc82ee7a654faa49b", "status": "affected", "versionType": "git" }, { "version": "097c432caaa6d91f87732fe991cb08139e31101a", "lessThan": "ee440d4fc0d2f15894ab1f64c474a3adbc858880", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "crypto/acompress.c" ], "versions": [ { "version": "6.16", "status": "affected" }, { "version": "0", "lessThan": "6.16", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "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": "6.16", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d48197cbd5d3476c7deea644972e9ec510865ec2" }, { "url": "https://git.kernel.org/stable/c/889fa17a0af09ff93a9166abc82ee7a654faa49b" }, { "url": "https://git.kernel.org/stable/c/ee440d4fc0d2f15894ab1f64c474a3adbc858880" } ], "title": "crypto: acomp - allocate async request context when cloning", "x_generator": { "engine": "bippy-1.2.0" } } } }