{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-90069", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-90069" ], "published": "2026-09-17T16:10:40Z", "summary": "crypto: acomp - allocate async request context when cloning", "details": "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.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:13", "name": "linux" }, "versions": [ "1:6.18.29-1+rpt1", "1:6.18.33-1+rpt1", "1:6.18.34-1+rpt1", "1:6.18.39-1+rpt1", "1:6.18.50-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.18.29+rpt-rpi-2712", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v6", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v7", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-2712", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v6", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v7", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-2712", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v6", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v7", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-2712", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v6", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v7", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8-rt", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-2712", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v6", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v7", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8-rt", "binary_version": "1:6.18.50-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.18.29-1+rpt1": { "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc", "upstream_version": "6.18.29", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.33-1+rpt1": { "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412", "upstream_version": "6.18.33", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.34-1+rpt1": { "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af", "upstream_version": "6.18.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.39-1+rpt1": { "linux_commit": "60ea684a8ace97bb0db1a16e20753bdd6ab371ff", "upstream_version": "6.18.39", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" }, "1:6.18.50-1+rpt1": { "linux_commit": "cff533aec2fa601846766b32ff57204e0a61bed7", "upstream_version": "6.18.50", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.52" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-90069" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/d48197cbd5d3476c7deea644972e9ec510865ec2" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/889fa17a0af09ff93a9166abc82ee7a654faa49b" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/ee440d4fc0d2f15894ab1f64c474a3adbc858880" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-09-18T17:55:42Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "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 \u2192 ubifs_writepage \u2192 do_writepage \u2192 ubifs_jnl_write_data \u2192 ubifs_compress_folio) or read (ubifs_read_folio \u2192 read_block \u2192 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 \u2265 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." } } }