{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80876", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.799Z", "datePublished": "2026-09-04T16:48:50.082Z", "dateUpdated": "2026-09-04T16:48:50.082Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-04T16:48:50.082Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Fix event length with forced 8-byte alignment\n\nWhen RB_FORCE_8BYTE_ALIGNMENT is true, rb_calculate_event_length()\nreserves the space of event->array[0] for placing the data length and\nrb_update_event() stores the data length in event->array[0]\naccordingly. As a result the whole event length will add extra 4 bytes\nfor sizeof(event.array[0]) unconditionally.\n\nBut ring_buffer_event_length() only subtracts the\nsizeof(event->array[0]) for events larger than RB_MAX_SMALL_DATA +\nsizeof(event->array[0]). As a result, small events on architectures\nwith RB_FORCE_8BYTE_ALIGNMENT=true report a data length that is 4\nbytes larger than expected.\n\nTo fix it, add the RB_FORCE_8BYTE_ALIGNMENT as a condition to subtract\nthe size of that length field whenever RB_FORCE_8BYTE_ALIGNMENT is\ntrue.\n\nThis issue is observed in a riscv64 kernel with\nCONFIG_HAVE_64BIT_ALIGNED_ACCESS set to y, when we run ftrace selftest\ntrace_marker_raw.tc, we get the weird log: for cases where the id is\n1..100, the number of data field is 8*N, but once id exceeds 100, the\nnumber of data field becomes 8*N+4:\n # 1 buf: 58 00 00 00 80 5e d1 63 (number of data field is 8*1)\n ...\n # a buf: 58 ... (number of data field is 8*2)\n ...\n # 64 buf: 58 ... (number of data field is 8*13)\n # 65 buf: 58 ... (number of data field is 8*13+4)\n\nAfter applying this change, the number of data field keeps being 8*N+4\nconsistently." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/trace/ring_buffer.c" ], "versions": [ { "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05", "lessThan": "7c9f0ccf9f04142458d2ac3d39414f4acae242f0", "status": "affected", "versionType": "git" }, { "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05", "lessThan": "24c3fa71f9947b0e1f3b954db1b769b44140192e", "status": "affected", "versionType": "git" }, { "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05", "lessThan": "14057268e79654c3e8ea2c9b5204cb9644b2964d", "status": "affected", "versionType": "git" }, { "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05", "lessThan": "dbcb8635b1eb7603818591cf745c7b1d714f7ac6", "status": "affected", "versionType": "git" }, { "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05", "lessThan": "cfada73fabe2ccc06ec77fe2ceaa088689213326", "status": "affected", "versionType": "git" }, { "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05", "lessThan": "ec5e96aee75d27779b9a860307679f13f33adb0c", "status": "affected", "versionType": "git" }, { "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05", "lessThan": "3a63a11897c7ba32d1be7a3fdbc48a8b01cf4992", "status": "affected", "versionType": "git" }, { "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05", "lessThan": "c37e0a4b79a6bbb96ce5ffe279d7c001e20529e0", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/trace/ring_buffer.c" ], "versions": [ { "version": "2.6.34", "status": "affected" }, { "version": "0", "lessThan": "2.6.34", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "2.6.34", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7c9f0ccf9f04142458d2ac3d39414f4acae242f0" }, { "url": "https://git.kernel.org/stable/c/24c3fa71f9947b0e1f3b954db1b769b44140192e" }, { "url": "https://git.kernel.org/stable/c/14057268e79654c3e8ea2c9b5204cb9644b2964d" }, { "url": "https://git.kernel.org/stable/c/dbcb8635b1eb7603818591cf745c7b1d714f7ac6" }, { "url": "https://git.kernel.org/stable/c/cfada73fabe2ccc06ec77fe2ceaa088689213326" }, { "url": "https://git.kernel.org/stable/c/ec5e96aee75d27779b9a860307679f13f33adb0c" }, { "url": "https://git.kernel.org/stable/c/3a63a11897c7ba32d1be7a3fdbc48a8b01cf4992" }, { "url": "https://git.kernel.org/stable/c/c37e0a4b79a6bbb96ce5ffe279d7c001e20529e0" } ], "title": "ring-buffer: Fix event length with forced 8-byte alignment", "x_generator": { "engine": "bippy-1.2.0" } } } }