{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-80631", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.776Z", "datePublished": "2026-08-28T06:48:47.166Z", "dateUpdated": "2026-08-29T06:21:31.506Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-29T06:21:31.506Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: lzo: reject compressed segment that overflows the compressed input\n\nlzo_decompress_bio() validates each on-disk segment length seg_len only\nagainst the workspace cbuf size, not against the compressed input size\n(compressed_len, the total folio bytes of the bio). A crafted extent can\ncarry a segment whose seg_len passes the cbuf check but runs past the end\nof the bio, so copy_compressed_segment() walks off the last folio:\nget_current_folio() then returns the NULL folio from bio_next_folio(), and\nwith CONFIG_BTRFS_ASSERT disabled (default) folio_size(NULL) faults.\n\n BUG: KASAN: null-ptr-deref in lzo_decompress_bio (fs/btrfs/lzo.c:383)\n Read of size 8 at addr 0000000000000000 by task kworker/u8:1/29\n Workqueue: btrfs-endio simple_end_io_work\n kasan_report (mm/kasan/report.c:590)\n lzo_decompress_bio (fs/btrfs/lzo.c:383)\n end_bbio_compressed_read (fs/btrfs/compression.c:1065)\n btrfs_bio_end_io (fs/btrfs/bio.c:135)\n btrfs_check_read_bio (fs/btrfs/bio.c:180 fs/btrfs/bio.c:285)\n simple_end_io_work\n process_one_work\n worker_thread\n\nReject any segment whose payload would extend beyond compressed_len before\ncopying it, treating it as corruption like the other on-disk validation\nfailures in this function."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - On btrfs-backed NAS/cloud storage exported via nfsd or ksmbd, a remote client's read I/O is served by the server kernel through btrfs_do_readpage\u2192btrfs_submit_compressed_read\u2192lzo_decompress_bio, reaching the vulnerable LZO segment parser without local syscall access on the server.\nAC:L - A crafted on-disk LZO segment header with seg_len that passes the cbuf-size check but exceeds remaining compressed_len deterministically drives copy_compressed_segment past the last bio folio; no race, special memory layout, or rare kernel config is required.\nPR:N - Triggering needs only read access to btrfs content on an already-mounted/exported volume (e.g., NFS/ksmbd read); planting malformed LZO segment metadata is done via offline btrfs image crafting and does not require init-namespace root or a local account on the victim.\nUI:N - Exploitation is the attacker's own read against a btrfs volume that already contains the crafted LZO-compressed extent (backup restore, shared storage, or export); no separate victim mount, click, or plug-in action is needed beyond that read.\nS:U - Impact is a kernel NULL-pointer dereference and oops in the btrfs-endio workqueue on the host parsing attacker-supplied compressed data; this is standard host-kernel failure within one security authority, not VM escape or IOMMU bypass.\nC:N - The demonstrated failure is a null-ptr-deref read at address 0 in folio_size(NULL) when walking past the bio; unlike slab OOB reads in related btrfs LZO bugs, no adjacent kernel memory is disclosed before the fault.\nI:N - The bug faults during folio iteration before completing an out-of-bounds copy or decompression; there is no demonstrated or plausible kernel heap/stack write, control-flow hijack, or other integrity corruption beyond attacker-controlled on-disk bytes already in the bio.\nA:H - The NULL dereference in lzo_decompress_bio runs in btrfs-endio kworker context and produces a KASAN-reported kernel oops/panic; any process read (local or remote via NFS/ksmbd) of the crafted extent can repeatedly crash the host."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/btrfs/lzo.c"], "versions": [{"version": "a6e66e6f8c1b685e11b778bef614480a9c1a5278", "lessThan": "1641d058adfbd50cf95d54581ed5d142ee82c07f", "status": "affected", "versionType": "git"}, {"version": "a6e66e6f8c1b685e11b778bef614480a9c1a5278", "lessThan": "b0d27d43791b7a3057c3c4aedf9b4aa033d37c46", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/btrfs/lzo.c"], "versions": [{"version": "5.15", "status": "affected"}, {"version": "0", "lessThan": "5.15", "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": "5.15", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1641d058adfbd50cf95d54581ed5d142ee82c07f"}, {"url": "https://git.kernel.org/stable/c/b0d27d43791b7a3057c3c4aedf9b4aa033d37c46"}], "title": "btrfs: lzo: reject compressed segment that overflows the compressed input", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/btrfs/lzo.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "1641d058adfbd50cf95d54581ed5d142ee82c07f", "status": "affected", "version": "a6e66e6f8c1b685e11b778bef614480a9c1a5278", "versionType": "git"}, {"lessThan": "b0d27d43791b7a3057c3c4aedf9b4aa033d37c46", "status": "affected", "version": "a6e66e6f8c1b685e11b778bef614480a9c1a5278", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/btrfs/lzo.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.15"}, {"lessThan": "5.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: lzo: reject compressed segment that overflows the compressed input\n\nlzo_decompress_bio() validates each on-disk segment length seg_len only\nagainst the workspace cbuf size, not against the compressed input size\n(compressed_len, the total folio bytes of the bio). A crafted extent can\ncarry a segment whose seg_len passes the cbuf check but runs past the end\nof the bio, so copy_compressed_segment() walks off the last folio:\nget_current_folio() then returns the NULL folio from bio_next_folio(), and\nwith CONFIG_BTRFS_ASSERT disabled (default) folio_size(NULL) faults.\n\n BUG: KASAN: null-ptr-deref in lzo_decompress_bio (fs/btrfs/lzo.c:383)\n Read of size 8 at addr 0000000000000000 by task kworker/u8:1/29\n Workqueue: btrfs-endio simple_end_io_work\n kasan_report (mm/kasan/report.c:590)\n lzo_decompress_bio (fs/btrfs/lzo.c:383)\n end_bbio_compressed_read (fs/btrfs/compression.c:1065)\n btrfs_bio_end_io (fs/btrfs/bio.c:135)\n btrfs_check_read_bio (fs/btrfs/bio.c:180 fs/btrfs/bio.c:285)\n simple_end_io_work\n process_one_work\n worker_thread\n\nReject any segment whose payload would extend beyond compressed_len before\ncopying it, treating it as corruption like the other on-disk validation\nfailures in this function."}], "id": "CVE-2026-80631", "lastModified": "2026-08-29T07:16:47.210", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-28T08:16:48.010", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1641d058adfbd50cf95d54581ed5d142ee82c07f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b0d27d43791b7a3057c3c4aedf9b4aa033d37c46"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: btrfs: lzo: reject compressed segment that overflows the compressed input", "id": "2525408", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2525408"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nbtrfs: lzo: reject compressed segment that overflows the compressed input\nlzo_decompress_bio() validates each on-disk segment length seg_len only\nagainst the workspace cbuf size, not against the compressed input size\n(compressed_len, the total folio bytes of the bio). A crafted extent can\ncarry a segment whose seg_len passes the cbuf check but runs past the end\nof the bio, so copy_compressed_segment() walks off the last folio:\nget_current_folio() then returns the NULL folio from bio_next_folio(), and\nwith CONFIG_BTRFS_ASSERT disabled (default) folio_size(NULL) faults.\nBUG: KASAN: null-ptr-deref in lzo_decompress_bio (fs/btrfs/lzo.c:383)\nRead of size 8 at addr 0000000000000000 by task kworker/u8:1/29\nWorkqueue: btrfs-endio simple_end_io_work\nkasan_report (mm/kasan/report.c:590)\nlzo_decompress_bio (fs/btrfs/lzo.c:383)\nend_bbio_compressed_read (fs/btrfs/compression.c:1065)\nbtrfs_bio_end_io (fs/btrfs/bio.c:135)\nbtrfs_check_read_bio (fs/btrfs/bio.c:180 fs/btrfs/bio.c:285)\nsimple_end_io_work\nprocess_one_work\nworker_thread\nReject any segment whose payload would extend beyond compressed_len before\ncopying it, treating it as corruption like the other on-disk validation\nfailures in this function.", "A flaw was found in the Linux kernel's Btrfs filesystem, specifically within its LZO decompression functionality. A local attacker could provide a specially crafted Btrfs image containing a compressed segment that, due to improper validation of its length, overflows the compressed input buffer. This out-of-bounds read leads to a null-pointer dereference, which can cause a system crash, resulting in a Denial of Service (DoS)."], "name": "CVE-2026-80631", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-28T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-80631\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-80631\nhttps://lore.kernel.org/linux-cve-announce/2026082838-CVE-2026-80631-96c3@gregkh/T"], "threat_severity": "Moderate"}