{"schema":"threatline.record/2","record":{"id":"CVE-2026-98127","aliases":[],"summary":"smb/client: validate new EOF for insert range","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb/client: validate new EOF for insert range\n\nsmb3_insert_range() does not check if the new file size\n(i_size + len) is valid. This allows FALLOC_FL_INSERT_RANGE to bypass\nRLIMIT_FSIZE, exceed s_maxbytes, or produce a size outside the loff_t\nrange.\n\nUse check_add_overflow() to calculate the new EOF. Validate it with\ninode_newsize_ok() before modifying the file.\n\nReproducer, using a file on a CIFS mount:\n\n\tbash -c '\n\t\tFILE=/mnt/cifs/repro\n\n\t\ttrap \"\" SIGXFSZ\n\t\tulimit -f 3072\t\t# RLIMIT_FSIZE = 3 MiB\n\n\t\t# A regular write is stopped at 3 MiB.\n\t\tdd if=/dev/zero of=\"$FILE\" bs=1M count=4 status=none\n\t\tstat -c \"size after write: %s\" \"$FILE\"\n\n\t\t# Insert 2 MiB into a 2 MiB file.\n\t\ttruncate -s 2M \"$FILE\"\n\t\tfallocate -i -o 0 -l 2M \"$FILE\"\n\t\tstat -c \"size after insert: %s\" \"$FILE\"\n\t'\n\nBefore this change, the regular write stops at the 3 MiB limit, but\ninsert range grows the file to 4 MiB:\n\n\tdd: error writing '/mnt/cifs/repro': File too large\n\tsize after write: 3145728\n\tsize after insert: 4194304\n\nAfter this change, insert range also fails at the limit and leaves the\n2 MiB file unchanged:\n\n\tdd: error writing '/mnt/cifs/repro': File too large\n\tsize after write: 3145728\n\tfallocate: fallocate failed: File too large\n\tsize after insert: 2097152","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98127","source_modified_at":"2026-10-21T12:54:38.540Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"7fe6fe95b936084dce6eedcc2cccadf96eafae73","lessThan":"b7f2e33d9f5db7b8e6e5e0a5a93d0c5e31870356","status":"affected","versionType":"git"},{"version":"7fe6fe95b936084dce6eedcc2cccadf96eafae73","lessThan":"7c2c69045aa76ccaa7f16f1478eb312130ce4951","status":"affected","versionType":"git"},{"version":"7fe6fe95b936084dce6eedcc2cccadf96eafae73","lessThan":"bc7602b9082ef195d913c4c16fa9853dd262333e","status":"affected","versionType":"git"},{"version":"7fe6fe95b936084dce6eedcc2cccadf96eafae73","lessThan":"f8cbfe3a3fcee7d991fd223f660f3e5df13221cf","status":"affected","versionType":"git"},{"version":"7fe6fe95b936084dce6eedcc2cccadf96eafae73","lessThan":"1519dc88c87f5346dae0464d7d6da1b6bf1f6e8e","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98127","source_modified_at":"2026-10-21T12:54:38.540Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"5.13","status":"affected"},{"version":"0","lessThan":"5.13","status":"unaffected","versionType":"semver"},{"version":"6.6.160","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.111","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.53","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.7","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98127","source_modified_at":"2026-10-21T12:54:38.540Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"7c2c69045aa76ccaa7f16f1478eb312130ce4951","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98127","source_modified_at":"2026-10-21T12:54:38.540Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"1519dc88c87f5346dae0464d7d6da1b6bf1f6e8e","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.0013,"percentile":0.0239,"score_date":"2026-10-23"},"published_at":"2026-09-25T10:36:08.406Z","modified_at":"2026-10-21T12:54:38.540Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98127","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-21T12:54:38.540Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98127","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/b7f2e33d9f5db7b8e6e5e0a5a93d0c5e31870356"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/7c2c69045aa76ccaa7f16f1478eb312130ce4951"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/bc7602b9082ef195d913c4c16fa9853dd262333e"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/f8cbfe3a3fcee7d991fd223f660f3e5df13221cf"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/1519dc88c87f5346dae0464d7d6da1b6bf1f6e8e"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-21T12:54:38.540Z","content_hash":"64ae984a437f8964ec58534aec5d3a4a6dda74b67568e38d580d41b449939c03"}}