{"affected":[{"defaultStatus":"unaffected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"lessThan":"4a426ca5be7e3dedbe76575b967db04fbf01136f","status":"affected","version":"2f3ebaba13cebd8badfb9aed31c0cf3cc82eb4f4","versionType":"git"},{"lessThan":"31f6dbb29fe17fa9595c7e8b19fd92915b03a4ca","status":"affected","version":"2f3ebaba13cebd8badfb9aed31c0cf3cc82eb4f4","versionType":"git"},{"lessThan":"f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc","status":"affected","version":"2f3ebaba13cebd8badfb9aed31c0cf3cc82eb4f4","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"status":"affected","version":"5.2"},{"lessThan":"5.2","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.61","versionType":"semver"},{"lessThanOrEqual":"7.3.*","status":"unaffected","version":"7.3.2","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.4-rc1","versionType":"original_commit_for_fix"}]}],"cveId":"CVE-2026-99274","cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix fiemap wild read on empty truncated response\n\nsmb3_fiemap() treats -E2BIG from SMB2_ioctl() as a truncated range blob\nand loops for the next chunk. If the server reports\nSTATUS_BUFFER_OVERFLOW with OutputCount == 0, SMB2_ioctl() returns\n-E2BIG with out_data == NULL and out_data_len == 0, and the existing\nlength checks accept the empty result. The loop then evaluates\n\n\tnext = out_data[num - 1].file_offset + ...\n\nwith num == 0, reading 16 bytes before NULL.\n\nReject a truncated range blob that contains no range, so the resume\noffset is never computed from an empty response. Also require the last\nrange in a truncated blob to advance the resume offset without\noverflowing, and to stay within the requested range; a malicious or\nbroken server could otherwise make no progress or underflow len and loop\nforever. Free the previous response buffer before retrying.\n\nReproduced on 6.6.87.2 with a malicious SMB2 server that answers\nFSCTL_QUERY_ALLOCATED_RANGES with STATUS_BUFFER_OVERFLOW and\nOutputCount == 0; an FS_IOC_FIEMAP ioctl on the mount oopses in\ncifs_fiemap() with CR2 = fffffffffffffff8. The code path is unchanged\non mainline.","epss":null,"exploits":[],"kev":null,"metrics":[],"modifiedAt":1794060525924,"publishedAt":1794060525924,"references":[{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/4a426ca5be7e3dedbe76575b967db04fbf01136f"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/31f6dbb29fe17fa9595c7e8b19fd92915b03a4ca"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc"}],"remediation":[],"revision":"c21dd7abc902b91d6dfcca7b691f79be985bbba8d422b9896c8e7930d3c6c3e5","sources":[{"modifiedAt":1794060525924,"name":"CNA: Linux","retrievedAt":1794064153094,"url":"https://www.cve.org/CVERecord?id=CVE-2026-99274"}],"ssvc":null,"status":"published","title":"smb: client: fix fiemap wild read on empty truncated response","updatedAt":1794064153094}