{"id":"CVE-2026-99272","title":"smb: client: validate the data area in SMB2_read()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate the data area in SMB2_read()\n\nSMB2_read() copies le32_to_cpu(rsp->DataLength) bytes from\n(char *)rsp + rsp->DataOffset without checking that the r…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= d8e050398d23ef7c019c96200b80d73f4e5cec0c < 1ba1937de005e261a8858f45bfef5da7458df94c","Linux >= d8e050398d23ef7c019c96200b80d73f4e5cec0c < 2ec9cdf469dd32bcf33073aeb30c08e9356e0ca1","Linux 3.7"],"published":"2026-11-07","updated":"2026-11-07","sourceUpdated":"2026-11-07T14:08:45.332Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99272","references":[{"url":"https://git.kernel.org/stable/c/1ba1937de005e261a8858f45bfef5da7458df94c"},{"url":"https://git.kernel.org/stable/c/2ec9cdf469dd32bcf33073aeb30c08e9356e0ca1"}],"tags":["cve.org"],"ingestedAt":"2026-11-07T14:18:21.467Z","slug":"CVE-2026-99272","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate the data area in SMB2_read()\n\nSMB2_read() copies le32_to_cpu(rsp->DataLength) bytes from\n(char *)rsp + rsp->DataOffset without checking that the range lies\nwithin the response actually received. A READ response with\nDataOffset == 0 makes smb2_get_data_area_len() zero the data length, so\nsmb2_check_message() accepts a frame as short as the fixed response,\nwhile SMB2_read() still uses the server-supplied DataLength, capped only\nby CIFS_MAX_MSGSIZE and the caller's length.\n\nA malicious server can answer the synchronous read used by the\nmfsymlinks (or SFU) symlink parser with an 81-byte READ response\ncarrying DataOffset 0 and DataLength 1067, making the client copy 1067\nbytes from a 448-byte receive object (KASAN slab-out-of-bounds; up to\n16 KiB in the general case).\n\nClamp a zero (or header-overlapping) DataOffset to read_rsp_size, as\nhandle_read_data() does for the asynchronous path, and reject the\nresponse unless DataOffset + DataLength fits within rsp_iov.iov_len.\nThe SMB1 helper was fixed the same way in 5be5bdda5863.\n\n## Affected\n\n- `Linux >= d8e050398d23ef7c019c96200b80d73f4e5cec0c < 1ba1937de005e261a8858f45bfef5da7458df94c`\n- `Linux >= d8e050398d23ef7c019c96200b80d73f4e5cec0c < 2ec9cdf469dd32bcf33073aeb30c08e9356e0ca1`\n- `Linux 3.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}