{"id":"CVE-2026-99274","published":"2026-11-07T14:17:02.730","lastModified":"2026-11-10T19:22:31.327","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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/31f6dbb29fe17fa9595c7e8b19fd92915b03a4ca","tags":[]},{"url":"https://git.kernel.org/stable/c/4a426ca5be7e3dedbe76575b967db04fbf01136f","tags":[]},{"url":"https://git.kernel.org/stable/c/8e0d425b808c367f5033eb72aa4528ae18473627","tags":[]},{"url":"https://git.kernel.org/stable/c/f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}