{"id":"AZL-100496","summary":"CVE-2026-89631 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: reject a tree connect response whose byte count is too small\n\nCIFSTCon() bounds its strnlen() over the byte area with the server's\nByteCount minus two, which for ByteCount 0 or 1 goes negative as an int\nand converts to a huge size_t.  The later subtraction wraps the __u16\nbytes_left, and that is what bounds cifs_strndup_from_utf16(): a bound of\nup to 65535 against a ~16 KB cifs_req_poolp object runs off the end of the\nslab object, and the bytes reach userspace through tcon-\u003enativeFileSystem\nin /proc/fs/cifs/DebugData.\n\nReject a byte area too small for what the parser consumes.  Two bytes is\nthe least it can consume, and no conformant response carries fewer.  The\nnew trace point is the 129th smb_eio_trace entry, which __mode(byte)\ncannot represent, so the attribute goes with it.","modified":"2026-09-13T06:06:36Z","published":"2026-09-11T20:19:48Z","upstream":["CVE-2026-89631"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89631"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-100496.json"}}],"schema_version":"1.9.0"}