{"id":"AZL-85445","summary":"CVE-2026-31708 affecting package kernel for versions less than 6.6.137.1-2","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path\n\nsmb2_ioctl_query_info() has two response-copy branches: PASSTHRU_FSCTL\nand the default QUERY_INFO path.  The QUERY_INFO branch clamps\nqi.input_buffer_length to the server-reported OutputBufferLength and then\ncopies qi.input_buffer_length bytes from qi_rsp-\u003eBuffer to userspace, but\nit never verifies that the flexible-array payload actually fits within\nrsp_iov[1].iov_len.\n\nA malicious server can return OutputBufferLength larger than the actual\nQUERY_INFO response, causing copy_to_user() to walk past the response\nbuffer and expose adjacent kernel heap to userspace.\n\nGuard the QUERY_INFO copy with a bounds check on the actual Buffer\npayload.  Use struct_size(qi_rsp, Buffer, qi.input_buffer_length)\nrather than an open-coded addition so the guard cannot overflow on\n32-bit builds.","modified":"2026-08-28T17:47:43.739586612Z","published":"2026-05-01T14:16:20Z","upstream":["CVE-2026-31708"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31708"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.137.1-2"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-85445.json"}}],"schema_version":"1.9.0"}