{"id":"AZL-100694","summary":"CVE-2026-89637 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix UAF and buffer leak in cifs_check_trans2() for malformed secondary T2\n\nWhen a valid primary TRANSACT2 response has been received (mid-\u003eresp_buf\nset, mid-\u003emultiRsp true) and a subsequent secondary response causes\ncifs_check_trans2() to return false -- either because the SMB header is\ninvalid (malformed != 0) or because check2ndT2() rejects the PDU --\nhandle_mid() overwrites mid-\u003eresp_buf with the new buffer (leaking the\nprimary buffer) and, because mid-\u003emultiRsp is set, skips the\nserver-\u003esmallbuf/bigbuf NULL-out.  When the user thread frees\nmid-\u003eresp_buf, server-\u003esmallbuf or server-\u003ebigbuf is left dangling; the\ndemux thread reuses it for the next packet, resulting in a use-after-free.\n\nCombine both early-exit conditions and, when mid-\u003emultiRsp is already\nset, abort the pending transaction inline: set multiEnd, call\ndequeue_mid() with malformed=true, and return true so handle_mid() exits\nwithout touching mid-\u003eresp_buf or the server buffer pointers.","modified":"2026-09-13T06:06:36Z","published":"2026-09-11T20:19:49Z","upstream":["CVE-2026-89637"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89637"}],"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-100694.json"}}],"schema_version":"1.9.0"}