From 60480291c1fcafad8425d93f771b5bcc2bd398b4 Mon Sep 17 00:00:00 2001 From: Zhang Xiaoxu Date: Mon, 26 Sep 2022 11:36:29 +0800 Subject: [PATCH] cifs: Fix the error length of VALIDATE_NEGOTIATE_INFO message commit e98ecc6e94f4e6d21c06660b0f336df02836694f upstream. Commit d5c7076b772a ("smb3: add smb3.1.1 to default dialect list") extend the dialects from 3 to 4, but forget to decrease the extended length when specific the dialect, then the message length is larger than expected. This maybe leak some info through network because not initialize the message body. After apply this patch, the VALIDATE_NEGOTIATE_INFO message length is reduced from 28 bytes to 26 bytes. Fixes: d5c7076b772a ("smb3: add smb3.1.1 to default dialect list") Signed-off-by: Zhang Xiaoxu Cc: Acked-by: Paulo Alcantara (SUSE) Reviewed-by: Tom Talpey Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/smb2pdu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index a423d14..cf8e85d 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1137,9 +1137,9 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon) pneg_inbuf->Dialects[0] = cpu_to_le16(server->vals->protocol_id); pneg_inbuf->DialectCount = cpu_to_le16(1); - /* structure is big enough for 3 dialects, sending only 1 */ + /* structure is big enough for 4 dialects, sending only 1 */ inbuflen = sizeof(*pneg_inbuf) - - sizeof(pneg_inbuf->Dialects[0]) * 2; + sizeof(pneg_inbuf->Dialects[0]) * 3; } rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID, -- 2.7.4