From dc608d46455f2a246015122633c5cd143e9e6983 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 ddde1a77a34e ("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: ddde1a77a34e ("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 --- 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 6352ab32c7e7a..223056097b54f 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1169,9 +1169,9 @@ 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, -- 2.39.5