From: Zhang Xiaoxu zhangxiaoxu5@huawei.com
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 zhangxiaoxu5@huawei.com Cc: stable@vger.kernel.org Acked-by: Paulo Alcantara (SUSE) pc@cjr.nz Reviewed-by: Tom Talpey tom@talpey.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/cifs/smb2pdu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1169,9 +1169,9 @@ int smb3_validate_negotiate(const unsign 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,