From bf2afee14e07de16d3cafc67edbfc2a3cc65e4bc Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Fri, 8 Sep 2017 10:37:35 +1000 Subject: [PATCH] cifs: check rsp for NULL before dereferencing in SMB2_open In SMB2_open there are several paths where the SendReceive2 call will return an error before it sets rsp_iov.iov_base thus leaving iov_base uninitialized. Thus we need to check rsp before we dereference it in the call to get_rfc1002_length(). A report of this issue was previously reported in http://www.spinics.net/lists/linux-cifs/msg12846.html RH-bugzilla : 1476151 Version 2 : * Lets properly initialize rsp_iov before we use it. Signed-off-by: Ronnie Sahlberg Reviewed-by: Pavel Shilovsky . Signed-off-by: Steve French Reported-by: Xiaoli Feng CC: Stable --- 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 5531e7ee1210..69a751b038ab 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1634,7 +1634,7 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path, struct cifs_tcon *tcon = oparms->tcon; struct cifs_ses *ses = tcon->ses; struct kvec iov[4]; - struct kvec rsp_iov; + struct kvec rsp_iov = {NULL, 0}; int resp_buftype; int uni_path_len; __le16 *copy_path = NULL; @@ -1763,7 +1763,7 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path, if (rc != 0) { cifs_stats_fail_inc(tcon, SMB2_CREATE_HE); - if (err_buf) + if (err_buf && rsp) *err_buf = kmemdup(rsp, get_rfc1002_length(rsp) + 4, GFP_KERNEL); goto creat_exit; -- 2.20.1