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authorDan Carpenter <dan.carpenter@oracle.com>2018-09-10 14:12:07 +0300
committerSteve French <stfrench@microsoft.com>2018-09-12 09:32:07 -0500
commit2d204ee9d671327915260071c19350d84344e096 (patch)
treed1ef8c358f51282c7fc382be90af5662872ac882 /fs
parent56446f218af1133c802dad8e9e116f07f381846c (diff)
downloadlinux-2d204ee9d671327915260071c19350d84344e096.tar.bz2
cifs: integer overflow in in SMB2_ioctl()
The "le32_to_cpu(rsp->OutputOffset) + *plen" addition can overflow and wrap around to a smaller value which looks like it would lead to an information leak. Fixes: 4a72dafa19ba ("SMB2 FSCTL and IOCTL worker function") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> CC: Stable <stable@vger.kernel.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/cifs/smb2pdu.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 6f0e6b42599c..f54d07bda067 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2459,14 +2459,14 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
/* We check for obvious errors in the output buffer length and offset */
if (*plen == 0)
goto ioctl_exit; /* server returned no data */
- else if (*plen > 0xFF00) {
+ else if (*plen > rsp_iov.iov_len || *plen > 0xFF00) {
cifs_dbg(VFS, "srv returned invalid ioctl length: %d\n", *plen);
*plen = 0;
rc = -EIO;
goto ioctl_exit;
}
- if (rsp_iov.iov_len < le32_to_cpu(rsp->OutputOffset) + *plen) {
+ if (rsp_iov.iov_len - *plen < le32_to_cpu(rsp->OutputOffset)) {
cifs_dbg(VFS, "Malformed ioctl resp: len %d offset %d\n", *plen,
le32_to_cpu(rsp->OutputOffset));
*plen = 0;