3.16.62-rc1 review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@oracle.com
commit 2d204ee9d671327915260071c19350d84344e096 upstream.
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 [bwh: Backported to 3.16: Use get_rfc1002_length(rsp) instead of rsp->iov.iov_len] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- fs/cifs/smb2pdu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1394,14 +1394,14 @@ SMB2_ioctl(const unsigned int xid, struc /* 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 > get_rfc1002_length(rsp) || *plen > 0xFF00) { cifs_dbg(VFS, "srv returned invalid ioctl length: %d\n", *plen); *plen = 0; rc = -EIO; goto ioctl_exit; }
- if (get_rfc1002_length(rsp) < le32_to_cpu(rsp->OutputOffset) + *plen) { + if (get_rfc1002_length(rsp) - *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;