| From 9438fabb73eb48055b58b89fc51e0bc4db22fabd Mon Sep 17 00:00:00 2001 |
| From: Jeff Layton <jlayton@redhat.com> |
| Date: Tue, 23 Aug 2011 07:21:28 -0400 |
| Subject: cifs: fix possible memory corruption in CIFSFindNext |
| |
| From: Jeff Layton <jlayton@redhat.com> |
| |
| commit 9438fabb73eb48055b58b89fc51e0bc4db22fabd upstream. |
| |
| The name_len variable in CIFSFindNext is a signed int that gets set to |
| the resume_name_len in the cifs_search_info. The resume_name_len however |
| is unsigned and for some infolevels is populated directly from a 32 bit |
| value sent by the server. |
| |
| If the server sends a very large value for this, then that value could |
| look negative when converted to a signed int. That would make that |
| value pass the PATH_MAX check later in CIFSFindNext. The name_len would |
| then be used as a length value for a memcpy. It would then be treated |
| as unsigned again, and the memcpy scribbles over a ton of memory. |
| |
| Fix this by making the name_len an unsigned value in CIFSFindNext. |
| |
| Reported-by: Darren Lavender <dcl@hppine99.gbr.hp.com> |
| Signed-off-by: Jeff Layton <jlayton@redhat.com> |
| Signed-off-by: Steve French <sfrench@us.ibm.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| fs/cifs/cifssmb.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/fs/cifs/cifssmb.c |
| +++ b/fs/cifs/cifssmb.c |
| @@ -3596,7 +3596,8 @@ int CIFSFindNext(const int xid, struct c |
| T2_FNEXT_RSP_PARMS *parms; |
| char *response_data; |
| int rc = 0; |
| - int bytes_returned, name_len; |
| + int bytes_returned; |
| + unsigned int name_len; |
| __u16 params, byte_count; |
| |
| cFYI(1, ("In FindNext")); |
