Messages in this thread Patch in this message |  | | | Date | Wed, 02 Nov 2011 15:26:12 -0700 | | From | Greg KH <> | | Subject | [028/101] cifs: fix possible memory corruption in CIFSFindNext |
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2.6.33-longterm review patch. If anyone has any objections, please let us know.
------------------ 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"));
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