From: Jeff Layton Date: Tue, 23 Aug 2011 11:21:28 +0000 (-0400) Subject: cifs: fix possible memory corruption in CIFSFindNext X-Git-Tag: v2.6.34.13~160 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9b8bef04268052450e00719b178f1879048a32b5;p=karo-tx-linux.git cifs: fix possible memory corruption in CIFSFindNext 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 Signed-off-by: Jeff Layton Signed-off-by: Steve French Signed-off-by: Paul Gortmaker --- diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 62e49ab50b5e..5171d86c3acb 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -3743,7 +3743,8 @@ int CIFSFindNext(const int xid, struct cifsTconInfo *tcon, 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"));