| Date | Sun, 05 Feb 2012 23:10:31 +0100 | From | Willy Tarreau <> | Subject | [PATCH 42/91] cifs: fix possible memory corruption in CIFSFindNext |
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2.6.27-longterm review patch. If anyone has any objections, please let us know.
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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 files changed, 2 insertions(+), 1 deletions(-)
Index: longterm-2.6.27/fs/cifs/cifssmb.c =================================================================== --- longterm-2.6.27.orig/fs/cifs/cifssmb.c 2012-02-05 22:34:33.755917316 +0100 +++ longterm-2.6.27/fs/cifs/cifssmb.c 2012-02-05 22:34:40.813915010 +0100 @@ -3649,7 +3649,8 @@ 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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