Messages in this thread Patch in this message | | | From | Paul Gortmaker <> | Subject | [v2.6.34-stable 010/165] cifs: fix possible memory corruption in CIFSFindNext | Date | Wed, 15 Aug 2012 15:45:54 -0400 |
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From: Jeff Layton <jlayton@redhat.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
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: Paul Gortmaker <paul.gortmaker@windriver.com> --- fs/cifs/cifssmb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 62e49ab..5171d86 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")); -- 1.7.12.rc2
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