[04/20] [SCSI] gdth: Prevent negative offsets in ioctl CVE-2009-3080

[Greg KH <gregkh@suse.de>]

[-- Attachment #1: gdth-prevent-negative-offsets-in-ioctl-cve-2009-3080.patch --]
[-- Type: text/plain, Size: 869 bytes --]

2.6.27-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Dave Jones <davej@redhat.com>

commit 690e744869f3262855b83b4fb59199cf142765b0 upstream.

A negative offset could be used to index before the event buffer and
lead to a security breach.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/scsi/gdth.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -2912,7 +2912,7 @@ static int gdth_read_event(gdth_ha_str *
         eindex = handle;
     estr->event_source = 0;
 
-    if (eindex >= MAX_EVENTS) {
+    if (eindex < 0 || eindex >= MAX_EVENTS) {
         spin_unlock_irqrestore(&ha->smp_lock, flags);
         return eindex;
     }