From 1714a066d71dc00bc336aa1565ec86551e388704 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 30 Aug 2017 16:30:35 +0300
Subject: [PATCH] scsi: qla2xxx: Fix an integer overflow in sysfs code

commit e6f77540c067b48dee10f1e33678415bfcc89017 upstream.

The value of "size" comes from the user.  When we add "start + size" it
could lead to an integer overflow bug.

It means we vmalloc() a lot more memory than we had intended.  I believe
that on 64 bit systems vmalloc() can succeed even if we ask it to
allocate huge 4GB buffers.  So we would get memory corruption and likely
a crash when we call ha->isp_ops->write_optrom() and ->read_optrom().

Only root can trigger this bug.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=194061

Fixes: b7cc176c9eb3 ("[SCSI] qla2xxx: Allow region-based flash-part accesses.")
Reported-by: shqking <shqking@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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