From: Frantisek Hrbata <fhrbata@redhat.com>
Date: Thu, 11 Nov 2010 12:55:53 -0500
Subject: [scsi] gdth: prevent integer overflow in ioc_general
Message-id: <1289480153-6542-1-git-send-email-fhrbata@redhat.com>
Patchwork-id: 29143
O-Subject: [PATCH RHEL5.6 BZ651176 - CVE-2010-4157] scsi: gdth: integer overflow
	in ioc_general()
Bugzilla: 651176
RH-Acked-by: Jiri Pirko <jpirko@redhat.com>

Bug: 651176
https://bugzilla.redhat.com/show_bug.cgi?id=651176

Brew build: 2886748
https://brewweb.devel.redhat.com/taskinfo?taskID=2886748

Description:
gdth_ioctl_alloc() takes the size variable as an int. copy_from_user() takes
the size variable as an unsigned long. gen.data_len and gen.sense_len are
unsigned longs. On x86_64 longs are 64 bit and ints are 32 bit.

We could pass in a very large number and the allocation would truncate the size
to 32 bits and allocate a small buffer.  Then when we do the copy_from_user(),
it would result in a memory corruption.

Upstream Status:
backport of 2.6 commit f63ae56e4e97fb12053590e41a4fa59e7daa74a4

Test Status:
Not tested, since I have not been able to locate any machine with required
hardware yet. To test this we need a 64bit machine with some ICP vortex GDT RAID
Controller using the gdth driver. I will keep searching and if I find such HW I
will test it. The patch is pretty straightforward. If I overlooked such machine
in beaker or you know about one, please let me know.

Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>

diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
index e0d487b..ad7442e 100644
--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -5098,6 +5098,14 @@ static int ioc_general(void __user *arg, char *cmnd)
     if (copy_from_user(&gen, arg, sizeof(gdth_ioctl_general)) ||
         gen.ionode >= gdth_ctr_count)
         return -EFAULT;
+
+    if (gen.data_len > INT_MAX)
+        return -EINVAL;
+    if (gen.sense_len > INT_MAX)
+        return -EINVAL;
+    if (gen.data_len + gen.sense_len > INT_MAX)
+        return -EINVAL;
+
     hanum = gen.ionode; 
     ha = HADATA(gdth_ctr_tab[hanum]);
     if (gen.data_len + gen.sense_len != 0) {