commit 04f8afbec37f63fafce16e454a7848426aa36202
author Tomi Valkeinen <tomi.valkeinen@ti.com> Thu Apr 18 08:39:47 2013 +0300
committer Tomi Valkeinen <tomi.valkeinen@ti.com> Fri Apr 26 08:28:56 2013 +0300
tree 1c761c03f67ebdc71163aaaf0389a092f29916c6
parent 11bd5933abe033fb7a3a0d1f1bd2cb4b6df8143f

fbdev: improve fb_mmap bounds checks

Improve fb_mmap bounds checks in gbefb, smscufx, udlfb and vfb drivers to
prevent possible uint overflows.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Steve Glendinning <steve.glendinning@smsc.com>
Cc: Bernie Thompson <bernie@plugable.com>

drivers/video/gbefb.c

diff --git a/drivers/video/gbefb.c b/drivers/video/gbefb.c
index bda5e39..ceab370 100644
--- a/drivers/video/gbefb.c
+++ b/drivers/video/gbefb.c
@@ -1016,7 +1016,9 @@
 	/* check range */
 	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
 		return -EINVAL;
-	if (offset + size > gbe_mem_size)
+	if (size > gbe_mem_size)
+		return -EINVAL;
+	if (offset > gbe_mem_size - size)
 		return -EINVAL;
 
 	/* remap using the fastest write-through mode on architecture */

drivers/video/smscufx.c

diff --git a/drivers/video/smscufx.c b/drivers/video/smscufx.c
index 97bd662..b2b33fc 100644
--- a/drivers/video/smscufx.c
+++ b/drivers/video/smscufx.c
@@ -782,7 +782,11 @@
 	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 	unsigned long page, pos;
 
-	if (offset + size > info->fix.smem_len)
+	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
+		return -EINVAL;
+	if (size > info->fix.smem_len)
+		return -EINVAL;
+	if (offset > info->fix.smem_len - size)
 		return -EINVAL;
 
 	pos = (unsigned long)info->fix.smem_start + offset;

drivers/video/udlfb.c

diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c
index 86d449e..ec03e72 100644
--- a/drivers/video/udlfb.c
+++ b/drivers/video/udlfb.c
@@ -324,7 +324,11 @@
 	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 	unsigned long page, pos;
 
-	if (offset + size > info->fix.smem_len)
+	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
+		return -EINVAL;
+	if (size > info->fix.smem_len)
+		return -EINVAL;
+	if (offset > info->fix.smem_len - size)
 		return -EINVAL;
 
 	pos = (unsigned long)info->fix.smem_start + offset;

drivers/video/vfb.c

diff --git a/drivers/video/vfb.c b/drivers/video/vfb.c
index 8bc1f93..ee5985e 100644
--- a/drivers/video/vfb.c
+++ b/drivers/video/vfb.c
@@ -420,9 +420,12 @@
 	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 	unsigned long page, pos;
 
-	if (offset + size > info->fix.smem_len) {
+	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
 		return -EINVAL;
-	}
+	if (size > info->fix.smem_len)
+		return -EINVAL;
+	if (offset > info->fix.smem_len - size)
+		return -EINVAL;
 
 	pos = (unsigned long)info->fix.smem_start + offset;