[gdk-pixbuf] bmp: Reject bogus depth

[Matthias Clasen <matthiasc src gnome org>]

commit ca74893a8e06e99b4adc682ee1550bfd020687c7
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Dec 5 15:49:32 2015 -0500

    bmp: Reject bogus depth
    
    Erroring out early if we find a bogus image depth is
    the right thing to do, and avoids possible memory
    overruns later on.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=747605

 gdk-pixbuf/io-bmp.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/gdk-pixbuf/io-bmp.c b/gdk-pixbuf/io-bmp.c
index 1f197e8..5c30bfb 100644
--- a/gdk-pixbuf/io-bmp.c
+++ b/gdk-pixbuf/io-bmp.c
@@ -318,6 +318,15 @@ static gboolean DecodeHeader(unsigned char *BFH, unsigned char *BIH,
                return FALSE;
        }
 
+        if (State->Header.depth > 32)
+          {
+               g_set_error_literal (error,
+                                     GDK_PIXBUF_ERROR,
+                                     GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
+                                     _("BMP image has unsupported depth"));
+               State->read_state = READ_STATE_ERROR;
+          }
+
        if (State->Header.size == 12)
                clrUsed = 1 << State->Header.depth;
        else