Commit 065e6298 authored by Markus Armbruster's avatar Markus Armbruster Committed by Alistair Francis
Browse files

device_tree: Fix integer overflowing in load_device_tree() 



If the value of get_image_size() exceeds INT_MAX / 2 - 10000, the
computation of @dt_size overflows to a negative number, which then
gets converted to a very large size_t for g_malloc0() and
load_image_size().  In the (fortunately improbable) case g_malloc0()
succeeds and load_image_size() survives, we'd assign the negative
number to *sizep.  What that would do to the callers I can't say, but
it's unlikely to be good.

Fix by rejecting images whose size would overflow.

Reported-by: default avatarKurtis Miller <kurtis.miller@nccgroup.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: default avatarAlistair Francis <alistair.francis@wdc.com>
Message-Id: <20190409174018.25798-1-armbru@redhat.com>
parent f151f8ac

device_tree.c

+4 −0
Original line number Diff line number Diff line
@@ -84,6 +84,10 @@ void *load_device_tree(const char *filename_path, int *sizep) 
                     filename_path);

        goto fail;

    }

    if (dt_size > INT_MAX / 2 - 10000) {

        error_report("Device tree file '%s' is too large", filename_path);

        goto fail;

    }



    /* Expand to 2x size to give enough room for manipulation.  */

    dt_size += 10000;