From 1767f904c44076c1b049eb540c6b565aac787bc3 Mon Sep 17 00:00:00 2001 From: Sergio Lopez Pascual Date: Mon, 15 Apr 2019 11:38:00 +0100 Subject: [PATCH] device_tree: Fix integer overflowing in load_device_tree() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Sergio Lopez Pascual Message-id: <20190415113800.48669-2-slp@redhat.com> Patchwork-id: 85667 O-Subject: [RHEL-8.0 qemu-kvm PATCH 1/1] device_tree: Fix integer overflowing in load_device_tree() Bugzilla: 1693116 RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Stefano Garzarella From: Markus Armbruster 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: Kurtis Miller Signed-off-by: Markus Armbruster Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Alistair Francis Message-Id: <20190409174018.25798-1-armbru@redhat.com> (cherry picked from 065e6298a75164b4347682b63381dbe752c2b156) Signed-off-by: Sergio Lopez Signed-off-by: Danilo C. L. de Paula --- device_tree.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/device_tree.c b/device_tree.c index 19458b3..2457f58 100644 --- a/device_tree.c +++ b/device_tree.c @@ -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; -- 1.8.3.1