From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46040) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fV5iD-0001op-Ln for qemu-devel@nongnu.org; Mon, 18 Jun 2018 21:45:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fV5iC-0008Uk-Ph for qemu-devel@nongnu.org; Mon, 18 Jun 2018 21:45:37 -0400 Sender: fluxion From: Michael Roth Date: Mon, 18 Jun 2018 20:42:07 -0500 Message-Id: <20180619014319.28272-42-mdroth@linux.vnet.ibm.com> In-Reply-To: <20180619014319.28272-1-mdroth@linux.vnet.ibm.com> References: <20180619014319.28272-1-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 041/113] multiboot: Check validity of mh_header_addr List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Kevin Wolf From: Kevin Wolf I couldn't find a case where this prevents something bad from happening that isn't already caught by other checks, but let's err on the safe side and check that mh_header_addr is as expected. Signed-off-by: Kevin Wolf Reviewed-by: Jack Schwartz (cherry picked from commit dbf2dce7aabb7723542bd182175904846d70b0f9) Signed-off-by: Michael Roth --- hw/i386/multiboot.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c index 775aa5bfd0..36b22832cd 100644 --- a/hw/i386/multiboot.c +++ b/hw/i386/multiboot.c @@ -229,6 +229,10 @@ int load_multiboot(FWCfgState *fw_cfg, error_report("invalid load_addr address"); exit(1); } + if (mh_header_addr - mh_load_addr > i) { + error_report("invalid header_addr address"); + exit(1); + } uint32_t mb_kernel_text_offset = i - (mh_header_addr - mh_load_addr); uint32_t mb_load_size = 0; -- 2.11.0