From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38753) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAN6K-0002de-LR for qemu-devel@nongnu.org; Wed, 10 Oct 2018 18:37:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAN6H-0000J3-SW for qemu-devel@nongnu.org; Wed, 10 Oct 2018 18:37:08 -0400 Received: from mail-wr1-x433.google.com ([2a00:1450:4864:20::433]:45088) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gAN6G-0000He-Il for qemu-devel@nongnu.org; Wed, 10 Oct 2018 18:37:05 -0400 Received: by mail-wr1-x433.google.com with SMTP id q5-v6so7443782wrw.12 for ; Wed, 10 Oct 2018 15:37:02 -0700 (PDT) Sender: =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Thu, 11 Oct 2018 00:36:47 +0200 Message-Id: <20181010223656.31632-2-f4bug@amsat.org> In-Reply-To: <20181010223656.31632-1-f4bug@amsat.org> References: <20181010223656.31632-1-f4bug@amsat.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH v5 01/10] linux-user/syscall: Verify recvfrom(addr) is user-writable List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Laurent Vivier Cc: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, Riku Voipio , =?UTF-8?q?Guido=20G=C3=BCnther?= Signed-off-by: Philippe Mathieu-Daudé Tested-By: Guido Günther Reviewed-by: Laurent Vivier --- linux-user/syscall.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index ae3c0dfef7..ea503381aa 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -2968,6 +2968,11 @@ static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags, ret = -TARGET_EINVAL; goto fail; } + if (!access_ok(VERIFY_WRITE, target_addr, addrlen)) { + ret = -TARGET_EFAULT; + goto fail; + } + addr = alloca(addrlen); ret = get_errno(safe_recvfrom(fd, host_msg, len, flags, addr, &addrlen)); -- 2.19.1