From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51062) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eeKgi-0003Jt-1H for qemu-devel@nongnu.org; Wed, 24 Jan 2018 08:02:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eeKgc-0005am-Jb for qemu-devel@nongnu.org; Wed, 24 Jan 2018 08:02:00 -0500 Received: from mail-qt0-x241.google.com ([2607:f8b0:400d:c0d::241]:46704) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1eeKgc-0005ab-Fa for qemu-devel@nongnu.org; Wed, 24 Jan 2018 08:01:54 -0500 Received: by mail-qt0-x241.google.com with SMTP id o35so9976201qtj.13 for ; Wed, 24 Jan 2018 05:01:54 -0800 (PST) Sender: =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Wed, 24 Jan 2018 10:01:25 -0300 Message-Id: <20180124130126.20871-11-f4bug@amsat.org> In-Reply-To: <20180124130126.20871-1-f4bug@amsat.org> References: <20180124130126.20871-1-f4bug@amsat.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH 10/11] linux-user/syscall: verify recvfrom(addr) is user-writable List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Riku Voipio , Laurent Vivier Cc: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, =?UTF-8?q?Guido=20G=C3=BCnther?= Signed-off-by: Philippe Mathieu-Daudé --- linux-user/syscall.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 11c9116c4a..b6b9beca5b 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -4040,6 +4040,11 @@ 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)); -- 2.15.1