From patchwork Thu Feb 7 14:51:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Schwab X-Patchwork-Id: 1038117 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.de Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43wLsQ2lhcz9s9G for ; Fri, 8 Feb 2019 01:53:14 +1100 (AEDT) Received: from localhost ([127.0.0.1]:41451 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1grl3A-0006y3-3P for incoming@patchwork.ozlabs.org; Thu, 07 Feb 2019 09:53:12 -0500 Received: from eggs.gnu.org ([209.51.188.92]:42165) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1grl1o-0006bR-5b for qemu-devel@nongnu.org; Thu, 07 Feb 2019 09:51:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1grl1k-0005GT-EE for qemu-devel@nongnu.org; Thu, 07 Feb 2019 09:51:47 -0500 Received: from mx2.suse.de ([195.135.220.15]:56596 helo=mx1.suse.de) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1grl1j-0005DR-Qb for qemu-devel@nongnu.org; Thu, 07 Feb 2019 09:51:44 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 3013EB007; Thu, 7 Feb 2019 14:51:37 +0000 (UTC) From: Andreas Schwab To: qemu-devel@nongnu.org X-Yow: Tex SEX! The HOME of WHEELS! The dripping of COFFEE!! Take me to Minnesota but don't EMBARRASS me!! Date: Thu, 07 Feb 2019 15:51:35 +0100 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1.91 (gnu/linux) MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] X-Received-From: 195.135.220.15 Subject: [Qemu-devel] [PATCH] linux-user: fix emulation of accept4/getpeername/getsockname/recvfrom syscalls X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Riku Voipio , Laurent Vivier Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" System calls that return a socket address do so by writing the (possibly truncated) address into the provided buffer space, but setting the addrlen parameter to the actual size of the address. To determine how much to copy back to the target memory the emulation needs to remember the old value of the addrlen parameter, so that it doesn't write past the buffer limits. Signed-off-by: Andreas Schwab Reviewed-by: Laurent Vivier --- linux-user/syscall.c | 38 ++++++++++++++++++++++---------------- 1 file changed, 22 insertions(+), 16 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 55fa235a56..90bfda3563 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -2884,7 +2884,7 @@ static abi_long do_sendrecvmmsg(int fd, abi_ulong target_msgvec, static abi_long do_accept4(int fd, abi_ulong target_addr, abi_ulong target_addrlen_addr, int flags) { - socklen_t addrlen; + socklen_t addrlen, ret_addrlen; void *addr; abi_long ret; int host_flags; @@ -2908,10 +2908,11 @@ static abi_long do_accept4(int fd, abi_ulong target_addr, addr = alloca(addrlen); - ret = get_errno(safe_accept4(fd, addr, &addrlen, host_flags)); + ret_addrlen = addrlen; + ret = get_errno(safe_accept4(fd, addr, &ret_addrlen, host_flags)); if (!is_error(ret)) { - host_to_target_sockaddr(target_addr, addr, addrlen); - if (put_user_u32(addrlen, target_addrlen_addr)) + host_to_target_sockaddr(target_addr, addr, MIN(addrlen, ret_addrlen)); + if (put_user_u32(ret_addrlen, target_addrlen_addr)) ret = -TARGET_EFAULT; } return ret; @@ -2921,7 +2922,7 @@ static abi_long do_accept4(int fd, abi_ulong target_addr, static abi_long do_getpeername(int fd, abi_ulong target_addr, abi_ulong target_addrlen_addr) { - socklen_t addrlen; + socklen_t addrlen, ret_addrlen; void *addr; abi_long ret; @@ -2937,10 +2938,11 @@ static abi_long do_getpeername(int fd, abi_ulong target_addr, addr = alloca(addrlen); - ret = get_errno(getpeername(fd, addr, &addrlen)); + ret_addrlen = addrlen; + ret = get_errno(getpeername(fd, addr, &ret_addrlen)); if (!is_error(ret)) { - host_to_target_sockaddr(target_addr, addr, addrlen); - if (put_user_u32(addrlen, target_addrlen_addr)) + host_to_target_sockaddr(target_addr, addr, MIN(addrlen, ret_addrlen)); + if (put_user_u32(ret_addrlen, target_addrlen_addr)) ret = -TARGET_EFAULT; } return ret; @@ -2950,7 +2952,7 @@ static abi_long do_getpeername(int fd, abi_ulong target_addr, static abi_long do_getsockname(int fd, abi_ulong target_addr, abi_ulong target_addrlen_addr) { - socklen_t addrlen; + socklen_t addrlen, ret_addrlen; void *addr; abi_long ret; @@ -2966,10 +2968,11 @@ static abi_long do_getsockname(int fd, abi_ulong target_addr, addr = alloca(addrlen); - ret = get_errno(getsockname(fd, addr, &addrlen)); + ret_addrlen = addrlen; + ret = get_errno(getsockname(fd, addr, &ret_addrlen)); if (!is_error(ret)) { - host_to_target_sockaddr(target_addr, addr, addrlen); - if (put_user_u32(addrlen, target_addrlen_addr)) + host_to_target_sockaddr(target_addr, addr, MIN(addrlen, ret_addrlen)); + if (put_user_u32(ret_addrlen, target_addrlen_addr)) ret = -TARGET_EFAULT; } return ret; @@ -3042,7 +3045,7 @@ static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags, abi_ulong target_addr, abi_ulong target_addrlen) { - socklen_t addrlen; + socklen_t addrlen, ret_addrlen; void *addr; void *host_msg; abi_long ret; @@ -3060,10 +3063,12 @@ static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags, goto fail; } addr = alloca(addrlen); + ret_addrlen = addrlen; ret = get_errno(safe_recvfrom(fd, host_msg, len, flags, - addr, &addrlen)); + addr, &ret_addrlen)); } else { addr = NULL; /* To keep compiler quiet. */ + addrlen = 0; /* To keep compiler quiet. */ ret = get_errno(safe_recvfrom(fd, host_msg, len, flags, NULL, 0)); } if (!is_error(ret)) { @@ -3076,8 +3081,9 @@ static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags, } } if (target_addr) { - host_to_target_sockaddr(target_addr, addr, addrlen); - if (put_user_u32(addrlen, target_addrlen)) { + host_to_target_sockaddr(target_addr, addr, + MIN(addrlen, ret_addrlen)); + if (put_user_u32(ret_addrlen, target_addrlen)) { ret = -TARGET_EFAULT; goto fail; }