From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42322 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753577AbeBUNIQ (ORCPT ); Wed, 21 Feb 2018 08:08:16 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eugene Syromiatnikov , Heiko Carstens , Martin Schwidefsky Subject: [PATCH 4.15 026/163] s390: fix handling of -1 in set{,fs}[gu]id16 syscalls Date: Wed, 21 Feb 2018 13:47:35 +0100 Message-Id: <20180221124531.659085883@linuxfoundation.org> In-Reply-To: <20180221124529.931834518@linuxfoundation.org> References: <20180221124529.931834518@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eugene Syromiatnikov commit 6dd0d2d22aa363fec075cb2577ba273ac8462e94 upstream. For some reason, the implementation of some 16-bit ID system calls (namely, setuid16/setgid16 and setfsuid16/setfsgid16) used type cast instead of low2highgid/low2highuid macros for converting [GU]IDs, which led to incorrect handling of value of -1 (which ought to be considered invalid). Discovered by strace test suite. Cc: stable@vger.kernel.org Signed-off-by: Eugene Syromiatnikov Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/compat_linux.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -110,7 +110,7 @@ COMPAT_SYSCALL_DEFINE2(s390_setregid16, COMPAT_SYSCALL_DEFINE1(s390_setgid16, u16, gid) { - return sys_setgid((gid_t)gid); + return sys_setgid(low2highgid(gid)); } COMPAT_SYSCALL_DEFINE2(s390_setreuid16, u16, ruid, u16, euid) @@ -120,7 +120,7 @@ COMPAT_SYSCALL_DEFINE2(s390_setreuid16, COMPAT_SYSCALL_DEFINE1(s390_setuid16, u16, uid) { - return sys_setuid((uid_t)uid); + return sys_setuid(low2highuid(uid)); } COMPAT_SYSCALL_DEFINE3(s390_setresuid16, u16, ruid, u16, euid, u16, suid) @@ -173,12 +173,12 @@ COMPAT_SYSCALL_DEFINE3(s390_getresgid16, COMPAT_SYSCALL_DEFINE1(s390_setfsuid16, u16, uid) { - return sys_setfsuid((uid_t)uid); + return sys_setfsuid(low2highuid(uid)); } COMPAT_SYSCALL_DEFINE1(s390_setfsgid16, u16, gid) { - return sys_setfsgid((gid_t)gid); + return sys_setfsgid(low2highgid(gid)); } static int groups16_to_user(u16 __user *grouplist, struct group_info *group_info)