From 27f97375fcb86750cdf82a65dab8174bb991c238 Mon Sep 17 00:00:00 2001 From: Eugene Syromiatnikov Date: Mon, 15 Jan 2018 20:38:17 +0100 Subject: [PATCH] s390: fix handling of -1 in set{,fs}[gu]id16 syscalls 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(-) diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c index 59eea9c65d3e..79b7a3438d54 100644 --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -110,7 +110,7 @@ COMPAT_SYSCALL_DEFINE2(s390_setregid16, u16, rgid, u16, egid) 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, u16, ruid, u16, euid) 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, u16 __user *, rgidp, 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) -- 2.20.1