From: Eugene Syromiatnikov Date: Mon, 15 Jan 2018 19:38:17 +0000 (+0100) Subject: s390: fix handling of -1 in set{,fs}[gu]id16 syscalls X-Git-Tag: v3.2.102~94 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f064e3c7e09390ea48a5fbda0528e145fba432b5;p=thirdparty%2Fkernel%2Fstable.git 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. Signed-off-by: Eugene Syromiatnikov Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c index 76fdbad69e979..93ce6deef5a95 100644 --- a/arch/s390/kernel/compat_linux.c +++ b/arch/s390/kernel/compat_linux.c @@ -114,7 +114,7 @@ asmlinkage long sys32_setregid16(u16 rgid, u16 egid) asmlinkage long sys32_setgid16(u16 gid) { - return sys_setgid((gid_t)gid); + return sys_setgid(low2highgid(gid)); } asmlinkage long sys32_setreuid16(u16 ruid, u16 euid) @@ -124,7 +124,7 @@ asmlinkage long sys32_setreuid16(u16 ruid, u16 euid) asmlinkage long sys32_setuid16(u16 uid) { - return sys_setuid((uid_t)uid); + return sys_setuid(low2highuid(uid)); } asmlinkage long sys32_setresuid16(u16 ruid, u16 euid, u16 suid) @@ -163,12 +163,12 @@ asmlinkage long sys32_getresgid16(u16 __user *rgid, u16 __user *egid, u16 __user asmlinkage long sys32_setfsuid16(u16 uid) { - return sys_setfsuid((uid_t)uid); + return sys_setfsuid(low2highuid(uid)); } asmlinkage long sys32_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)