s390: fix handling of -1 in set{,fs}[gu]id16 syscalls (6dd0d2d2) · Commits · 戴 / test

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 <esyr@redhat.com> Signed-off-by:

Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/compat_linux.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -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)

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