[tip:x86/urgent] x86/syscalls/64: Add compat_sys_keyctl for 32-bit userspace

[tip-bot for David Howells]

Commit-ID:  f7d665627e103e82d34306c7d3f6f46f387c0d8b
Gitweb:     http://git.kernel.org/tip/f7d665627e103e82d34306c7d3f6f46f387c0d8b
Author:     David Howells <dhowells@xxxxxxxxxx>
AuthorDate: Wed, 27 Jul 2016 11:42:38 +0100
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 1 Aug 2016 11:31:24 +0200

x86/syscalls/64: Add compat_sys_keyctl for 32-bit userspace

x86_64 needs to use compat_sys_keyctl for 32-bit userspace rather than
calling sys_keyctl(). The latter will work in a lot of cases, thereby
hiding the issue.

Reported-by: Stephan Mueller <smueller@xxxxxxxxxx>
Tested-by: Stephan Mueller <smueller@xxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: keyrings@xxxxxxxxxxxxxxx
Cc: linux-security-module@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/146961615805.14395.5581949237156769439.stgit@xxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/entry/syscalls/syscall_32.tbl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 4cddd17..f848572 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -294,7 +294,7 @@
 # 285 sys_setaltroot
 286	i386	add_key			sys_add_key
 287	i386	request_key		sys_request_key
-288	i386	keyctl			sys_keyctl
+288	i386	keyctl			sys_keyctl			compat_sys_keyctl
 289	i386	ioprio_set		sys_ioprio_set
 290	i386	ioprio_get		sys_ioprio_get
 291	i386	inotify_init		sys_inotify_init