From: Khem Raj <raj.khem@gmail.com>
Date: Fri, 2 Mar 2018 04:45:48 +0000 (+1100)
Subject: powerpc/ptrace: Fix out of bounds array access warning
X-Git-Tag: v4.1.50~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f1d035422a54914c03aebda611ad3f6b3ecf0636;p=thirdparty%2Fkernel%2Fstable.git

powerpc/ptrace: Fix out of bounds array access warning

commit 1e407ee3b21f981140491d5b8a36422979ca246f upstream.

gcc-6 correctly warns about a out of bounds access

arch/powerpc/kernel/ptrace.c:407:24: warning: index 32 denotes an offset greater than size of 'u64[32][1] {aka long long unsigned int[32][1]}' [-Warray-bounds]
        offsetof(struct thread_fp_state, fpr[32][0]));
                        ^

check the end of array instead of beginning of next element to fix this

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index f21897b420576..93f200f14e197 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -376,7 +376,7 @@ static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 
 #else
 	BUILD_BUG_ON(offsetof(struct thread_fp_state, fpscr) !=
-		     offsetof(struct thread_fp_state, fpr[32][0]));
+		     offsetof(struct thread_fp_state, fpr[32]));
 
 	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 				   &target->thread.fp_state, 0, -1);
@@ -404,7 +404,7 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 	return 0;
 #else
 	BUILD_BUG_ON(offsetof(struct thread_fp_state, fpscr) !=
-		     offsetof(struct thread_fp_state, fpr[32][0]));
+		     offsetof(struct thread_fp_state, fpr[32]));
 
 	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 				  &target->thread.fp_state, 0, -1);