4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dave Martin <dave.mar...@arm.com>
commit a672401c00f82e4e19704aff361d9bad18003714 upstream.
Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.
Fixes: 5d220ff9420f ("arm64: Better native ptrace support for compat tasks")
Signed-off-by: Dave Martin <dave.mar...@arm.com>
Acked-by: Will Deacon <will.dea...@arm.com>
Signed-off-by: Catalin Marinas <catalin.mari...@arm.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/arm64/kernel/ptrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -949,7 +949,7 @@ static int compat_tls_set(struct task_st
const void __user *ubuf)
{
int ret;
- compat_ulong_t tls;
+ compat_ulong_t tls = target->thread.tp_value;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
if (ret)
