[PATCH v2 06/12] ptrace: Reimplement PTRACE_KILL by always sending SIGKILL

["Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>]

Call send_sig_info in PTRACE_KILL instead of ptrace_resume.  Calling
ptrace_resume is not safe to call if the task has not been stopped
with ptrace_freeze_traced.

Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Suggested-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
 kernel/ptrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index ccc4b465775b..43da5764b6f3 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -1238,7 +1238,7 @@ int ptrace_request(struct task_struct *child, long request,
 	case PTRACE_KILL:
 		if (child->exit_state)	/* already dead */
 			return 0;
-		return ptrace_resume(child, request, SIGKILL);
+		return send_sig_info(SIGKILL, SEND_SIG_NOINFO, child);
 
 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
 	case PTRACE_GETREGSET:
-- 
2.35.3