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

Eric W. Biederman
2022-04-29T21:48:31Z

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@vger.kernel.org
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
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