From 63444b7617c09aeed36282e061c3f80818f2b600 Mon Sep 17 00:00:00 2001 From: Leon Hwang Date: Thu, 30 Jul 2026 23:04:08 +0800 Subject: [PATCH] ftrace: Protect direct_functions in ftrace_find_rec_direct Fix accessing the __rcu pointer direct_functions with RCU protection. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260730150411.88667-2-leon.hwang@linux.dev Fixes: d05cb470663a ("ftrace: Fix modification of direct_function hash while in use") Acked-by: Jiri Olsa Suggested-by: Steven Rostedt Signed-off-by: Leon Hwang Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6c47a94f5924..c5d1d0d42ccc 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2645,7 +2645,8 @@ unsigned long ftrace_find_rec_direct(unsigned long ip) { struct ftrace_func_entry *entry; - entry = __ftrace_lookup_ip(direct_functions, ip); + guard(preempt_notrace)(); + entry = __ftrace_lookup_ip(rcu_dereference_sched(direct_functions), ip); if (!entry) return 0; -- 2.47.3