From 08275e59a75047ba8fc0b9853bfdfc88a124763d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 17 Apr 2025 11:09:33 -0400 Subject: [PATCH] ftrace: Reinitialize hash to EMPTY_HASH after freeing There's several locations that free a ftrace hash pointer but may be referenced again. Reset them to EMPTY_HASH so that a u-a-f bug doesn't happen. Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20250417110933.20ab718b@gandalf.local.home Fixes: 0ae6b8ce200d ("ftrace: Fix accounting of subop hashes") Signed-off-by: Steven Rostedt (Google) --- kernel/trace/ftrace.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 43394445390c..d0e4a902bb40 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1297,6 +1297,8 @@ void ftrace_free_filter(struct ftrace_ops *ops) return; free_ftrace_hash(ops->func_hash->filter_hash); free_ftrace_hash(ops->func_hash->notrace_hash); + ops->func_hash->filter_hash = EMPTY_HASH; + ops->func_hash->notrace_hash = EMPTY_HASH; } EXPORT_SYMBOL_GPL(ftrace_free_filter); @@ -3443,6 +3445,7 @@ static int add_next_hash(struct ftrace_hash **filter_hash, struct ftrace_hash ** size_bits); if (ret < 0) { free_ftrace_hash(*filter_hash); + *filter_hash = EMPTY_HASH; return ret; } } @@ -3472,6 +3475,7 @@ static int add_next_hash(struct ftrace_hash **filter_hash, struct ftrace_hash ** subops_hash->notrace_hash); if (ret < 0) { free_ftrace_hash(*notrace_hash); + *notrace_hash = EMPTY_HASH; return ret; } } -- 2.49.0