From 4fdd88877e5259dcc5e504dca449acc0324d71b9 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 26 Mar 2020 23:49:36 +0900 Subject: [PATCH] kprobes: Lock kprobe_mutex while showing kprobe_blacklist Lock kprobe_mutex while showing kprobe_blacklist to prevent updating the kprobe_blacklist. Signed-off-by: Masami Hiramatsu Signed-off-by: Thomas Gleixner Reviewed-by: Alexandre Chartre Acked-by: Peter Zijlstra Link: https://lkml.kernel.org/r/20200505134059.571125195@linutronix.de --- kernel/kprobes.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 2625c241ac00..570d60827656 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2420,6 +2420,7 @@ static const struct file_operations debugfs_kprobes_operations = { /* kprobes/blacklist -- shows which functions can not be probed */ static void *kprobe_blacklist_seq_start(struct seq_file *m, loff_t *pos) { + mutex_lock(&kprobe_mutex); return seq_list_start(&kprobe_blacklist, *pos); } @@ -2446,10 +2447,15 @@ static int kprobe_blacklist_seq_show(struct seq_file *m, void *v) return 0; } +static void kprobe_blacklist_seq_stop(struct seq_file *f, void *v) +{ + mutex_unlock(&kprobe_mutex); +} + static const struct seq_operations kprobe_blacklist_seq_ops = { .start = kprobe_blacklist_seq_start, .next = kprobe_blacklist_seq_next, - .stop = kprobe_seq_stop, /* Reuse void function */ + .stop = kprobe_blacklist_seq_stop, .show = kprobe_blacklist_seq_show, };