From: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
To: rostedt@goodmis.org
Cc: mingo@redhat.com, linux-kernel@vger.kernel.org,
Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Subject: [PATCH] ftrace: Check if pages were allocated before calling free_pages()
Date: Tue, 6 Apr 2021 14:51:45 +0800 [thread overview]
Message-ID: <1617691905-8016-1-git-send-email-jiapeng.chong@linux.alibaba.com> (raw)
It is possible that on error pg->size can be zero when getting its
order,which would return a -1 value. It is dangerous to pass in an
order of -1 to free_pages(). Check if order is greater than or equal
to zero before calling free_pages().
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
---
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 b7e29db..74efc33 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6811,7 +6811,8 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
if (!pg->index) {
*last_pg = pg->next;
order = get_count_order(pg->size / ENTRIES_PER_PAGE);
- free_pages((unsigned long)pg->records, order);
+ if (order >= 0)
+ free_pages((unsigned long)pg->records, order);
ftrace_number_of_pages -= 1 << order;
ftrace_number_of_groups--;
kfree(pg);
--
1.8.3.1
next reply other threads:[~2021-04-06 6:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-06 6:51 Jiapeng Chong [this message]
2021-04-06 12:27 ` [PATCH] ftrace: Check if pages were allocated before calling free_pages() Steven Rostedt
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