From: "Yichun Zhang (agentzh)" <yichun@openresty.com>
To: linux-fsdevel@vger.kernel.org
Cc: "Yichun Zhang (agentzh)" <yichun@openresty.com>,
Colin Ian King <colin.i.king@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Jens Axboe <axboe@kernel.dk>,
linux-kernel@vger.kernel.org
Subject: [PATCH] relay: replay_file_open(): NULL ptr deref in CPU hotplugs
Date: Thu, 8 Sep 2022 14:17:30 -0700 [thread overview]
Message-ID: <20220908211731.11534-1-yichun@openresty.com> (raw)
CPU hotplug may introduce race conditions. We reproduced kernel panics
due to this NULL ptr deref error when doing frequent random CPU hotplugs
in a KVM guest.
Signed-off-by: Yichun Zhang (agentzh) <yichun@openresty.com>
---
kernel/relay.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/relay.c b/kernel/relay.c
index 6a611e779e95..2db69fd527d1 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -816,6 +816,9 @@ EXPORT_SYMBOL_GPL(relay_flush);
static int relay_file_open(struct inode *inode, struct file *filp)
{
struct rchan_buf *buf = inode->i_private;
+ if (unlikely(buf == NULL))
+ return -ENOENT;
+
kref_get(&buf->kref);
filp->private_data = buf;
--
2.17.2
next reply other threads:[~2022-09-08 21:17 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-08 21:17 Yichun Zhang (agentzh) [this message]
2022-09-08 21:19 ` Jens Axboe
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