From: Xin Liu <liuxin350@huawei.com>
To: <daniel@iogearbox.net>
Cc: <andrii@kernel.org>, <ast@kernel.org>, <bpf@vger.kernel.org>,
<davem@davemloft.net>, <edumazet@google.com>, <hsinweih@uci.edu>,
<jakub@cloudflare.com>, <john.fastabend@gmail.com>,
<kuba@kernel.org>, <linux-kernel@vger.kernel.org>,
<liuxin350@huawei.com>, <netdev@vger.kernel.org>,
<pabeni@redhat.com>,
<syzbot+49f6cef45247ff249498@syzkaller.appspotmail.com>,
<syzkaller-bugs@googlegroups.com>, <yanan@huawei.com>,
<wuchangye@huawei.com>, <xiesongyang@huawei.com>,
<kongweibin2@huawei.com>, <zhangmingyi5@huawei.com>
Subject: [PATCH] libbpf:fix use empty function pointers in ringbuf_poll
Date: Mon, 5 Jun 2023 11:34:49 +0800 [thread overview]
Message-ID: <20230605033449.239123-1-liuxin350@huawei.com> (raw)
From: zhangmingyi <zhangmingyi5@huawei.com>
The sample_cb of the ring_buffer__new interface can transfer NULL. However,
the system does not check whether sample_cb is NULL during
ring_buffer__poll, null pointer is used.
Signed-off-by: zhangmingyi <zhangmingyi5@huawei.com>
---
tools/lib/bpf/ringbuf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/ringbuf.c b/tools/lib/bpf/ringbuf.c
index 02199364db13..3661338a1d2e 100644
--- a/tools/lib/bpf/ringbuf.c
+++ b/tools/lib/bpf/ringbuf.c
@@ -248,7 +248,7 @@ static int64_t ringbuf_process_ring(struct ring *r)
got_new_data = true;
cons_pos += roundup_len(len);
- if ((len & BPF_RINGBUF_DISCARD_BIT) == 0) {
+ if (r->sample_cb && ((len & BPF_RINGBUF_DISCARD_BIT) == 0)) {
sample = (void *)len_ptr + BPF_RINGBUF_HDR_SZ;
err = r->sample_cb(r->ctx, sample, len);
if (err < 0) {
--
2.33.0
next reply other threads:[~2023-06-05 3:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-05 3:34 Xin Liu [this message]
2023-06-05 17:26 ` [PATCH] libbpf:fix use empty function pointers in ringbuf_poll Stanislav Fomichev
2023-06-08 12:58 ` zhangmingyi
2023-06-08 16:27 ` Stanislav Fomichev
2023-06-08 17:38 ` Andrii Nakryiko
2023-06-09 9:36 ` zhangmingyi
2023-06-09 16:55 ` Stanislav Fomichev
2023-06-09 18:23 ` Andrii Nakryiko
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