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From: Pengcheng Yang <yangpc@wangsu.com>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>, Song Liu <song@kernel.org>,
	Yonghong Song <yhs@fb.com>
Cc: Lawrence Brakmo <brakmo@fb.com>,
	bpf@vger.kernel.org, Pengcheng Yang <yangpc@wangsu.com>
Subject: [PATCH bpf] samples/bpf: Fix buffer overflow in tcp_basertt
Date: Fri,  5 May 2023 16:50:58 +0800	[thread overview]
Message-ID: <1683276658-2860-1-git-send-email-yangpc@wangsu.com> (raw)

Using sizeof(nv) or strlen(nv)+1 is correct.

Fixes: c890063e4404 ("bpf: sample BPF_SOCKET_OPS_BASE_RTT program")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
---
 samples/bpf/tcp_basertt_kern.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/samples/bpf/tcp_basertt_kern.c b/samples/bpf/tcp_basertt_kern.c
index 8dfe09a92fec..822b0742b815 100644
--- a/samples/bpf/tcp_basertt_kern.c
+++ b/samples/bpf/tcp_basertt_kern.c
@@ -47,7 +47,7 @@ int bpf_basertt(struct bpf_sock_ops *skops)
 		case BPF_SOCK_OPS_BASE_RTT:
 			n = bpf_getsockopt(skops, SOL_TCP, TCP_CONGESTION,
 					   cong, sizeof(cong));
-			if (!n && !__builtin_memcmp(cong, nv, sizeof(nv)+1)) {
+			if (!n && !__builtin_memcmp(cong, nv, sizeof(nv))) {
 				/* Set base_rtt to 80us */
 				rv = 80;
 			} else if (n) {
-- 
2.38.1


             reply	other threads:[~2023-05-05  8:51 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-05  8:50 Pengcheng Yang [this message]
2023-05-05 15:40 ` [PATCH bpf] samples/bpf: Fix buffer overflow in tcp_basertt patchwork-bot+netdevbpf

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