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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Kuniyuki Iwashima <kuniyu@amazon.co.jp>,
        Alexei Starovoitov <ast@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 102/320] bpf: Fix SO_RCVBUF/SO_SNDBUF handling in _bpf_setsockopt().
Date:   Mon, 24 Jan 2022 19:41:26 +0100
Message-Id: <20220124183957.191563339@linuxfoundation.org>
In-Reply-To: <20220124183953.750177707@linuxfoundation.org>
References: <20220124183953.750177707@linuxfoundation.org>
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From: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

[ Upstream commit 04c350b1ae6bdb12b84009a4d0bf5ab4e621c47b ]

The commit 4057765f2dee ("sock: consistent handling of extreme
SO_SNDBUF/SO_RCVBUF values") added a change to prevent underflow
in setsockopt() around SO_SNDBUF/SO_RCVBUF.

This patch adds the same change to _bpf_setsockopt().

Fixes: 4057765f2dee ("sock: consistent handling of extreme SO_SNDBUF/SO_RCVBUF values")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220104013153.97906-2-kuniyu@amazon.co.jp
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/core/filter.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 5ebc973ed4c50..b90c0b5a10112 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4248,12 +4248,14 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock,
 		switch (optname) {
 		case SO_RCVBUF:
 			val = min_t(u32, val, sysctl_rmem_max);
+			val = min_t(int, val, INT_MAX / 2);
 			sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
 			WRITE_ONCE(sk->sk_rcvbuf,
 				   max_t(int, val * 2, SOCK_MIN_RCVBUF));
 			break;
 		case SO_SNDBUF:
 			val = min_t(u32, val, sysctl_wmem_max);
+			val = min_t(int, val, INT_MAX / 2);
 			sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
 			WRITE_ONCE(sk->sk_sndbuf,
 				   max_t(int, val * 2, SOCK_MIN_SNDBUF));
-- 
2.34.1