[PATCH 5.4 102/320] bpf: Fix SO_RCVBUF/SO_SNDBUF handling in _bpf_setsockopt().

Greg Kroah-Hartman
2022-01-24T20:10:44Z

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