bpf: Fix SO_RCVBUF/SO_SNDBUF handling in _bpf_setsockopt().

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

diff --git a/net/core/filter.c b/net/core/filter.c
index 606ab5a..368fe28 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4741,12 +4741,14 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname,
                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));