4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit c9e4576743eeda8d24dedc164d65b78877f9a98c ]
When sock recvbuff is set by bpf_setsockopt(), the value must by limited by rmem_max. It is the same with sendbuff.
Fixes: 8c4b4c7e9ff0 ("bpf: Add setsockopt helper function to bpf") Signed-off-by: Yafang Shao laoar.shao@gmail.com Acked-by: Martin KaFai Lau kafai@fb.com Acked-by: Lawrence Brakmo brakmo@fb.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net 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 16350f8c8815..821050957aca 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3927,10 +3927,12 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, /* Only some socketops are supported */ switch (optname) { case SO_RCVBUF: + val = min_t(u32, val, sysctl_rmem_max); sk->sk_userlocks |= SOCK_RCVBUF_LOCK; sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF); break; case SO_SNDBUF: + val = min_t(u32, val, sysctl_wmem_max); sk->sk_userlocks |= SOCK_SNDBUF_LOCK; sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF); break;