[PATCH 8/9] bpf: Check address length before reading address family

[Tetsuo Handa]

KMSAN will complain if valid address length passed to bpf_bind() is
shorter than sizeof("struct sockaddr"->sa_family) bytes.

Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
---
 net/core/filter.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 41f633cf4fc1..b9089fda4367 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4458,6 +4458,8 @@ BPF_CALL_3(bpf_bind, struct bpf_sock_addr_kern *, ctx, 
struct sockaddr *, addr,
         * Only binding to IP is supported.
         */
        err = -EINVAL;
+       if (addr_len < offsetofend(struct sockaddr, sa_family))
+               return err;
        if (addr->sa_family == AF_INET) {
                if (addr_len < sizeof(struct sockaddr_in))
                        return err;
-- 
2.16.5