From: Ziyang Xuan william.xuanziyang@huawei.com
[ Upstream commit 69135c572d1f84261a6de2a1268513a7e71753e2 ]
After setting the sock ktls, update ctx->sk_proto to sock->sk_prot by tls_update(), so now ctx->sk_proto->close is tls_sk_proto_close(). When close the sock, tls_sk_proto_close() is called for sock->sk_prot->close is tls_sk_proto_close(). But ctx->sk_proto->close() will be executed later in tls_sk_proto_close(). Thus tls_sk_proto_close() executed repeatedly occurred. That will trigger the following bug.
================================================================= KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:tls_sk_proto_close+0xd8/0xaf0 net/tls/tls_main.c:306 Call Trace: <TASK> tls_sk_proto_close+0x356/0xaf0 net/tls/tls_main.c:329 inet_release+0x12e/0x280 net/ipv4/af_inet.c:428 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x18/0x20 net/socket.c:1365
Updating a proto which is same with sock->sk_prot is incorrect. Add proto and sock->sk_prot equality check at the head of tls_update() to fix it.
Fixes: 95fa145479fb ("bpf: sockmap/tls, close can race with map free") Reported-by: syzbot+29c3c12f3214b85ad081@syzkaller.appspotmail.com Signed-off-by: Ziyang Xuan william.xuanziyang@huawei.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/tls/tls_main.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index 7aba4ee77aba..df9177d96f7f 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -803,6 +803,9 @@ static void tls_update(struct sock *sk, struct proto *p, { struct tls_context *ctx;
+ if (sk->sk_prot == p) + return; + ctx = tls_get_ctx(sk); if (likely(ctx)) { ctx->sk_write_space = write_space;