From: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
[ 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@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 7b2b0e7ffee4..fc60bef83f90 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -873,6 +873,9 @@ 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;
--
2.35.1
