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authorIlya Lesokhin <ilyal@mellanox.com>2018-01-16 15:31:52 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-01-31 14:03:48 +0100
commita022bbe393fbe3a1f471ee94d846be03f7fe2136 (patch)
tree3403ea14792d77dd907f0aebfeffd597e18447a1 /net/tls
parent48606bb1eef7c46f154cb4a6c5509729e60a4e91 (diff)
net/tls: Only attach to sockets in ESTABLISHED state
[ Upstream commit d91c3e17f75f218022140dee18cf515292184a8f ] Calling accept on a TCP socket with a TLS ulp attached results in two sockets that share the same ulp context. The ulp context is freed while a socket is destroyed, so after one of the sockets is released, the second second will trigger a use after free when it tries to access the ulp context attached to it. We restrict the TLS ulp to sockets in ESTABLISHED state to prevent the scenario above. Fixes: 3c4d7559159b ("tls: kernel TLS support") Reported-by: syzbot+904e7cd6c5c741609228@syzkaller.appspotmail.com Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/tls')
-rw-r--r--net/tls/tls_main.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 60aff60e30ad..70757098f79b 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -444,6 +444,15 @@ static int tls_init(struct sock *sk)
struct tls_context *ctx;
int rc = 0;
+ /* The TLS ulp is currently supported only for TCP sockets
+ * in ESTABLISHED state.
+ * Supporting sockets in LISTEN state will require us
+ * to modify the accept implementation to clone rather then
+ * share the ulp context.
+ */
+ if (sk->sk_state != TCP_ESTABLISHED)
+ return -ENOTSUPP;
+
/* allocate tls context */
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx) {