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author | Xiaoming Ni <nixiaoming@huawei.com> | 2021-03-25 11:51:13 +0800 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2021-03-25 17:02:01 -0700 |
commit | 4b5db93e7f2afbdfe3b78e37879a85290187e6f1 (patch) | |
tree | 2be8fea7f9a3038986c1d018655b23abf4e9a225 | |
parent | 7574fcdbdcb335763b6b322f6928dc0fd5730451 (diff) | |
download | linux-4b5db93e7f2afbdfe3b78e37879a85290187e6f1.tar.bz2 |
nfc: Avoid endless loops caused by repeated llcp_sock_connect()
When sock_wait_state() returns -EINPROGRESS, "sk->sk_state" is
LLCP_CONNECTING. In this case, llcp_sock_connect() is repeatedly invoked,
nfc_llcp_sock_link() will add sk to local->connecting_sockets twice.
sk->sk_node->next will point to itself, that will make an endless loop
and hang-up the system.
To fix it, check whether sk->sk_state is LLCP_CONNECTING in
llcp_sock_connect() to avoid repeated invoking.
Fixes: b4011239a08e ("NFC: llcp: Fix non blocking sockets connections")
Reported-by: "kiyin(尹亮)" <kiyin@tencent.com>
Link: https://www.openwall.com/lists/oss-security/2020/11/01/1
Cc: <stable@vger.kernel.org> #v3.11
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | net/nfc/llcp_sock.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index 59172614b249..a3b46f888803 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -673,6 +673,10 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, ret = -EISCONN; goto error; } + if (sk->sk_state == LLCP_CONNECTING) { + ret = -EINPROGRESS; + goto error; + } dev = nfc_get_device(addr->dev_idx); if (dev == NULL) { |