From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>,
Marcel Holtmann <marcel@holtmann.org>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org, linux-bluetooth@vger.kernel.org
Subject: [PATCH AUTOSEL 5.13 171/189] Bluetooth: cmtp: fix file refcount when cmtp_attach_device fails
Date: Tue, 6 Jul 2021 07:13:51 -0400 [thread overview]
Message-ID: <20210706111409.2058071-171-sashal@kernel.org> (raw)
In-Reply-To: <20210706111409.2058071-1-sashal@kernel.org>
From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
[ Upstream commit 3cfdf8fcaafa62a4123f92eb0f4a72650da3a479 ]
When cmtp_attach_device fails, cmtp_add_connection returns the error value
which leads to the caller to doing fput through sockfd_put. But
cmtp_session kthread, which is stopped in this path will also call fput,
leading to a potential refcount underflow or a use-after-free.
Add a refcount before we signal the kthread to stop. The kthread will try
to grab the cmtp_session_sem mutex before doing the fput, which is held
when get_file is called, so there should be no races there.
Reported-by: Ryota Shiga
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/bluetooth/cmtp/core.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/bluetooth/cmtp/core.c b/net/bluetooth/cmtp/core.c
index 07cfa3249f83..0a2d78e811cf 100644
--- a/net/bluetooth/cmtp/core.c
+++ b/net/bluetooth/cmtp/core.c
@@ -392,6 +392,11 @@ int cmtp_add_connection(struct cmtp_connadd_req *req, struct socket *sock)
if (!(session->flags & BIT(CMTP_LOOPBACK))) {
err = cmtp_attach_device(session);
if (err < 0) {
+ /* Caller will call fput in case of failure, and so
+ * will cmtp_session kthread.
+ */
+ get_file(session->sock->file);
+
atomic_inc(&session->terminate);
wake_up_interruptible(sk_sleep(session->sock->sk));
up_write(&cmtp_session_sem);
--
2.30.2
next prev parent reply other threads:[~2021-07-06 11:25 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210706111409.2058071-1-sashal@kernel.org>
2021-07-06 11:13 ` [PATCH AUTOSEL 5.13 170/189] Bluetooth: btusb: Fixed too many in-token issue for Mediatek Chip Sasha Levin
2021-07-06 11:13 ` Sasha Levin [this message]
2021-07-06 11:13 ` [PATCH AUTOSEL 5.13 172/189] Bluetooth: Fix the HCI to MGMT status conversion table Sasha Levin
2021-07-06 11:13 ` [PATCH AUTOSEL 5.13 173/189] Bluetooth: Fix alt settings for incoming SCO with transparent coding format Sasha Levin
2021-07-06 11:13 ` [PATCH AUTOSEL 5.13 174/189] Bluetooth: Shutdown controller after workqueues are flushed or cancelled Sasha Levin
2021-07-06 11:13 ` [PATCH AUTOSEL 5.13 175/189] Bluetooth: btusb: Add a new QCA_ROME device (0cf3:e500) Sasha Levin
2021-07-06 11:13 ` [PATCH AUTOSEL 5.13 176/189] Bluetooth: L2CAP: Fix invalid access if ECRED Reconfigure fails Sasha Levin
2021-07-06 11:13 ` [PATCH AUTOSEL 5.13 177/189] Bluetooth: L2CAP: Fix invalid access on ECRED Connection response Sasha Levin
2021-07-06 11:13 ` [PATCH AUTOSEL 5.13 178/189] Bluetooth: btusb: Add support USB ALT 3 for WBS Sasha Levin
2021-07-06 11:13 ` [PATCH AUTOSEL 5.13 179/189] Bluetooth: mgmt: Fix the command returns garbage parameter value Sasha Levin
2021-07-06 11:14 ` [PATCH AUTOSEL 5.13 180/189] Bluetooth: btusb: use default nvm if boardID is 0 for wcn6855 Sasha Levin
2021-07-06 11:14 ` [PATCH AUTOSEL 5.13 181/189] Bluetooth: btusb: fix bt fiwmare downloading failure issue for qca btsoc Sasha Levin
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