Return-Path: From: Peter Hurley To: Marcel Holtmann Cc: Gustavo Padovan , Johan Hedberg , Gianluca Anzolin , Alexander Holler , Andrey Vihrov , Sander Eikelenboom , linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Hurley Subject: [PATCH 18/24] Bluetooth: Serialize RFCOMMCREATEDEV and RFCOMMRELEASEDEV ioctls Date: Sun, 9 Feb 2014 20:59:18 -0500 Message-Id: <1391997564-1805-19-git-send-email-peter@hurleysoftware.com> In-Reply-To: <1391997564-1805-1-git-send-email-peter@hurleysoftware.com> References: <1391997564-1805-1-git-send-email-peter@hurleysoftware.com> List-ID: At least two different race conditions exist with multiple concurrent RFCOMMCREATEDEV and RFCOMMRELEASEDEV ioctls: * Multiple concurrent RFCOMMCREATEDEVs with RFCOMM_REUSE_DLC can mistakenly share the same DLC. * RFCOMMRELEASEDEV can destruct the rfcomm_dev still being constructed by RFCOMMCREATEDEV. Introduce rfcomm_ioctl_mutex to serialize these add/remove operations. Signed-off-by: Peter Hurley --- net/bluetooth/rfcomm/tty.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c index 4a38b54..ef27695 100644 --- a/net/bluetooth/rfcomm/tty.c +++ b/net/bluetooth/rfcomm/tty.c @@ -40,6 +40,7 @@ #define RFCOMM_TTY_MAJOR 216 /* device node major id of the usb/bluetooth.c driver */ #define RFCOMM_TTY_MINOR 0 +static DEFINE_MUTEX(rfcomm_ioctl_mutex); static struct tty_driver *rfcomm_tty_driver; struct rfcomm_dev { @@ -373,7 +374,7 @@ static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size #define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP)) -static int rfcomm_create_dev(struct sock *sk, void __user *arg) +static int __rfcomm_create_dev(struct sock *sk, void __user *arg) { struct rfcomm_dev_req req; struct rfcomm_dlc *dlc; @@ -423,7 +424,7 @@ static int rfcomm_create_dev(struct sock *sk, void __user *arg) return id; } -static int rfcomm_release_dev(void __user *arg) +static int __rfcomm_release_dev(void __user *arg) { struct rfcomm_dev_req req; struct rfcomm_dev *dev; @@ -466,6 +467,28 @@ static int rfcomm_release_dev(void __user *arg) return 0; } +static int rfcomm_create_dev(struct sock *sk, void __user *arg) +{ + int ret; + + mutex_lock(&rfcomm_ioctl_mutex); + ret = __rfcomm_create_dev(sk, arg); + mutex_unlock(&rfcomm_ioctl_mutex); + + return ret; +} + +static int rfcomm_release_dev(void __user *arg) +{ + int ret; + + mutex_lock(&rfcomm_ioctl_mutex); + ret = __rfcomm_release_dev(arg); + mutex_unlock(&rfcomm_ioctl_mutex); + + return ret; +} + static int rfcomm_get_dev_list(void __user *arg) { struct rfcomm_dev *dev; -- 1.8.1.2