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authorPeter Hurley <peter@hurleysoftware.com>2014-02-10 02:59:06 +0100
committerMarcel Holtmann <marcel@holtmann.org>2014-02-14 22:39:29 +0100
commit960603a54aa0d5f4f1c4f1037bcaee571d03cb1e (patch)
treee226fbc1a87886de9b8fdc821d6f39a4d67ee40a /net/bluetooth/rfcomm/tty.c
parentBluetooth: Fix racy acquire of rfcomm_dev reference (diff)
downloadlinux-960603a54aa0d5f4f1c4f1037bcaee571d03cb1e.tar.xz
linux-960603a54aa0d5f4f1c4f1037bcaee571d03cb1e.zip
Bluetooth: Exclude released devices from RFCOMMGETDEVLIST ioctl
When enumerating RFCOMM devices in the rfcomm_dev_list, holding the rfcomm_dev_lock only guarantees the existence of the enumerated rfcomm_dev in memory, and not safe access to its state. Testing the device state (such as RFCOMM_TTY_RELEASED) does not guarantee the device will remain in that state for the subsequent access to the rfcomm_dev's fields, nor guarantee that teardown has not commenced. Obtain an rfcomm_dev reference for the duration of rfcomm_dev access. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Tested-By: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth/rfcomm/tty.c')
-rw-r--r--net/bluetooth/rfcomm/tty.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index 7cf193f0eea7..b385d9985656 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -468,7 +468,7 @@ static int rfcomm_get_dev_list(void __user *arg)
spin_lock(&rfcomm_dev_lock);
list_for_each_entry(dev, &rfcomm_dev_list, list) {
- if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
+ if (!tty_port_get(&dev->port))
continue;
(di + n)->id = dev->id;
(di + n)->flags = dev->flags;
@@ -476,6 +476,7 @@ static int rfcomm_get_dev_list(void __user *arg)
(di + n)->channel = dev->channel;
bacpy(&(di + n)->src, &dev->src);
bacpy(&(di + n)->dst, &dev->dst);
+ tty_port_put(&dev->port);
if (++n >= dev_num)
break;
}