diff options
| author | Alex Williamson <alex.williamson@redhat.com> | 2014-10-31 18:13:07 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-07 20:17:27 +0100 |
| commit | 0372ffb35d00288802265586a29c117911d02fb8 (patch) | |
| tree | e701ab8f25cdd801ecaf3f1c303c18df83f78e49 /drivers | |
| parent | driver core: fix race with userland in device_add() (diff) | |
| download | linux-0372ffb35d00288802265586a29c117911d02fb8.tar.xz linux-0372ffb35d00288802265586a29c117911d02fb8.zip | |
driver core: Fix unbalanced device reference in drivers_probe
bus_find_device_by_name() acquires a device reference which is never
released. This results in an object leak, which on older kernels
results in failure to release all resources of PCI devices. libvirt
uses drivers_probe to re-attach devices to the host after assignment
and is therefore a common trigger for this leak.
Example:
# cd /sys/bus/pci/
# dmesg -C
# echo 1 > devices/0000\:01\:00.0/sriov_numvfs
# echo 0 > devices/0000\:01\:00.0/sriov_numvfs
# dmesg | grep 01:10
pci 0000:01:10.0: [8086:10ca] type 00 class 0x020000
kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_add_internal: parent: '0000:00:01.0', set: 'devices'
kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_uevent_env
kobject: '0000:01:10.0' (ffff8801d79cd0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0'
kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_uevent_env
kobject: '0000:01:10.0' (ffff8801d79cd0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0'
kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_uevent_env
kobject: '0000:01:10.0' (ffff8801d79cd0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0'
kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_cleanup, parent (null)
kobject: '0000:01:10.0' (ffff8801d79cd0a8): calling ktype release
kobject: '0000:01:10.0': free name
[kobject freed as expected]
# dmesg -C
# echo 1 > devices/0000\:01\:00.0/sriov_numvfs
# echo 0000:01:10.0 > drivers_probe
# echo 0 > devices/0000\:01\:00.0/sriov_numvfs
# dmesg | grep 01:10
pci 0000:01:10.0: [8086:10ca] type 00 class 0x020000
kobject: '0000:01:10.0' (ffff8801d79ce0a8): kobject_add_internal: parent: '0000:00:01.0', set: 'devices'
kobject: '0000:01:10.0' (ffff8801d79ce0a8): kobject_uevent_env
kobject: '0000:01:10.0' (ffff8801d79ce0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0'
kobject: '0000:01:10.0' (ffff8801d79ce0a8): kobject_uevent_env
kobject: '0000:01:10.0' (ffff8801d79ce0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0'
kobject: '0000:01:10.0' (ffff8801d79ce0a8): kobject_uevent_env
kobject: '0000:01:10.0' (ffff8801d79ce0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0'
[no free]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/base/bus.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 83e910a57563..876bae5ade33 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -254,13 +254,15 @@ static ssize_t store_drivers_probe(struct bus_type *bus, const char *buf, size_t count) { struct device *dev; + int err = -EINVAL; dev = bus_find_device_by_name(bus, NULL, buf); if (!dev) return -ENODEV; - if (bus_rescan_devices_helper(dev, NULL) != 0) - return -EINVAL; - return count; + if (bus_rescan_devices_helper(dev, NULL) == 0) + err = count; + put_device(dev); + return err; } static struct device *next_device(struct klist_iter *i) |