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authorRui Miguel Silva <rmfrfs@gmail.com>2017-01-23 16:32:57 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-25 11:36:59 +0100
commitb17c1bba9cec1727451b906d9a0c209774624873 (patch)
treef0a0f51d405c884e23f695695858d85f6260fec0
parent9579c4dc21292f375715d7acca439dac9855b3e9 (diff)
downloadlinux-b17c1bba9cec1727451b906d9a0c209774624873.tar.bz2
staging: greybus: timesync: validate platform state callback
When tearingdown timesync, and not in arche platform, the state platform callback is not initialized. That will trigger the following NULL dereferencing. CallTrace: ? gb_timesync_platform_unlock_bus+0x11/0x20 [greybus] gb_timesync_teardown+0x85/0xc0 [greybus] gb_timesync_svc_remove+0xab/0x190 [greybus] gb_svc_del+0x29/0x110 [greybus] gb_hd_del+0x14/0x20 [greybus] ap_disconnect+0x24/0x60 [gb_es2] usb_unbind_interface+0x7a/0x2c0 __device_release_driver+0x96/0x150 device_release_driver+0x1e/0x30 bus_remove_device+0xe7/0x130 device_del+0x116/0x230 usb_disable_device+0x97/0x1f0 usb_disconnect+0x80/0x260 hub_event+0x5ca/0x10e0 process_one_work+0x126/0x3b0 worker_thread+0x55/0x4c0 ? process_one_work+0x3b0/0x3b0 kthread+0xc4/0xe0 ? kthread_park+0xb0/0xb0 ret_from_fork+0x22/0x30 So, fix that by adding checks before use the callback. Fixes: 970dc85bd95d ("greybus: timesync: Add timesync core driver") Cc: <stable@vger.kernel.org> # 4.9.x Signed-off-by: Rui Miguel Silva <rmfrfs@gmail.com> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/staging/greybus/timesync_platform.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/staging/greybus/timesync_platform.c b/drivers/staging/greybus/timesync_platform.c
index 113f3d6c4b3a..27f75b17679b 100644
--- a/drivers/staging/greybus/timesync_platform.c
+++ b/drivers/staging/greybus/timesync_platform.c
@@ -45,12 +45,18 @@ u32 gb_timesync_platform_get_clock_rate(void)
int gb_timesync_platform_lock_bus(struct gb_timesync_svc *pdata)
{
+ if (!arche_platform_change_state_cb)
+ return 0;
+
return arche_platform_change_state_cb(ARCHE_PLATFORM_STATE_TIME_SYNC,
pdata);
}
void gb_timesync_platform_unlock_bus(void)
{
+ if (!arche_platform_change_state_cb)
+ return;
+
arche_platform_change_state_cb(ARCHE_PLATFORM_STATE_ACTIVE, NULL);
}