From 04619855d9ce0725bc78a02d4d5eaa7f8c093b2a Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Tue, 18 Sep 2018 16:10:47 +0300 Subject: [PATCH] intel_th: Fix device removal logic BugLink: https://bugs.launchpad.net/bugs/1836287 commit 8801922cd94c918e4dc3a108ecaa500c4d40583f upstream. Commit a753bfcfdb1f ("intel_th: Make the switch allocate its subdevices") brings in new subdevice addition/removal logic that's broken for "host mode": the SWITCH device has no children to begin with, which is not handled in the code. This results in a null dereference bug later down the path. This patch fixes the subdevice removal code to handle host mode correctly. Signed-off-by: Alexander Shishkin Fixes: a753bfcfdb1f ("intel_th: Make the switch allocate its subdevices") CC: stable@vger.kernel.org # v4.14+ Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa Signed-off-by: Khalid Elmously --- drivers/hwtracing/intel_th/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c index c1793313bb08..757801d27604 100644 --- a/drivers/hwtracing/intel_th/core.c +++ b/drivers/hwtracing/intel_th/core.c @@ -147,7 +147,8 @@ static int intel_th_remove(struct device *dev) th->thdev[i] = NULL; } - th->num_thdevs = lowest; + if (lowest >= 0) + th->num_thdevs = lowest; } if (thdrv->attr_group) -- 2.39.5