4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
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 <alexander.shishkin@xxxxxxxxxxxxxxx>
Fixes: a753bfcfdb1f ("intel_th: Make the switch allocate its subdevices")
CC: stable@xxxxxxxxxxxxxxx # v4.14+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/hwtracing/intel_th/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -139,7 +139,8 @@ static int intel_th_remove(struct device
th->thdev[i] = NULL;
}
- th->num_thdevs = lowest;
+ if (lowest >= 0)
+ th->num_thdevs = lowest;
}
if (thdrv->attr_group)
