Re: [PATCH v4.19.y] stm class: Prevent division by zero

On Wed, Mar 20, 2019 at 10:09:44AM +0200, Alexander Shishkin wrote:

commit bf7cbaae0831252b416f375ca9b1027ecd4642dd upstream.

Using STP_POLICY_ID_SET ioctl command with dummy_stm device, or any STM device that supplies zero mmio channel size, will trigger a division by zero bug in the kernel.

Prevent this by disallowing channel widths other than 1 for such devices.

Signed-off-by: Alexander Shishkin alexander.shishkin@linux.intel.com Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices")

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drivers/hwtracing/stm/core.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)

Thanks for all of the backports, now queued up.

greg k-h