On Tue, Aug 7, 2018 at 12:18 AM, Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
> Some of fuzzers set panic_on_warn=1 so that they can handle WARN()ings
> the same way they handle full-blown kernel crashes. We used WARN() in
> input_alloc_absinfo() to get a better idea where memory allocation
> failed, but since then kmalloc() and friends started dumping call stack
> on memory allocation failures anyway, so we are not getting anything
> extra from WARN().
>
> Because of the above, let's replace WARN with dev_err(). We use dev_err()
> instead of simply removing message and relying on kcalloc() to give us
> stack dump so that we'd know the instance of hardware device to which we
> were trying to attach input device.
>
> Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> ---
> drivers/input/input.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/input/input.c b/drivers/input/input.c
> index 90453e2ab6cf..260f00ebe34d 100644
> --- a/drivers/input/input.c
> +++ b/drivers/input/input.c
> @@ -481,11 +481,19 @@ EXPORT_SYMBOL(input_inject_event);
> */
> void input_alloc_absinfo(struct input_dev *dev)
> {
> - if (!dev->absinfo)
> - dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo),
> - GFP_KERNEL);
> + if (dev->absinfo)
> + return;
>
> - WARN(!dev->absinfo, "%s(): kcalloc() failed?\n", __func__);
> + dev->absinfo = kcalloc(ABS_CNT, sizeof(*dev->absinfo), GFP_KERNEL);
> + if (!dev->absinfo) {
> + dev_err(dev->dev.parent ?: &dev->dev,
> + "%s: unable to allocate memory\n", __func__);
> + /*
> + * We will handle this allocation failure in
> + * input_register_device() when we refuse to register input
> + * device with ABS bits but without absinfo.
> + */
> + }
> }
> EXPORT_SYMBOL(input_alloc_absinfo);
Thanks!
Acked-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
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