On Mon, 09 Oct 2017 04:13:16 +0200,
Jia-Ju Bai wrote:
>
> The riptide driver may sleep under a spinlock, and the function call path is:
> snd_riptide_prepare (acquire the spinlock)
> setsampleformat
> sendcmd
> riptide_reset
> try_to_load_firmware
> request_firmware
> _request_firmware (drivers/base/firmware_class.c)
> _request_firmware_prepare
> kzalloc(GFP_KERNEL) --> may sleep
>
> To fix it, GFP_KERNEL is replaced with GFP_ATOMIC in _request_firmware_prepare.
> This bug is found by my static analysis tool and my code review.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxx>
This doesn't happen. try_to_load_firmware() aborts before the
request_firmware() call when chip == NULL, which is the case from
sendcmd().
And, moreover, the call of request_firmware() itself inside the
spinlock would be already buggy.
thanks,
Takashi
> ---
> drivers/base/firmware_class.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
> index 4b57cf5..d89f676 100644
> --- a/drivers/base/firmware_class.c
> +++ b/drivers/base/firmware_class.c
> @@ -1138,7 +1138,7 @@ static inline void kill_pending_fw_fallback_reqs(bool only_kill_custom) { }
> struct firmware_buf *buf;
> int ret;
>
> - *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
> + *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_ATOMIC);
> if (!firmware) {
> dev_err(device, "%s: kmalloc(struct firmware) failed\n",
> __func__);
> --
> 1.7.9.5
>
>
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