On Tue, May 14, 2019 at 03:43:00PM +0800, YueHaibing wrote:
>
> If ppp_deflate fails to register in deflate_init,
> module initialization failed out, however
> ppp_deflate_draft may has been regiestred and not
> unregistered before return.
> Then the seconed modprobe will trigger crash like this.
>
> Reported-by: Hulk Robot <hul...@huawei.com>
> Signed-off-by: YueHaibing <yuehaib...@huawei.com>
> ---
> drivers/net/ppp/ppp_deflate.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/ppp/ppp_deflate.c b/drivers/net/ppp/ppp_deflate.c
> index b5edc7f..2829efe 100644
> --- a/drivers/net/ppp/ppp_deflate.c
> +++ b/drivers/net/ppp/ppp_deflate.c
> @@ -610,12 +610,16 @@ static void z_incomp(void *arg, unsigned char *ibuf,
> int icnt)
>
> static int __init deflate_init(void)
> {
> - int answer = ppp_register_compressor(&ppp_deflate);
> - if (answer == 0)
> - printk(KERN_INFO
> - "PPP Deflate Compression module registered\n");
> + int answer;
> +
> + answer = ppp_register_compressor(&ppp_deflate);
> + if (answer)
> + return answer;
> +
> + pr_info("PPP Deflate Compression module registered\n");
> ppp_register_compressor(&ppp_deflate_draft);
> - return answer;
> +
> + return 0;
> }
>
I'd be cleaner to also check for ppp_deflate_draft registration failure
IMHO (and print the log line only if both compressors get registered
successfully).
