Re: [BUG] char: pcmcia: a possible concurrency double-free bug in rx_alloc_buffers()

[Greg KH]

On Mon, Jan 07, 2019 at 04:12:22PM +0800, Jia-Ju Bai wrote:
> In drivers/char/pcmcia/synclink_cs.c, the functions mgslpc_open() and hdlcdev_open() can be concurrently executed.
> 
> hdlcdev_open
>   startup
>     claim_resources
>       rx_alloc_buffers
>         line 2641: kfree(info->rx_buf)
> 
> mgslpc_open
>   startup
>     claim_resources
>       rx_alloc_buffers
>         line 2641: kfree(info->rx_buf)
> 
> Thus, a possible concurrency double-free bug may occur.
> 
> This possible bug is found by a static analysis tool written by myself and my manual code review.

Care to send a patch to fix up this potential issue?

thanks,

greg k-h