Re: [PATCH] Check sk before sendpage

[Lee Duncan]

On 7/10/19 12:30 AM, Yang Bin wrote:

> From: " Yang Bin "<yang.bin18@xxxxxxxxxx>
>
> Before xmit,iscsi may disconnect just now.
> So must check connection sock NULL or not,or kernel will crash for
> accessing NULL pointer.
>
> Signed-off-by: Yang Bin <yang.bin18@xxxxxxxxxx>
> ---
>  drivers/scsi/iscsi_tcp.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
> index 7bedbe8..a59c49f 100644
> --- a/drivers/scsi/iscsi_tcp.c
> +++ b/drivers/scsi/iscsi_tcp.c
> @@ -264,6 +264,9 @@ static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
>  	unsigned int copied = 0;
>  	int r = 0;
>  
> +	if (!sk)
> +		return -ENOTCONN;
> +
>  	while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
>  		struct scatterlist *sg;
>  		unsigned int offset, copy;
>

If the socket can be closed right before iscsi_sw_tcp_xmit_segment() is
called, can it be called in the middle of sending segments? (In which
case the check would have to be in the while loop.)

-- 

Lee Duncan