* [PATCH] Check sk before sendpage
@ 2019-07-10 7:30 Yang Bin
2019-07-10 17:47 ` Lee Duncan
0 siblings, 1 reply; 3+ messages in thread
From: Yang Bin @ 2019-07-10 7:30 UTC (permalink / raw)
To: lduncan
Cc: cleech, jejb, martin.petersen, open-iscsi, linux-scsi,
linux-kernel, xue.zhihong, wang.yi59, wang.liang82, Yang Bin
From: " Yang Bin "<yang.bin18@zte.com.cn>
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@zte.com.cn>
---
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;
--
1.8.3.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] Check sk before sendpage
2019-07-10 7:30 [PATCH] Check sk before sendpage Yang Bin
@ 2019-07-10 17:47 ` Lee Duncan
2019-07-10 18:52 ` James Bottomley
0 siblings, 1 reply; 3+ messages in thread
From: Lee Duncan @ 2019-07-10 17:47 UTC (permalink / raw)
To: Yang Bin
Cc: open-iscsi@googlegroups.com, jejb@linux.ibm.com,
martin.petersen@oracle.com, cleech@redhat.com,
linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
wang.liang82@zte.com.cn, wang.yi59@zte.com.cn,
xue.zhihong@zte.com.cn
On 7/10/19 12:30 AM, Yang Bin wrote:
> From: " Yang Bin "<yang.bin18@zte.com.cn>
>
> 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@zte.com.cn>
> ---
> 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
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] Check sk before sendpage
2019-07-10 17:47 ` Lee Duncan
@ 2019-07-10 18:52 ` James Bottomley
0 siblings, 0 replies; 3+ messages in thread
From: James Bottomley @ 2019-07-10 18:52 UTC (permalink / raw)
To: Lee Duncan, Yang Bin
Cc: open-iscsi@googlegroups.com, martin.petersen@oracle.com,
cleech@redhat.com, linux-kernel@vger.kernel.org,
linux-scsi@vger.kernel.org, wang.liang82@zte.com.cn,
wang.yi59@zte.com.cn, xue.zhihong@zte.com.cn
On Wed, 2019-07-10 at 17:47 +0000, Lee Duncan wrote:
> On 7/10/19 12:30 AM, Yang Bin wrote:
>
> > From: " Yang Bin "<yang.bin18@zte.com.cn>
> >
> > 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@zte.com.cn>
> > ---
> > 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.)
I think the important point is: is this an actual observed bug or just
a theoretical problem?
The reason for asking is this call is controlled directly by the
ISCSI_UEVENT_DESTROY_CONN event sent by the iscsi daemon. Obviously if
the daemon goes haywire and doesn't shut down the connection before
sending the destroy event, we may get the crash, but I would be
inclined to say fix the daemon.
James
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-07-10 17:47 ` Lee Duncan
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