* [bug report] bpf, sockmap: convert to generic sk_msg interface
@ 2019-10-14 12:13 Dan Carpenter
2019-10-14 16:46 ` Martin Lau
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2019-10-14 12:13 UTC (permalink / raw)
To: daniel; +Cc: bpf
Hello Daniel Borkmann,
This is a semi-automatic email about new static checker warnings.
The patch 604326b41a6f: "bpf, sockmap: convert to generic sk_msg
interface" from Oct 13, 2018, leads to the following Smatch complaint:
net/core/skmsg.c:792 sk_psock_write_space()
error: we previously assumed 'psock' could be null (see line 790)
net/core/skmsg.c
789 psock = sk_psock(sk);
790 if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)))
^^^^^
Check for NULL
791 schedule_work(&psock->work);
792 write_space = psock->saved_write_space;
^^^^^^^^^^^^^^^^^^^^^^^^
793 rcu_read_unlock();
794 write_space(sk);
^^^^^^^^^^^^^^
The warning is on the wrong line. The dereference is really here.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [bug report] bpf, sockmap: convert to generic sk_msg interface
2019-10-14 12:13 [bug report] bpf, sockmap: convert to generic sk_msg interface Dan Carpenter
@ 2019-10-14 16:46 ` Martin Lau
2019-10-14 16:53 ` John Fastabend
0 siblings, 1 reply; 3+ messages in thread
From: Martin Lau @ 2019-10-14 16:46 UTC (permalink / raw)
To: John Fastabend; +Cc: daniel@iogearbox.net, bpf@vger.kernel.org, Dan Carpenter
On Mon, Oct 14, 2019 at 03:13:30PM +0300, Dan Carpenter wrote:
> Hello Daniel Borkmann,
>
> This is a semi-automatic email about new static checker warnings.
>
> The patch 604326b41a6f: "bpf, sockmap: convert to generic sk_msg
> interface" from Oct 13, 2018, leads to the following Smatch complaint:
>
> net/core/skmsg.c:792 sk_psock_write_space()
> error: we previously assumed 'psock' could be null (see line 790)
>
> net/core/skmsg.c
> 789 psock = sk_psock(sk);
> 790 if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)))
> ^^^^^
> Check for NULL
>
> 791 schedule_work(&psock->work);
> 792 write_space = psock->saved_write_space;
> ^^^^^^^^^^^^^^^^^^^^^^^^
>
> 793 rcu_read_unlock();
> 794 write_space(sk);
> ^^^^^^^^^^^^^^
> The warning is on the wrong line. The dereference is really here.
>
> regards,
> dan carpenter
John, can you also take a look?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [bug report] bpf, sockmap: convert to generic sk_msg interface
2019-10-14 16:46 ` Martin Lau
@ 2019-10-14 16:53 ` John Fastabend
0 siblings, 0 replies; 3+ messages in thread
From: John Fastabend @ 2019-10-14 16:53 UTC (permalink / raw)
To: Martin Lau, John Fastabend
Cc: daniel@iogearbox.net, bpf@vger.kernel.org, Dan Carpenter
Martin Lau wrote:
> On Mon, Oct 14, 2019 at 03:13:30PM +0300, Dan Carpenter wrote:
> > Hello Daniel Borkmann,
> >
> > This is a semi-automatic email about new static checker warnings.
> >
> > The patch 604326b41a6f: "bpf, sockmap: convert to generic sk_msg
> > interface" from Oct 13, 2018, leads to the following Smatch complaint:
> >
> > net/core/skmsg.c:792 sk_psock_write_space()
> > error: we previously assumed 'psock' could be null (see line 790)
> >
> > net/core/skmsg.c
> > 789 psock = sk_psock(sk);
> > 790 if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)))
> > ^^^^^
> > Check for NULL
> >
> > 791 schedule_work(&psock->work);
> > 792 write_space = psock->saved_write_space;
> > ^^^^^^^^^^^^^^^^^^^^^^^^
> >
> > 793 rcu_read_unlock();
> > 794 write_space(sk);
> > ^^^^^^^^^^^^^^
> > The warning is on the wrong line. The dereference is really here.
> >
> > regards,
> > dan carpenter
> John, can you also take a look?
Thanks Dan, seems there is a chance we could have a null psock here
so we need to wrap both dereferences in the 'if (psock)'. I'll send
a patch.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-10-14 16:53 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-10-14 12:13 [bug report] bpf, sockmap: convert to generic sk_msg interface Dan Carpenter
2019-10-14 16:46 ` Martin Lau
2019-10-14 16:53 ` John Fastabend
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox