From: Khalid Masum <khalid.masum.92@gmail.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
Steffen Klassert <steffen.klassert@secunet.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
linux-kernel-mentees
<linux-kernel-mentees@lists.linuxfoundation.org>,
Shuah Khan <skhan@linuxfoundation.org>,
syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com
Subject: Re: [PATCH v3] xfrm: Update ipcomp_scratches with NULL if not allocated
Date: Thu, 1 Sep 2022 13:03:53 +0600 [thread overview]
Message-ID: <CAABMjtGgv1GP0F9TJCMFN2psx7ok23BR9pEOyemWHeKvc_LfqA@mail.gmail.com> (raw)
In-Reply-To: <YxAyd6++6oWPu9L1@gondor.apana.org.au>
On Thu, Sep 1, 2022 at 10:18 AM Herbert Xu <herbert@gondor.apana.org.au> wrote:
>
> On Thu, Sep 01, 2022 at 10:03:07AM +0600, Khalid Masum wrote:
> >
> > diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
> > index cb40ff0ff28d..3774d07c5819 100644
> > --- a/net/xfrm/xfrm_ipcomp.c
> > +++ b/net/xfrm/xfrm_ipcomp.c
> > @@ -203,6 +203,7 @@ static void ipcomp_free_scratches(void)
> > vfree(*per_cpu_ptr(scratches, i));
> >
> > free_percpu(scratches);
> > + ipcomp_scratches = NULL;
> > }
>
> Good catch! This is probably the root cause of all the crashes.
>
> > static void * __percpu *ipcomp_alloc_scratches(void)
> > @@ -215,7 +216,7 @@ static void * __percpu *ipcomp_alloc_scratches(void)
> >
> > scratches = alloc_percpu(void *);
> > if (!scratches)
> > - return NULL;
> > + return ipcomp_scratches = NULL;
>
> This is unnecessary as with your first hunk, ipcomp_scratches
> is guaranteed to be NULL.
>
> Thanks,
> --
You are right. Instead of setting it to NULL at both places, it makes
more sense to
do it when memory is freed.
I shall send a v4 with the suggested change.
thanks,
-- Khalid Masum
next prev parent reply other threads:[~2022-09-01 7:04 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-16 7:01 WARNING in __vunmap syzbot
2019-09-08 7:05 ` syzbot
2021-08-04 5:35 ` [syzbot] " syzbot
2022-08-31 1:41 ` [PATCH] xfrm: Don't increase scratch users if allocation fails Khalid Masum
2022-08-31 9:13 ` Herbert Xu
2022-08-31 12:01 ` Khalid Masum
2022-08-31 14:29 ` [PATCH v2] xfrm: ipcomp: Update ipcomp_scratches with NULL if alloc fails Khalid Masum
2022-08-31 14:58 ` Greg KH
2022-09-01 4:03 ` [PATCH v3] xfrm: Update ipcomp_scratches with NULL if not allocated Khalid Masum
2022-09-01 4:17 ` Herbert Xu
2022-09-01 7:03 ` Khalid Masum [this message]
2022-09-01 7:12 ` [PATCH v4] xfrm: Update ipcomp_scratches with NULL when freed Khalid Masum
2022-09-01 7:48 ` Herbert Xu
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