[PATCH] aoe: fix the potential use-after-free problem in more places

[PATCH] aoe: fix the potential use-after-free problem in more places

[Lee, Chun-Yi]

From: Chun-Yi Lee <jlee@suse.com>

For fixing CVE-2023-6270, f98364e92662 patch moved dev_put() from
aoecmd_cfg_pkts() to tx() to avoid that the tx() runs into use-after-free.

But Nicolai Stange found more places in aoe have potential use-after-free
problem with tx(). e.g. revalidate(), aoecmd_ata_rw(), resend(), probe()
and aoecmd_cfg_rsp(). Those functions also use aoenet_xmit() to push
packet to tx queue. So they should also use dev_hold() to increase the
refcnt of skb->dev.

This patch adds dev_hold() to those functions and also uses dev_put()
when the skb_clone() returns NULL.

Link: https://nvd.nist.gov/vuln/detail/CVE-2023-6270
Fixes: f98364e92662 ("aoe: fix the potential use-after-free problem in
aoecmd_cfg_pkts")
Reported-by: Nicolai Stange <nstange@suse.com>
Signed-off-by: Chun-Yi Lee <jlee@suse.com>
---
 drivers/block/aoe/aoecmd.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index cc9077b588d7..fcedbad8e3be 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -361,6 +361,7 @@ ata_rw_frameinit(struct frame *f)
 	}
 
 	ah->cmdstat = ATA_CMD_PIO_READ | writebit | extbit;
+	dev_hold(t->ifp->nd);
 	skb->dev = t->ifp->nd;
 }
 
@@ -401,7 +402,8 @@ aoecmd_ata_rw(struct aoedev *d)
 		__skb_queue_head_init(&queue);
 		__skb_queue_tail(&queue, skb);
 		aoenet_xmit(&queue);
-	}
+	} else
+		dev_put(f->t->ifp->nd);
 	return 1;
 }
 
@@ -483,10 +485,13 @@ resend(struct aoedev *d, struct frame *f)
 	memcpy(h->dst, t->addr, sizeof h->dst);
 	memcpy(h->src, t->ifp->nd->dev_addr, sizeof h->src);
 
+	dev_hold(t->ifp->nd);
 	skb->dev = t->ifp->nd;
 	skb = skb_clone(skb, GFP_ATOMIC);
-	if (skb == NULL)
+	if (skb == NULL) {
+		dev_put(t->ifp->nd);
 		return;
+	}
 	f->sent = ktime_get();
 	__skb_queue_head_init(&queue);
 	__skb_queue_tail(&queue, skb);
@@ -617,7 +622,8 @@ probe(struct aoetgt *t)
 		__skb_queue_head_init(&queue);
 		__skb_queue_tail(&queue, skb);
 		aoenet_xmit(&queue);
-	}
+	} else
+		dev_put(f->t->ifp->nd);
 }
 
 static long
@@ -1395,6 +1401,7 @@ aoecmd_ata_id(struct aoedev *d)
 	ah->cmdstat = ATA_CMD_ID_ATA;
 	ah->lba3 = 0xa0;
 
+	dev_hold(t->ifp->nd);
 	skb->dev = t->ifp->nd;
 
 	d->rttavg = RTTAVG_INIT;
@@ -1404,6 +1411,8 @@ aoecmd_ata_id(struct aoedev *d)
 	skb = skb_clone(skb, GFP_ATOMIC);
 	if (skb)
 		f->sent = ktime_get();
+	else
+		dev_put(t->ifp->nd);
 
 	return skb;
 }
-- 
2.35.3

Re: [PATCH] aoe: fix the potential use-after-free problem in more places

[joeyli]

Hi Justin, 

On Wed, Apr 10, 2024 at 09:48:58PM +0800, Lee, Chun-Yi wrote:
> From: Chun-Yi Lee <jlee@suse.com>
> 
> For fixing CVE-2023-6270, f98364e92662 patch moved dev_put() from
> aoecmd_cfg_pkts() to tx() to avoid that the tx() runs into use-after-free.
> 
> But Nicolai Stange found more places in aoe have potential use-after-free
> problem with tx(). e.g. revalidate(), aoecmd_ata_rw(), resend(), probe()
> and aoecmd_cfg_rsp(). Those functions also use aoenet_xmit() to push
> packet to tx queue. So they should also use dev_hold() to increase the
> refcnt of skb->dev.
> 
> This patch adds dev_hold() to those functions and also uses dev_put()
> when the skb_clone() returns NULL.
> 
> Link: https://nvd.nist.gov/vuln/detail/CVE-2023-6270
> Fixes: f98364e92662 ("aoe: fix the potential use-after-free problem in
> aoecmd_cfg_pkts")
> Reported-by: Nicolai Stange <nstange@suse.com>
> Signed-off-by: Chun-Yi Lee <jlee@suse.com>

Do you have any suggestion for this patch? or I missed anything?

Thanks a lot!
Joey Lee

> ---
>  drivers/block/aoe/aoecmd.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
> index cc9077b588d7..fcedbad8e3be 100644
> --- a/drivers/block/aoe/aoecmd.c
> +++ b/drivers/block/aoe/aoecmd.c
> @@ -361,6 +361,7 @@ ata_rw_frameinit(struct frame *f)
>  	}
>  
>  	ah->cmdstat = ATA_CMD_PIO_READ | writebit | extbit;
> +	dev_hold(t->ifp->nd);
>  	skb->dev = t->ifp->nd;
>  }
>  
> @@ -401,7 +402,8 @@ aoecmd_ata_rw(struct aoedev *d)
>  		__skb_queue_head_init(&queue);
>  		__skb_queue_tail(&queue, skb);
>  		aoenet_xmit(&queue);
> -	}
> +	} else
> +		dev_put(f->t->ifp->nd);
>  	return 1;
>  }
>  
> @@ -483,10 +485,13 @@ resend(struct aoedev *d, struct frame *f)
>  	memcpy(h->dst, t->addr, sizeof h->dst);
>  	memcpy(h->src, t->ifp->nd->dev_addr, sizeof h->src);
>  
> +	dev_hold(t->ifp->nd);
>  	skb->dev = t->ifp->nd;
>  	skb = skb_clone(skb, GFP_ATOMIC);
> -	if (skb == NULL)
> +	if (skb == NULL) {
> +		dev_put(t->ifp->nd);
>  		return;
> +	}
>  	f->sent = ktime_get();
>  	__skb_queue_head_init(&queue);
>  	__skb_queue_tail(&queue, skb);
> @@ -617,7 +622,8 @@ probe(struct aoetgt *t)
>  		__skb_queue_head_init(&queue);
>  		__skb_queue_tail(&queue, skb);
>  		aoenet_xmit(&queue);
> -	}
> +	} else
> +		dev_put(f->t->ifp->nd);
>  }
>  
>  static long
> @@ -1395,6 +1401,7 @@ aoecmd_ata_id(struct aoedev *d)
>  	ah->cmdstat = ATA_CMD_ID_ATA;
>  	ah->lba3 = 0xa0;
>  
> +	dev_hold(t->ifp->nd);
>  	skb->dev = t->ifp->nd;
>  
>  	d->rttavg = RTTAVG_INIT;
> @@ -1404,6 +1411,8 @@ aoecmd_ata_id(struct aoedev *d)
>  	skb = skb_clone(skb, GFP_ATOMIC);
>  	if (skb)
>  		f->sent = ktime_get();
> +	else
> +		dev_put(t->ifp->nd);
>  
>  	return skb;
>  }
> -- 
> 2.35.3

Re: [PATCH] aoe: fix the potential use-after-free problem in more places

[Markus Elfring]

> For fixing CVE-2023-6270, f98364e92662 patch moved dev_put() from
…

Please add a subject for the mentioned commit hash.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9-rc6#n99


> This patch adds dev_hold() to those functions and also uses dev_put()
> when the skb_clone() returns NULL.

Please improve this change description with a corresponding imperative wording.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9-rc6#n94


…
> Fixes: f98364e92662 ("aoe: fix the potential use-after-free problem in
> aoecmd_cfg_pkts")

I suggest to omit a line break for this tag.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9-rc6#n145


…
> +++ b/drivers/block/aoe/aoecmd.c
…
> @@ -401,7 +402,8 @@ aoecmd_ata_rw(struct aoedev *d)
>  		__skb_queue_head_init(&queue);
>  		__skb_queue_tail(&queue, skb);
>  		aoenet_xmit(&queue);
> -	}
> +	} else
> +		dev_put(f->t->ifp->nd);
>  	return 1;
>  }
>
…
> @@ -617,7 +622,8 @@ probe(struct aoetgt *t)
>  		__skb_queue_head_init(&queue);
>  		__skb_queue_tail(&queue, skb);
>  		aoenet_xmit(&queue);
> -	}
> +	} else
> +		dev_put(f->t->ifp->nd);
>  }
>
>  static long
…

Should curly brackets be used for both if branches in these function implementations?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?h=v6.9-rc6#n213

Regards,
Markus

Re: [PATCH] aoe: fix the potential use-after-free problem in more places

[joeyli]

Hi Markus,

Thanks for your review! I will send v2 patch.

Joey Lee

On Tue, Apr 30, 2024 at 06:16:00PM +0200, Markus Elfring wrote:
> > For fixing CVE-2023-6270, f98364e92662 patch moved dev_put() from
> …
> 
> Please add a subject for the mentioned commit hash.
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9-rc6#n99
> 
> 
> > This patch adds dev_hold() to those functions and also uses dev_put()
> > when the skb_clone() returns NULL.
> 
> Please improve this change description with a corresponding imperative wording.
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9-rc6#n94
> 
> 
> …
> > Fixes: f98364e92662 ("aoe: fix the potential use-after-free problem in
> > aoecmd_cfg_pkts")
> 
> I suggest to omit a line break for this tag.
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9-rc6#n145
> 
> 
> …
> > +++ b/drivers/block/aoe/aoecmd.c
> …
> > @@ -401,7 +402,8 @@ aoecmd_ata_rw(struct aoedev *d)
> >  		__skb_queue_head_init(&queue);
> >  		__skb_queue_tail(&queue, skb);
> >  		aoenet_xmit(&queue);
> > -	}
> > +	} else
> > +		dev_put(f->t->ifp->nd);
> >  	return 1;
> >  }
> >
> …
> > @@ -617,7 +622,8 @@ probe(struct aoetgt *t)
> >  		__skb_queue_head_init(&queue);
> >  		__skb_queue_tail(&queue, skb);
> >  		aoenet_xmit(&queue);
> > -	}
> > +	} else
> > +		dev_put(f->t->ifp->nd);
> >  }
> >
> >  static long
> …
> 
> Should curly brackets be used for both if branches in these function implementations?
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?h=v6.9-rc6#n213
> 
> Regards,
> Markus

[PATCH] aoe: fix the potential use-after-free problem in more places

[Lee, Chun-Yi]

From: Chun-Yi Lee <jlee@suse.com>

For fixing CVE-2023-6270, f98364e92662 ("aoe: fix the potential
use-after-free problem in aoecmd_cfg_pkts") make tx() do dev_put()
instead of doing in aoecmd_cfg_pkts(). It avoids that the tx() runs
into use-after-free.

But Nicolai Stange found more places in aoe have potential use-after-free
problem with tx(). e.g. revalidate(), aoecmd_ata_rw(), resend(), probe()
and aoecmd_cfg_rsp(). Those functions also use aoenet_xmit() to push
packet to tx queue. So they should also use dev_hold() to increase the
refcnt of skb->dev.

This patch adds dev_hold() to those functions and also uses dev_put()
when the skb_clone() returns NULL.

v2:
- Base on submitting-patches.rst document to improve patch description.
- Used curly brackets in the if-else blocks.

Link: https://nvd.nist.gov/vuln/detail/CVE-2023-6270
Fixes: f98364e92662 ("aoe: fix the potential use-after-free problem in aoecmd_cfg_pkts")
Reported-by: Nicolai Stange <nstange@suse.com>
Signed-off-by: Chun-Yi Lee <jlee@suse.com>
---
 drivers/block/aoe/aoecmd.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index cc9077b588d7..d1f4ddc57645 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -361,6 +361,7 @@ ata_rw_frameinit(struct frame *f)
 	}
 
 	ah->cmdstat = ATA_CMD_PIO_READ | writebit | extbit;
+	dev_hold(t->ifp->nd);
 	skb->dev = t->ifp->nd;
 }
 
@@ -401,6 +402,8 @@ aoecmd_ata_rw(struct aoedev *d)
 		__skb_queue_head_init(&queue);
 		__skb_queue_tail(&queue, skb);
 		aoenet_xmit(&queue);
+	} else {
+		dev_put(f->t->ifp->nd);
 	}
 	return 1;
 }
@@ -483,10 +486,13 @@ resend(struct aoedev *d, struct frame *f)
 	memcpy(h->dst, t->addr, sizeof h->dst);
 	memcpy(h->src, t->ifp->nd->dev_addr, sizeof h->src);
 
+	dev_hold(t->ifp->nd);
 	skb->dev = t->ifp->nd;
 	skb = skb_clone(skb, GFP_ATOMIC);
-	if (skb == NULL)
+	if (skb == NULL) {
+		dev_put(t->ifp->nd);
 		return;
+	}
 	f->sent = ktime_get();
 	__skb_queue_head_init(&queue);
 	__skb_queue_tail(&queue, skb);
@@ -617,6 +623,8 @@ probe(struct aoetgt *t)
 		__skb_queue_head_init(&queue);
 		__skb_queue_tail(&queue, skb);
 		aoenet_xmit(&queue);
+	} else {
+		dev_put(f->t->ifp->nd);
 	}
 }
 
@@ -1395,6 +1403,7 @@ aoecmd_ata_id(struct aoedev *d)
 	ah->cmdstat = ATA_CMD_ID_ATA;
 	ah->lba3 = 0xa0;
 
+	dev_hold(t->ifp->nd);
 	skb->dev = t->ifp->nd;
 
 	d->rttavg = RTTAVG_INIT;
@@ -1404,6 +1413,8 @@ aoecmd_ata_id(struct aoedev *d)
 	skb = skb_clone(skb, GFP_ATOMIC);
 	if (skb)
 		f->sent = ktime_get();
+	else
+		dev_put(t->ifp->nd);
 
 	return skb;
 }
-- 
2.35.3

Re: [PATCH] aoe: fix the potential use-after-free problem in more places

[Markus Elfring]

Please add a version identification to your patch subject.


…
> This patch adds …

Please use imperative wordings for improved change descriptions also in your patches.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9#n94


> v2:
> - Base on submitting-patches.rst document to improve patch description.
…

* Was any information overlooked here?

* Such version descriptions should be put behind a marker line.


Regards,
Markus