[v2] wifi: mt76: add a check of vzalloc in mt7615_coredump_work

[PATCH v2] wifi: mt76: add a check of vzalloc in mt7615_coredump_work

Posted by void0red 1 year, 6 months ago

From: Kang Chen <void0red@gmail.com>

vzalloc may fails, dump might be null and will cause
illegal address access later.

Fixes: d2bf7959d9c0 ("mt76: mt7663: introduce coredump support")
Signed-off-by: Kang Chen <void0red@gmail.com>
---
v2 -> v1: add Fixes tag

 drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
index a95602473..73d84c301 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
@@ -2367,6 +2367,9 @@ void mt7615_coredump_work(struct work_struct *work)
 	}
 
 	dump = vzalloc(MT76_CONNAC_COREDUMP_SZ);
+	if (!dump)
+		return;
+
 	data = dump;
 
 	while (true) {
-- 
2.34.1

Re: [PATCH v2] wifi: mt76: add a check of vzalloc in mt7615_coredump_work

Posted by Lorenzo Bianconi 1 year, 6 months ago

> From: Kang Chen <void0red@gmail.com>
> 
> vzalloc may fails, dump might be null and will cause
> illegal address access later.
> 
> Fixes: d2bf7959d9c0 ("mt76: mt7663: introduce coredump support")
> Signed-off-by: Kang Chen <void0red@gmail.com>
> ---
> v2 -> v1: add Fixes tag
> 
>  drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> index a95602473..73d84c301 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> @@ -2367,6 +2367,9 @@ void mt7615_coredump_work(struct work_struct *work)
>  	}
>  
>  	dump = vzalloc(MT76_CONNAC_COREDUMP_SZ);
> +	if (!dump)
> +		return;
> +
>  	data = dump;
>  
>  	while (true) {
> -- 
> 2.34.1
> 

revieweing the code I guess the right approach would be the one used in
mt7921_coredump_work():
- free pending skbs
- not run dev_coredumpv()

What do you think?

Regards,
Lorenzo

Re: [PATCH v2] wifi: mt76: add a check of vzalloc in mt7615_coredump_work

Posted by Kang Chen 1 year, 6 months ago

Hi, Lorenzo

Thanks for your suggestions.
I totally agree with you.

Best regards,
Kang Chen

On Mon, Feb 27, 2023 at 10:07 PM Lorenzo Bianconi
<lorenzo.bianconi@redhat.com> wrote:
>
> > From: Kang Chen <void0red@gmail.com>
> >
> > vzalloc may fails, dump might be null and will cause
> > illegal address access later.
> >
> > Fixes: d2bf7959d9c0 ("mt76: mt7663: introduce coredump support")
> > Signed-off-by: Kang Chen <void0red@gmail.com>
> > ---
> > v2 -> v1: add Fixes tag
> >
> >  drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> > index a95602473..73d84c301 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> > @@ -2367,6 +2367,9 @@ void mt7615_coredump_work(struct work_struct *work)
> >       }
> >
> >       dump = vzalloc(MT76_CONNAC_COREDUMP_SZ);
> > +     if (!dump)
> > +             return;
> > +
> >       data = dump;
> >
> >       while (true) {
> > --
> > 2.34.1
> >
>
> revieweing the code I guess the right approach would be the one used in
> mt7921_coredump_work():
> - free pending skbs
> - not run dev_coredumpv()
>
> What do you think?
>
> Regards,
> Lorenzo

[PATCH v3] wifi: mt76: handle failure of vzalloc in mt7615_coredump_work

Posted by void0red 1 year, 6 months ago

From: Kang Chen <void0red@gmail.com>

vzalloc may fails, dump might be null and will cause
illegal address access later.

Link: https://lore.kernel.org/all/Y%2Fy5Asxw3T3m4jCw@lore-desk
Fixes: d2bf7959d9c0 ("mt76: mt7663: introduce coredump support")
Signed-off-by: Kang Chen <void0red@gmail.com>
---
v3 -> v2: fix bugs
v2 -> v1: add Fixes tag

 drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
index a95602473..796768011 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
@@ -2380,7 +2380,7 @@ void mt7615_coredump_work(struct work_struct *work)
 			break;
 
 		skb_pull(skb, sizeof(struct mt7615_mcu_rxd));
-		if (data + skb->len - dump > MT76_CONNAC_COREDUMP_SZ) {
+		if (!dump || data + skb->len - dump > MT76_CONNAC_COREDUMP_SZ) {
 			dev_kfree_skb(skb);
 			continue;
 		}
@@ -2390,6 +2390,8 @@ void mt7615_coredump_work(struct work_struct *work)
 
 		dev_kfree_skb(skb);
 	}
-	dev_coredumpv(dev->mt76.dev, dump, MT76_CONNAC_COREDUMP_SZ,
-		      GFP_KERNEL);
+
+	if (dump)
+		dev_coredumpv(dev->mt76.dev, dump, MT76_CONNAC_COREDUMP_SZ,
+			      GFP_KERNEL);
 }
-- 
2.34.1

Re: [PATCH v3] wifi: mt76: handle failure of vzalloc in mt7615_coredump_work

Posted by Simon Horman 1 year, 6 months ago

On Mon, Feb 27, 2023 at 10:48:23PM +0800, void0red wrote:
> From: Kang Chen <void0red@gmail.com>
> 
> vzalloc may fails, dump might be null and will cause
> illegal address access later.
> 
> Link: https://lore.kernel.org/all/Y%2Fy5Asxw3T3m4jCw@lore-desk
> Fixes: d2bf7959d9c0 ("mt76: mt7663: introduce coredump support")
> Signed-off-by: Kang Chen <void0red@gmail.com>

Reviewed-by: Simon Horman <simon.horman@corigine.com>