diff mbox series

[v4] Bluetooth: btmtk: Fix null pointer when processing coredump

Message ID 20230712130218.376-1-chris.lu@mediatek.com (mailing list archive)
State New, archived
Headers show
Series [v4] Bluetooth: btmtk: Fix null pointer when processing coredump | expand

Commit Message

Chris Lu July 12, 2023, 1:02 p.m. UTC 
There may be a potential null pointer risk if offset value is
less than 0 when doing memcmp in btmtk_process_coredump().
Check offset is valid before doing memcmp.

Signed-off-by: Chris Lu <chris.lu@mediatek.com>
Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
v2: fix typo
v3: fix bot checking error
v4: reduce variable 'offset' declaration in v3
---
 drivers/bluetooth/btmtk.c | 12 ++++++------
 drivers/bluetooth/btmtk.h |  1 +
 2 files changed, 7 insertions(+), 6 deletions(-)

Comments

Markus Elfring July 12, 2023, 7:52 p.m. UTC | #1 
…
> v4: reduce variable 'offset' declaration in v3
> ---
>  drivers/bluetooth/btmtk.c | 12 ++++++------
…

I suggest to replace the marker by a line break.

See also:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.5-rc1#n711


Would it be helpful to adjust the wording “Fix null pointer” in the subject?


How do you think about to add the tag “Fixes”?

Regards,
Markus
Luiz Augusto von Dentz July 12, 2023, 8:29 p.m. UTC | #2 
Hi Chris,

On Wed, Jul 12, 2023 at 6:03 AM Chris Lu <chris.lu@mediatek.com> wrote:
>
> There may be a potential null pointer risk if offset value is
> less than 0 when doing memcmp in btmtk_process_coredump().
> Check offset is valid before doing memcmp.
>
> Signed-off-by: Chris Lu <chris.lu@mediatek.com>
> Co-developed-by: Sean Wang <sean.wang@mediatek.com>
> Signed-off-by: Sean Wang <sean.wang@mediatek.com>

You should probably include the Fixes tag of the patch that introduced
the problem.

> ---
> v2: fix typo
> v3: fix bot checking error
> v4: reduce variable 'offset' declaration in v3
> ---
>  drivers/bluetooth/btmtk.c | 12 ++++++------
>  drivers/bluetooth/btmtk.h |  1 +
>  2 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
> index 786f775196ae..9cc789272ab7 100644
> --- a/drivers/bluetooth/btmtk.c
> +++ b/drivers/bluetooth/btmtk.c
> @@ -395,12 +395,12 @@ int btmtk_process_coredump(struct hci_dev *hdev, struct sk_buff *skb)
>
>                 /* Mediatek coredump data would be more than MTK_COREDUMP_NUM */
>                 if (data->cd_info.cnt > MTK_COREDUMP_NUM &&
> -                   skb->len > sizeof(MTK_COREDUMP_END) &&
> -                   !memcmp((char *)&skb->data[skb->len - sizeof(MTK_COREDUMP_END)],
> -                           MTK_COREDUMP_END, sizeof(MTK_COREDUMP_END) - 1)) {
> -                       bt_dev_info(hdev, "Mediatek coredump end");
> -                       hci_devcd_complete(hdev);
> -               }
> +                   skb->len > MTK_COREDUMP_END_LEN)
> +                       if (!memcmp((char *)&skb->data[skb->len - MTK_COREDUMP_END_LEN],
> +                           MTK_COREDUMP_END, MTK_COREDUMP_END_LEN - 1)) {
> +                               bt_dev_info(hdev, "Mediatek coredump end");
> +                               hci_devcd_complete(hdev);
> +                       }
>
>                 break;
>         }
> diff --git a/drivers/bluetooth/btmtk.h b/drivers/bluetooth/btmtk.h
> index 68309dfe076a..56f5502baadf 100644
> --- a/drivers/bluetooth/btmtk.h
> +++ b/drivers/bluetooth/btmtk.h
> @@ -24,6 +24,7 @@
>
>  #define MTK_COREDUMP_SIZE              (1024 * 1000)
>  #define MTK_COREDUMP_END               "coredump end"
> +#define MTK_COREDUMP_END_LEN           (sizeof(MTK_COREDUMP_END))
>  #define MTK_COREDUMP_NUM               255
>
>  enum {
> --
> 2.18.0
>
Chris Lu July 13, 2023, 6:10 a.m. UTC | #3 
On Wed, 2023-07-12 at 13:29 -0700, Luiz Augusto von Dentz wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  Hi Chris,
> 
> On Wed, Jul 12, 2023 at 6:03 AM Chris Lu <chris.lu@mediatek.com>
> wrote:
> >
> > There may be a potential null pointer risk if offset value is
> > less than 0 when doing memcmp in btmtk_process_coredump().
> > Check offset is valid before doing memcmp.
> >
> > Signed-off-by: Chris Lu <chris.lu@mediatek.com>
> > Co-developed-by: Sean Wang <sean.wang@mediatek.com>
> > Signed-off-by: Sean Wang <sean.wang@mediatek.com>
> 
> You should probably include the Fixes tag of the patch that
> introduced
> the problem.
> 
Hi Luiz,

Thanks for reminding, I'll update Bug ad fixs info in commit message
and send the v5 patch.

BRs,
Chris

> > ---
> > v2: fix typo
> > v3: fix bot checking error
> > v4: reduce variable 'offset' declaration in v3
> > ---
> >  drivers/bluetooth/btmtk.c | 12 ++++++------
> >  drivers/bluetooth/btmtk.h |  1 +
> >  2 files changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
> > index 786f775196ae..9cc789272ab7 100644
> > --- a/drivers/bluetooth/btmtk.c
> > +++ b/drivers/bluetooth/btmtk.c
> > @@ -395,12 +395,12 @@ int btmtk_process_coredump(struct hci_dev
> *hdev, struct sk_buff *skb)
> >
> >                 /* Mediatek coredump data would be more than
> MTK_COREDUMP_NUM */
> >                 if (data->cd_info.cnt > MTK_COREDUMP_NUM &&
> > -                   skb->len > sizeof(MTK_COREDUMP_END) &&
> > -                   !memcmp((char *)&skb->data[skb->len -
> sizeof(MTK_COREDUMP_END)],
> > -                           MTK_COREDUMP_END,
> sizeof(MTK_COREDUMP_END) - 1)) {
> > -                       bt_dev_info(hdev, "Mediatek coredump end");
> > -                       hci_devcd_complete(hdev);
> > -               }
> > +                   skb->len > MTK_COREDUMP_END_LEN)
> > +                       if (!memcmp((char *)&skb->data[skb->len -
> MTK_COREDUMP_END_LEN],
> > +                           MTK_COREDUMP_END, MTK_COREDUMP_END_LEN
> - 1)) {
> > +                               bt_dev_info(hdev, "Mediatek
> coredump end");
> > +                               hci_devcd_complete(hdev);
> > +                       }
> >
> >                 break;
> >         }
> > diff --git a/drivers/bluetooth/btmtk.h b/drivers/bluetooth/btmtk.h
> > index 68309dfe076a..56f5502baadf 100644
> > --- a/drivers/bluetooth/btmtk.h
> > +++ b/drivers/bluetooth/btmtk.h
> > @@ -24,6 +24,7 @@
> >
> >  #define MTK_COREDUMP_SIZE              (1024 * 1000)
> >  #define MTK_COREDUMP_END               "coredump end"
> > +#define MTK_COREDUMP_END_LEN           (sizeof(MTK_COREDUMP_END))
> >  #define MTK_COREDUMP_NUM               255
> >
> >  enum {
> > --
> > 2.18.0
> >
> 
> 
> -- 
> Luiz Augusto von Dentz
diff mbox series

Patch

diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
index 786f775196ae..9cc789272ab7 100644
--- a/drivers/bluetooth/btmtk.c
+++ b/drivers/bluetooth/btmtk.c
@@ -395,12 +395,12 @@  int btmtk_process_coredump(struct hci_dev *hdev, struct sk_buff *skb)
 
 		/* Mediatek coredump data would be more than MTK_COREDUMP_NUM */
 		if (data->cd_info.cnt > MTK_COREDUMP_NUM &&
-		    skb->len > sizeof(MTK_COREDUMP_END) &&
-		    !memcmp((char *)&skb->data[skb->len - sizeof(MTK_COREDUMP_END)],
-			    MTK_COREDUMP_END, sizeof(MTK_COREDUMP_END) - 1)) {
-			bt_dev_info(hdev, "Mediatek coredump end");
-			hci_devcd_complete(hdev);
-		}
+		    skb->len > MTK_COREDUMP_END_LEN)
+			if (!memcmp((char *)&skb->data[skb->len - MTK_COREDUMP_END_LEN],
+			    MTK_COREDUMP_END, MTK_COREDUMP_END_LEN - 1)) {
+				bt_dev_info(hdev, "Mediatek coredump end");
+				hci_devcd_complete(hdev);
+			}
 
 		break;
 	}
diff --git a/drivers/bluetooth/btmtk.h b/drivers/bluetooth/btmtk.h
index 68309dfe076a..56f5502baadf 100644
--- a/drivers/bluetooth/btmtk.h
+++ b/drivers/bluetooth/btmtk.h
@@ -24,6 +24,7 @@ 
 
 #define MTK_COREDUMP_SIZE		(1024 * 1000)
 #define MTK_COREDUMP_END		"coredump end"
+#define MTK_COREDUMP_END_LEN		(sizeof(MTK_COREDUMP_END))
 #define MTK_COREDUMP_NUM		255
 
 enum {