From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: Austin Kim <austindh.kim@gmail.com>,
mchehab@kernel.org, khilman@baylibre.com
Cc: mjourdan@baylibre.com, gregkh@linuxfoundation.org,
linux-media@vger.kernel.org, linux-amlogic@lists.infradead.org,
devel@driverdev.osuosl.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] media: meson: Add NULL check after the call to kmalloc()
Date: Wed, 4 Sep 2019 10:43:20 +0200 [thread overview]
Message-ID: <a9ca05ec-55a9-a58c-267a-334771a1480a@rasmusvillemoes.dk> (raw)
In-Reply-To: <20190904082232.GA171180@LGEARND20B15>
On 04/09/2019 10.22, Austin Kim wrote:
> If the kmalloc() return NULL, the NULL pointer dereference will occur.
> new_ts->ts = ts;
>
> Add exception check after the call to kmalloc() is made.
>
> Signed-off-by: Austin Kim <austindh.kim@gmail.com>
> ---
> drivers/staging/media/meson/vdec/vdec_helpers.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c
> index f16948b..e7e56d5 100644
> --- a/drivers/staging/media/meson/vdec/vdec_helpers.c
> +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
> @@ -206,6 +206,10 @@ void amvdec_add_ts_reorder(struct amvdec_session *sess, u64 ts, u32 offset)
> unsigned long flags;
>
> new_ts = kmalloc(sizeof(*new_ts), GFP_KERNEL);
> + if (!new_ts) {
> + dev_err(sess->core->dev, "Failed to kmalloc()\n");
> + return;
> + }
> new_ts->ts = ts;
> new_ts->offset = offset;
No need to printk() on error, AFAIK the mm subsystem should already make
some noise if an allocation fails.
This is not a proper fix - you need to make the function return an error
(-ENOMEM) to let the caller know allocation failed, and allow that to
propagate the error. There's only one caller, which already seems
capable of returning errors (there's an -EAGAIN), so it shouldn't be
that hard - though of course one needs to undo what has been done so far.
Also, unrelated to the kmalloc() handling: amvdec_add_ts_reorder() could
be moved to esparser.c and made static, or at the very least the
EXPORT_SYMBOL can be removed since vdec_helpers.o is linked in to the
same module as the sole user. That probably goes for all the
EXPORT_SYMBOL(amvdec_*).
Rasmus
WARNING: multiple messages have this Message-ID (diff)
From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: Austin Kim <austindh.kim@gmail.com>,
mchehab@kernel.org, khilman@baylibre.com
Cc: mjourdan@baylibre.com, devel@driverdev.osuosl.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-amlogic@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-media@vger.kernel.org
Subject: Re: [PATCH] media: meson: Add NULL check after the call to kmalloc()
Date: Wed, 4 Sep 2019 10:43:20 +0200 [thread overview]
Message-ID: <a9ca05ec-55a9-a58c-267a-334771a1480a@rasmusvillemoes.dk> (raw)
In-Reply-To: <20190904082232.GA171180@LGEARND20B15>
On 04/09/2019 10.22, Austin Kim wrote:
> If the kmalloc() return NULL, the NULL pointer dereference will occur.
> new_ts->ts = ts;
>
> Add exception check after the call to kmalloc() is made.
>
> Signed-off-by: Austin Kim <austindh.kim@gmail.com>
> ---
> drivers/staging/media/meson/vdec/vdec_helpers.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c
> index f16948b..e7e56d5 100644
> --- a/drivers/staging/media/meson/vdec/vdec_helpers.c
> +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
> @@ -206,6 +206,10 @@ void amvdec_add_ts_reorder(struct amvdec_session *sess, u64 ts, u32 offset)
> unsigned long flags;
>
> new_ts = kmalloc(sizeof(*new_ts), GFP_KERNEL);
> + if (!new_ts) {
> + dev_err(sess->core->dev, "Failed to kmalloc()\n");
> + return;
> + }
> new_ts->ts = ts;
> new_ts->offset = offset;
No need to printk() on error, AFAIK the mm subsystem should already make
some noise if an allocation fails.
This is not a proper fix - you need to make the function return an error
(-ENOMEM) to let the caller know allocation failed, and allow that to
propagate the error. There's only one caller, which already seems
capable of returning errors (there's an -EAGAIN), so it shouldn't be
that hard - though of course one needs to undo what has been done so far.
Also, unrelated to the kmalloc() handling: amvdec_add_ts_reorder() could
be moved to esparser.c and made static, or at the very least the
EXPORT_SYMBOL can be removed since vdec_helpers.o is linked in to the
same module as the sole user. That probably goes for all the
EXPORT_SYMBOL(amvdec_*).
Rasmus
_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
WARNING: multiple messages have this Message-ID (diff)
From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: Austin Kim <austindh.kim@gmail.com>,
mchehab@kernel.org, khilman@baylibre.com
Cc: mjourdan@baylibre.com, devel@driverdev.osuosl.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-amlogic@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-media@vger.kernel.org
Subject: Re: [PATCH] media: meson: Add NULL check after the call to kmalloc()
Date: Wed, 4 Sep 2019 10:43:20 +0200 [thread overview]
Message-ID: <a9ca05ec-55a9-a58c-267a-334771a1480a@rasmusvillemoes.dk> (raw)
In-Reply-To: <20190904082232.GA171180@LGEARND20B15>
On 04/09/2019 10.22, Austin Kim wrote:
> If the kmalloc() return NULL, the NULL pointer dereference will occur.
> new_ts->ts = ts;
>
> Add exception check after the call to kmalloc() is made.
>
> Signed-off-by: Austin Kim <austindh.kim@gmail.com>
> ---
> drivers/staging/media/meson/vdec/vdec_helpers.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c
> index f16948b..e7e56d5 100644
> --- a/drivers/staging/media/meson/vdec/vdec_helpers.c
> +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
> @@ -206,6 +206,10 @@ void amvdec_add_ts_reorder(struct amvdec_session *sess, u64 ts, u32 offset)
> unsigned long flags;
>
> new_ts = kmalloc(sizeof(*new_ts), GFP_KERNEL);
> + if (!new_ts) {
> + dev_err(sess->core->dev, "Failed to kmalloc()\n");
> + return;
> + }
> new_ts->ts = ts;
> new_ts->offset = offset;
No need to printk() on error, AFAIK the mm subsystem should already make
some noise if an allocation fails.
This is not a proper fix - you need to make the function return an error
(-ENOMEM) to let the caller know allocation failed, and allow that to
propagate the error. There's only one caller, which already seems
capable of returning errors (there's an -EAGAIN), so it shouldn't be
that hard - though of course one needs to undo what has been done so far.
Also, unrelated to the kmalloc() handling: amvdec_add_ts_reorder() could
be moved to esparser.c and made static, or at the very least the
EXPORT_SYMBOL can be removed since vdec_helpers.o is linked in to the
same module as the sole user. That probably goes for all the
EXPORT_SYMBOL(amvdec_*).
Rasmus
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: Austin Kim <austindh.kim@gmail.com>,
mchehab@kernel.org, khilman@baylibre.com
Cc: mjourdan@baylibre.com, devel@driverdev.osuosl.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-amlogic@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-media@vger.kernel.org
Subject: Re: [PATCH] media: meson: Add NULL check after the call to kmalloc()
Date: Wed, 4 Sep 2019 10:43:20 +0200 [thread overview]
Message-ID: <a9ca05ec-55a9-a58c-267a-334771a1480a@rasmusvillemoes.dk> (raw)
In-Reply-To: <20190904082232.GA171180@LGEARND20B15>
On 04/09/2019 10.22, Austin Kim wrote:
> If the kmalloc() return NULL, the NULL pointer dereference will occur.
> new_ts->ts = ts;
>
> Add exception check after the call to kmalloc() is made.
>
> Signed-off-by: Austin Kim <austindh.kim@gmail.com>
> ---
> drivers/staging/media/meson/vdec/vdec_helpers.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c
> index f16948b..e7e56d5 100644
> --- a/drivers/staging/media/meson/vdec/vdec_helpers.c
> +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
> @@ -206,6 +206,10 @@ void amvdec_add_ts_reorder(struct amvdec_session *sess, u64 ts, u32 offset)
> unsigned long flags;
>
> new_ts = kmalloc(sizeof(*new_ts), GFP_KERNEL);
> + if (!new_ts) {
> + dev_err(sess->core->dev, "Failed to kmalloc()\n");
> + return;
> + }
> new_ts->ts = ts;
> new_ts->offset = offset;
No need to printk() on error, AFAIK the mm subsystem should already make
some noise if an allocation fails.
This is not a proper fix - you need to make the function return an error
(-ENOMEM) to let the caller know allocation failed, and allow that to
propagate the error. There's only one caller, which already seems
capable of returning errors (there's an -EAGAIN), so it shouldn't be
that hard - though of course one needs to undo what has been done so far.
Also, unrelated to the kmalloc() handling: amvdec_add_ts_reorder() could
be moved to esparser.c and made static, or at the very least the
EXPORT_SYMBOL can be removed since vdec_helpers.o is linked in to the
same module as the sole user. That probably goes for all the
EXPORT_SYMBOL(amvdec_*).
Rasmus
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
next prev parent reply other threads:[~2019-09-04 8:43 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 8:22 [PATCH] media: meson: Add NULL check after the call to kmalloc() Austin Kim
2019-09-04 8:22 ` Austin Kim
2019-09-04 8:22 ` Austin Kim
2019-09-04 8:22 ` Austin Kim
2019-09-04 8:43 ` Rasmus Villemoes [this message]
2019-09-04 8:43 ` Rasmus Villemoes
2019-09-04 8:43 ` Rasmus Villemoes
2019-09-04 8:43 ` Rasmus Villemoes
2019-09-04 22:47 ` Austin Kim
2019-09-04 22:47 ` Austin Kim
2019-09-04 22:47 ` Austin Kim
2019-09-04 22:47 ` Austin Kim
2019-09-04 8:45 ` Greg KH
2019-09-04 8:45 ` Greg KH
2019-09-04 8:45 ` Greg KH
2019-09-04 8:45 ` Greg KH
2019-09-04 22:39 ` Austin Kim
2019-09-04 22:39 ` Austin Kim
2019-09-04 22:39 ` Austin Kim
2019-09-04 22:39 ` Austin Kim
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