[PATCH] media: meson: vdec: potential dereference of null pointer
Neil Armstrong
narmstrong at baylibre.com
Thu Dec 9 09:52:12 PST 2021
Hi,
On 09/12/2021 12:58, Hans Verkuil wrote:
> On 09/12/2021 09:58, Jiasheng Jiang wrote:
>> he return value of kzalloc() needs to be checked.
>> To avoid use of null pointer in case of the failure of alloc.
>>
>> Fixes: 876f123b8956 ("media: meson: vdec: bring up to compliance")
>> Signed-off-by: Jiasheng Jiang <jiasheng at iscas.ac.cn>
>> ---
>> drivers/staging/media/meson/vdec/vdec_helpers.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c
>> index 7f07a9175815..025885fcfec6 100644
>> --- a/drivers/staging/media/meson/vdec/vdec_helpers.c
>> +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
>> @@ -234,6 +234,8 @@ void amvdec_add_ts(struct amvdec_session *sess, u64 ts,
>> unsigned long flags;
>>
>> new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL);
>> + if (!new_ts)
>> + return;
>
> While this avoids dereferencing a NULL pointer, this error isn't propagated to the
> caller. And I'm not sure if that's right.
>
> Neil, what should be done in this case?
>
> Regards,
>
> Hans
>
>> new_ts->ts = ts;
>> new_ts->tc = tc;
>> new_ts->offset = offset;
>>
>
Probably something like this:
===================><=============================
diff --git a/drivers/staging/media/meson/vdec/esparser.c b/drivers/staging/media/meson/vdec/esparser.c
index db7022707ff8..df733eff9ac7 100644
--- a/drivers/staging/media/meson/vdec/esparser.c
+++ b/drivers/staging/media/meson/vdec/esparser.c
@@ -328,7 +328,11 @@ esparser_queue(struct amvdec_session *sess, struct vb2_v4l2_buffer *vbuf)
offset = esparser_get_offset(sess);
- amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags);
+ ret = amvdec_add_ts(sess, vb->timestamp, vbuf->timecode, offset, vbuf->flags);
+ if (ret) {
+ v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
+ return ret;
+ }
dev_dbg(core->dev, "esparser: ts = %llu pld_size = %u offset = %08X flags = %08X\n",
vb->timestamp, payload_size, offset, vbuf->flags);
diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c
index b9125c295d1d..593b2ccbece2 100644
--- a/drivers/staging/media/meson/vdec/vdec_helpers.c
+++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
@@ -227,13 +227,15 @@ int amvdec_set_canvases(struct amvdec_session *sess,
}
EXPORT_SYMBOL_GPL(amvdec_set_canvases);
-void amvdec_add_ts(struct amvdec_session *sess, u64 ts,
- struct v4l2_timecode tc, u32 offset, u32 vbuf_flags)
+int amvdec_add_ts(struct amvdec_session *sess, u64 ts,
+ struct v4l2_timecode tc, u32 offset, u32 vbuf_flags)
{
struct amvdec_timestamp *new_ts;
unsigned long flags;
new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL);
+ if (!new_ts)
+ return -ENOMEM;
new_ts->ts = ts;
new_ts->tc = tc;
new_ts->offset = offset;
diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.h b/drivers/staging/media/meson/vdec/vdec_helpers.h
index 88137d15aa3a..4bf3e61d081b 100644
--- a/drivers/staging/media/meson/vdec/vdec_helpers.h
+++ b/drivers/staging/media/meson/vdec/vdec_helpers.h
@@ -56,8 +56,8 @@ void amvdec_dst_buf_done_offset(struct amvdec_session *sess,
* @offset: offset in the VIFIFO where the associated packet was written
* @flags: the vb2_v4l2_buffer flags
*/
-void amvdec_add_ts(struct amvdec_session *sess, u64 ts,
- struct v4l2_timecode tc, u32 offset, u32 flags);
+int amvdec_add_ts(struct amvdec_session *sess, u64 ts,
+ struct v4l2_timecode tc, u32 offset, u32 flags);
void amvdec_remove_ts(struct amvdec_session *sess, u64 ts);
/**
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