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| author | harperchen <harperchen1110@gmail.com> | 2023-03-02 13:39:05 +0100 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@kernel.org> | 2023-03-19 22:55:33 +0100 |
| commit | 47e8b73bc35d7c54642f78e498697692f6358996 (patch) | |
| tree | 7cf3c7da143b75e4d156d8fe3c484a24179f3db2 /drivers/media/pci | |
| parent | ffa331d9bf9407655fc4c4d57dcc92ed2868e326 (diff) | |
| download | linux-stable-47e8b73bc35d7c54642f78e498697692f6358996.tar.gz linux-stable-47e8b73bc35d7c54642f78e498697692f6358996.tar.bz2 linux-stable-47e8b73bc35d7c54642f78e498697692f6358996.zip | |
media: cx23885: Fix a null-ptr-deref bug in buffer_prepare() and buffer_finish()
When the driver calls cx23885_risc_buffer() to prepare the buffer, the
function call dma_alloc_coherent may fail, resulting in a empty buffer
risc->cpu. Later when we free the buffer or access the buffer, null ptr
deref is triggered.
This bug is similar to the following one:
https://git.linuxtv.org/media_stage.git/commit/?id=2b064d91440b33fba5b452f2d1b31f13ae911d71.
We believe the bug can be also dynamically triggered from user side.
Similarly, we fix this by checking the return value of cx23885_risc_buffer()
and the value of risc->cpu before buffer free.
Signed-off-by: harperchen <harperchen1110@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Diffstat (limited to 'drivers/media/pci')
| -rw-r--r-- | drivers/media/pci/cx23885/cx23885-core.c | 4 | ||||
| -rw-r--r-- | drivers/media/pci/cx23885/cx23885-video.c | 13 |
2 files changed, 10 insertions, 7 deletions
diff --git a/drivers/media/pci/cx23885/cx23885-core.c b/drivers/media/pci/cx23885/cx23885-core.c index 9232a966bcab..2ce2914576cf 100644 --- a/drivers/media/pci/cx23885/cx23885-core.c +++ b/drivers/media/pci/cx23885/cx23885-core.c @@ -1325,7 +1325,9 @@ void cx23885_free_buffer(struct cx23885_dev *dev, struct cx23885_buffer *buf) { struct cx23885_riscmem *risc = &buf->risc; - dma_free_coherent(&dev->pci->dev, risc->size, risc->cpu, risc->dma); + if (risc->cpu) + dma_free_coherent(&dev->pci->dev, risc->size, risc->cpu, risc->dma); + memset(risc, 0, sizeof(*risc)); } static void cx23885_tsport_reg_dump(struct cx23885_tsport *port) diff --git a/drivers/media/pci/cx23885/cx23885-video.c b/drivers/media/pci/cx23885/cx23885-video.c index 3d03f5e95786..671fc0588e43 100644 --- a/drivers/media/pci/cx23885/cx23885-video.c +++ b/drivers/media/pci/cx23885/cx23885-video.c @@ -342,6 +342,7 @@ static int queue_setup(struct vb2_queue *q, static int buffer_prepare(struct vb2_buffer *vb) { + int ret; struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); struct cx23885_dev *dev = vb->vb2_queue->drv_priv; struct cx23885_buffer *buf = @@ -358,12 +359,12 @@ static int buffer_prepare(struct vb2_buffer *vb) switch (dev->field) { case V4L2_FIELD_TOP: - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, 0, UNSET, buf->bpl, 0, dev->height); break; case V4L2_FIELD_BOTTOM: - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, UNSET, 0, buf->bpl, 0, dev->height); break; @@ -391,21 +392,21 @@ static int buffer_prepare(struct vb2_buffer *vb) line0_offset = 0; line1_offset = buf->bpl; } - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, line0_offset, line1_offset, buf->bpl, buf->bpl, dev->height >> 1); break; case V4L2_FIELD_SEQ_TB: - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, 0, buf->bpl * (dev->height >> 1), buf->bpl, 0, dev->height >> 1); break; case V4L2_FIELD_SEQ_BT: - cx23885_risc_buffer(dev->pci, &buf->risc, + ret = cx23885_risc_buffer(dev->pci, &buf->risc, sgt->sgl, buf->bpl * (dev->height >> 1), 0, buf->bpl, 0, @@ -418,7 +419,7 @@ static int buffer_prepare(struct vb2_buffer *vb) buf, buf->vb.vb2_buf.index, dev->width, dev->height, dev->fmt->depth, dev->fmt->fourcc, (unsigned long)buf->risc.dma); - return 0; + return ret; } static void buffer_finish(struct vb2_buffer *vb) |