| Message ID | 20210309234317.1021588-1-ribalda@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | media: videobuf2: Fix integer overrun in allocation | expand |
On (21/03/10 00:43), Ricardo Ribalda wrote: > The plane_length is an unsigned integer. So, if we have a size of > 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32. Hi Ricardo, > @@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) > * NOTE: mmapped areas should be page aligned > */ > for (plane = 0; plane < vb->num_planes; ++plane) { > + unsigned long size = vb->planes[plane].length; > + > /* Memops alloc requires size to be page aligned. */ > - unsigned long size = PAGE_ALIGN(vb->planes[plane].length); > + size = PAGE_ALIGN(size); > > /* Did it wrap around? */ > if (size < vb->planes[plane].length) Shouldn't the same be done in vb2_mmap()? -ss
Hi Sergey On Wed, Mar 10, 2021 at 2:42 AM Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> wrote: > > On (21/03/10 00:43), Ricardo Ribalda wrote: > > The plane_length is an unsigned integer. So, if we have a size of > > 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32. > > Hi Ricardo, > > > @@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) > > * NOTE: mmapped areas should be page aligned > > */ > > for (plane = 0; plane < vb->num_planes; ++plane) { > > + unsigned long size = vb->planes[plane].length; > > + > > /* Memops alloc requires size to be page aligned. */ > > - unsigned long size = PAGE_ALIGN(vb->planes[plane].length); > > + size = PAGE_ALIGN(size); > > > > /* Did it wrap around? */ > > if (size < vb->planes[plane].length) > > Shouldn't the same be done in vb2_mmap()? Indeed, I was having tunnel vision focussing on my issue. I have sent a new patch. Thanks! > > -ss -- Ricardo Ribalda
On (21/03/10 00:43), Ricardo Ribalda wrote: > > The plane_length is an unsigned integer. So, if we have a size of > 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32. > > Cc: stable@vger.kernel.org > Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap") > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Hi Ricardo, Thank you for the patch. On Wed, Mar 10, 2021 at 12:43:17AM +0100, Ricardo Ribalda wrote: > The plane_length is an unsigned integer. So, if we have a size of > 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32. > > Cc: stable@vger.kernel.org > Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap") > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > --- > drivers/media/common/videobuf2/videobuf2-core.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c > index 02281d13505f..543da515c761 100644 > --- a/drivers/media/common/videobuf2/videobuf2-core.c > +++ b/drivers/media/common/videobuf2/videobuf2-core.c > @@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) > * NOTE: mmapped areas should be page aligned > */ > for (plane = 0; plane < vb->num_planes; ++plane) { > + unsigned long size = vb->planes[plane].length; unsigned long is still 32-bit on 32-bit platforms. > + > /* Memops alloc requires size to be page aligned. */ > - unsigned long size = PAGE_ALIGN(vb->planes[plane].length); > + size = PAGE_ALIGN(size); > > /* Did it wrap around? */ > if (size < vb->planes[plane].length) Doesn't this address the issue already ? -- Regards, Laurent Pinchart
Hi Laurent On Wed, Mar 10, 2021 at 8:49 AM Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > Hi Ricardo, > > Thank you for the patch. Thank you! > > On Wed, Mar 10, 2021 at 12:43:17AM +0100, Ricardo Ribalda wrote: > > The plane_length is an unsigned integer. So, if we have a size of > > 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32. > > > > Cc: stable@vger.kernel.org > > Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap") > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > --- > > drivers/media/common/videobuf2/videobuf2-core.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c > > index 02281d13505f..543da515c761 100644 > > --- a/drivers/media/common/videobuf2/videobuf2-core.c > > +++ b/drivers/media/common/videobuf2/videobuf2-core.c > > @@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) > > * NOTE: mmapped areas should be page aligned > > */ > > for (plane = 0; plane < vb->num_planes; ++plane) { > > + unsigned long size = vb->planes[plane].length; > > unsigned long is still 32-bit on 32-bit platforms. > > > + > > /* Memops alloc requires size to be page aligned. */ > > - unsigned long size = PAGE_ALIGN(vb->planes[plane].length); > > + size = PAGE_ALIGN(size); > > > > /* Did it wrap around? */ > > if (size < vb->planes[plane].length) > > Doesn't this address the issue already ? Yes and no. If you need to allocate 0xffffffff you are still affected by the underrun. The core will return an error instead of doing the allocation. (yes, I know it is a lot of memory for a buffer) > > > -- > Regards, > > Laurent Pinchart -- Ricardo Ribalda
Hi Ricardo, On Wed, Mar 10, 2021 at 08:58:39AM +0100, Ricardo Ribalda wrote: > On Wed, Mar 10, 2021 at 8:49 AM Laurent Pinchart wrote: > > On Wed, Mar 10, 2021 at 12:43:17AM +0100, Ricardo Ribalda wrote: > > > The plane_length is an unsigned integer. So, if we have a size of > > > 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32. > > > > > > Cc: stable@vger.kernel.org > > > Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap") > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > > --- > > > drivers/media/common/videobuf2/videobuf2-core.c | 4 +++- > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c > > > index 02281d13505f..543da515c761 100644 > > > --- a/drivers/media/common/videobuf2/videobuf2-core.c > > > +++ b/drivers/media/common/videobuf2/videobuf2-core.c > > > @@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) > > > * NOTE: mmapped areas should be page aligned > > > */ > > > for (plane = 0; plane < vb->num_planes; ++plane) { > > > + unsigned long size = vb->planes[plane].length; > > > > unsigned long is still 32-bit on 32-bit platforms. > > > > > + > > > /* Memops alloc requires size to be page aligned. */ > > > - unsigned long size = PAGE_ALIGN(vb->planes[plane].length); > > > + size = PAGE_ALIGN(size); > > > > > > /* Did it wrap around? */ > > > if (size < vb->planes[plane].length) > > > > Doesn't this address the issue already ? > > Yes and no. If you need to allocate 0xffffffff you are still affected > by the underrun. The core will return an error instead of doing the > allocation. > > (yes, I know it is a lot of memory for a buffer) That's my point, I don't think there's a need for this :-) Especially with v4l2_buffer.m.offset being a __u32, we are limited to 4GB for *all* buffers. -- Regards, Laurent Pinchart
Hi Laurent On Wed, Mar 10, 2021 at 9:12 AM Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > Hi Ricardo, > > On Wed, Mar 10, 2021 at 08:58:39AM +0100, Ricardo Ribalda wrote: > > On Wed, Mar 10, 2021 at 8:49 AM Laurent Pinchart wrote: > > > On Wed, Mar 10, 2021 at 12:43:17AM +0100, Ricardo Ribalda wrote: > > > > The plane_length is an unsigned integer. So, if we have a size of > > > > 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32. > > > > > > > > Cc: stable@vger.kernel.org > > > > Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap") > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > > > --- > > > > drivers/media/common/videobuf2/videobuf2-core.c | 4 +++- > > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c > > > > index 02281d13505f..543da515c761 100644 > > > > --- a/drivers/media/common/videobuf2/videobuf2-core.c > > > > +++ b/drivers/media/common/videobuf2/videobuf2-core.c > > > > @@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) > > > > * NOTE: mmapped areas should be page aligned > > > > */ > > > > for (plane = 0; plane < vb->num_planes; ++plane) { > > > > + unsigned long size = vb->planes[plane].length; > > > > > > unsigned long is still 32-bit on 32-bit platforms. > > > > > > > + > > > > /* Memops alloc requires size to be page aligned. */ > > > > - unsigned long size = PAGE_ALIGN(vb->planes[plane].length); > > > > + size = PAGE_ALIGN(size); > > > > > > > > /* Did it wrap around? */ > > > > if (size < vb->planes[plane].length) > > > > > > Doesn't this address the issue already ? > > > > Yes and no. If you need to allocate 0xffffffff you are still affected > > by the underrun. The core will return an error instead of doing the > > allocation. > > > > (yes, I know it is a lot of memory for a buffer) > > That's my point, I don't think there's a need for this :-) Especially > with v4l2_buffer.m.offset being a __u32, we are limited to 4GB for *all* > buffers. I guess I will convert this patch into a documentation patch, so we explicitly know the limit of the API (1<<32 - PAGE_SIZE). Thanks! > > -- > Regards, > > Laurent Pinchart
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index 02281d13505f..543da515c761 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) * NOTE: mmapped areas should be page aligned */ for (plane = 0; plane < vb->num_planes; ++plane) { + unsigned long size = vb->planes[plane].length; + /* Memops alloc requires size to be page aligned. */ - unsigned long size = PAGE_ALIGN(vb->planes[plane].length); + size = PAGE_ALIGN(size); /* Did it wrap around? */ if (size < vb->planes[plane].length)
The plane_length is an unsigned integer. So, if we have a size of 0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32. Cc: stable@vger.kernel.org Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap") Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> --- drivers/media/common/videobuf2/videobuf2-core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)