LinuxLists.cc - [PATCH] media: mediatek: vcodec: Fix potential array out-of-bounds in decoder queue

2023-03-28 10:11:14

Subject: [PATCH] media: mediatek: vcodec: Fix potential array out-of-bounds in decoder queue_setup

variable *nplanes is provided by user via system call argument. The
possible value of q_data->fmt->num_planes is 1-3, while the value
of *nplanes can be 1-8. The array access by index i can cause array
out-of-bounds.

Fix this bug by checking *nplanes against the array size.

Signed-off-by: Wei Chen <[email protected]>
---
drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
index 641f533c417f..cae34cc7c807 100644
--- a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
+++ b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
@@ -753,6 +753,13 @@ int vb2ops_vdec_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
}

if (*nplanes) {
+ if (vq->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
+ if (*nplanes != q_data->fmt->num_planes)
+ return -EINVAL;
+ else
+ if (*nplanes != 1)
+ return -EINVAL;
+
for (i = 0; i < *nplanes; i++) {
if (sizes[i] < q_data->sizeimage[i])
return -EINVAL;
--
2.25.1

2023-03-28 13:30:49

by kernel test robot

[permalink] [raw]

Subject: Re: [PATCH] media: mediatek: vcodec: Fix potential array out-of-bounds in decoder queue_setup

2023-03-28 17:49:38

by kernel test robot

[permalink] [raw]

Subject: Re: [PATCH] media: mediatek: vcodec: Fix potential array out-of-bounds in decoder queue_setup

Hi Wei,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on media-tree/master]
[also build test WARNING on linus/master v6.3-rc4 next-20230328]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Wei-Chen/media-mediatek-vcodec-Fix-potential-array-out-of-bounds-in-decoder-queue_setup/20230328-181142
base: git://linuxtv.org/media_tree.git master
patch link: https://lore.kernel.org/r/20230328100951.536955-1-harperchen1110%40gmail.com
patch subject: [PATCH] media: mediatek: vcodec: Fix potential array out-of-bounds in decoder queue_setup
config: s390-randconfig-r044-20230327 (https://download.01.org/0day-ci/archive/20230329/[email protected]/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 67409911353323ca5edf2049ef0df54132fa1ca7)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install s390 cross compiling tool for clang build
# apt-get install binutils-s390x-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/caa43627286fb5f3b0b3af7e01e1baeca5c5f9cc
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Wei-Chen/media-mediatek-vcodec-Fix-potential-array-out-of-bounds-in-decoder-queue_setup/20230328-181142
git checkout caa43627286fb5f3b0b3af7e01e1baeca5c5f9cc
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/media/platform/mediatek/vcodec/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <[email protected]>
| Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All warnings (new ones prefixed by >>):

In file included from drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c:9:
In file included from include/media/v4l2-mem2mem.h:16:
In file included from include/media/videobuf2-v4l2.h:16:
In file included from include/media/videobuf2-core.h:18:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:13:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
^
include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
#define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
^
In file included from drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c:9:
In file included from include/media/v4l2-mem2mem.h:16:
In file included from include/media/videobuf2-v4l2.h:16:
In file included from include/media/videobuf2-core.h:18:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:13:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
#define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
^
In file included from drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c:9:
In file included from include/media/v4l2-mem2mem.h:16:
In file included from include/media/videobuf2-v4l2.h:16:
In file included from include/media/videobuf2-core.h:18:
In file included from include/linux/dma-buf.h:16:
In file included from include/linux/iosys-map.h:10:
In file included from include/linux/io.h:13:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
>> drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c:759:3: warning: add explicit braces to avoid dangling else [-Wdangling-else]
else
^
13 warnings generated.

vim +759 drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c

739
740 int vb2ops_vdec_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
741 unsigned int *nplanes, unsigned int sizes[],
742 struct device *alloc_devs[])
743 {
744 struct mtk_vcodec_ctx *ctx = vb2_get_drv_priv(vq);
745 struct mtk_q_data *q_data;
746 unsigned int i;
747
748 q_data = mtk_vdec_get_q_data(ctx, vq->type);
749
750 if (q_data == NULL) {
751 mtk_v4l2_err("vq->type=%d err\n", vq->type);
752 return -EINVAL;
753 }
754
755 if (*nplanes) {
756 if (vq->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
757 if (*nplanes != q_data->fmt->num_planes)
758 return -EINVAL;
> 759 else
760 if (*nplanes != 1)
761 return -EINVAL;
762
763 for (i = 0; i < *nplanes; i++) {
764 if (sizes[i] < q_data->sizeimage[i])
765 return -EINVAL;
766 }
767 } else {
768 if (vq->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
769 *nplanes = q_data->fmt->num_planes;
770 else
771 *nplanes = 1;
772
773 for (i = 0; i < *nplanes; i++)
774 sizes[i] = q_data->sizeimage[i];
775 }
776
777 mtk_v4l2_debug(1,
778 "[%d]\t type = %d, get %d plane(s), %d buffer(s) of size 0x%x 0x%x ",
779 ctx->id, vq->type, *nplanes, *nbuffers,
780 sizes[0], sizes[1]);
781
782 return 0;
783 }
784

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

2023-03-28 18:31:45

by kernel test robot

[permalink] [raw]

Subject: Re: [PATCH] media: mediatek: vcodec: Fix potential array out-of-bounds in decoder queue_setup

2023-03-31 15:29:12

by Nicolas Dufresne

[permalink] [raw]

Subject: Re: [PATCH] media: mediatek: vcodec: Fix potential array out-of-bounds in decoder queue_setup

Hi,

Le mardi 28 mars 2023 à 10:09 +0000, Wei Chen a écrit :
> variable *nplanes is provided by user via system call argument. The
> possible value of q_data->fmt->num_planes is 1-3, while the value
> of *nplanes can be 1-8. The array access by index i can cause array
> out-of-bounds.
>
> Fix this bug by checking *nplanes against the array size.
>
> Signed-off-by: Wei Chen <[email protected]>
> ---
> drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
> index 641f533c417f..cae34cc7c807 100644
> --- a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
> +++ b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
> @@ -753,6 +753,13 @@ int vb2ops_vdec_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
> }
>
> if (*nplanes) {
> + if (vq->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> + if (*nplanes != q_data->fmt->num_planes)
> + return -EINVAL;
> + else
> + if (*nplanes != 1)
> + return -EINVAL;
> +
> for (i = 0; i < *nplanes; i++) {
> if (sizes[i] < q_data->sizeimage[i])
> return -EINVAL;

A bit of context, *nplanes is non zero only when called from VIDIOC_CREATE_BUFS.
I think this highlights a bigger problem around the format in
VIDIOC_CREATE_BUFS. The format should be validated through TRY_FMT in some ways,
notably to apply the HW required alignment, but also to avoid having to validate
that lower in the stack.

Nicolas