| Message ID | 20230204183804.never.323-kees@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: imx-jpeg: Bounds check sizeimage access | expand |
diff --git a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c index 6cd015a35f7c..ac44bf23953a 100644 --- a/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c +++ b/drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c @@ -637,6 +637,11 @@ static u32 mxc_jpeg_get_plane_size(struct mxc_jpeg_q_data *q_data, u32 plane_no) return q_data->sizeimage[plane_no]; size = q_data->sizeimage[fmt->mem_planes - 1]; + + /* Should be impossible given mxc_formats. */ + if (WARN_ON_ONCE(fmt->comp_planes > ARRAY_SIZE(q_data->sizeimage))) + return size; + for (i = fmt->mem_planes; i < fmt->comp_planes; i++) size += q_data->sizeimage[i];
The call of mxc_jpeg_get_plane_size() from mxc_jpeg_dec_irq() sets plane_no argument to 1. The compiler sees that it's possible to end up with an access beyond the bounds of sizeimage, if mem_planes was too large: if (plane_no >= fmt->mem_planes) // mem_planes = 2+ return 0; if (fmt->mem_planes == fmt->comp_planes) // comp_planes != mem_planes return q_data->sizeimage[plane_no]; if (plane_no < fmt->mem_planes - 1) // mem_planes = 2 return q_data->sizeimage[plane_no]; comp_planes == 0 or 1 is safe. comp_planes > 2 would be out of bounds. (This isn't currently possible given the contents of mxc_formats, though.) Silence the warning by bounds checking comp_planes for future robustness. Seen with GCC 13: In function 'mxc_jpeg_get_plane_size', inlined from 'mxc_jpeg_dec_irq' at ../drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c:729:14: ../drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c:641:42: warning: array subscript 2 is above array bounds of 'u32[2]' {aka 'unsigned int[2]'} [-Warray-bounds=] 641 | size += q_data->sizeimage[i]; | ~~~~~~~~~~~~~~~~~^~~ In file included from ../drivers/media/platform/nxp/imx-jpeg/mxc-jpeg-hw.h:112, from ../drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c:63: ../drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.h: In function 'mxc_jpeg_dec_irq': ../drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.h:84:41: note: while referencing 'sizeimage' 84 | u32 sizeimage[MXC_JPEG_MAX_PLANES]; | ^~~~~~~~~ Cc: Mirela Rabulea <mirela.rabulea@nxp.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: linux-media@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c | 5 +++++ 1 file changed, 5 insertions(+)