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authorArnd Bergmann <arnd@arndb.de>2018-01-16 16:52:15 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-30 07:47:43 +0200
commit0256494d842b6cfb5e399e86395820cece35e4d2 (patch)
parentfdf0b926460043d0fea69c4167812e985d442494 (diff)
media: s3c-camif: fix out-of-bounds array access
[ Upstream commit a398e043637a4819a0e96467bfecaabf3224dd62 ] While experimenting with older compiler versions, I ran into a warning that no longer shows up on gcc-4.8 or newer: drivers/media/platform/s3c-camif/camif-capture.c: In function '__camif_subdev_try_format': drivers/media/platform/s3c-camif/camif-capture.c:1265:25: error: array subscript is below array bounds This is an off-by-one bug, leading to an access before the start of the array, while newer compilers silently assume this undefined behavior cannot happen and leave the loop at index 0 if no other entry matches. As Sylvester explains, we actually need to ensure that the value is within the range, so this reworks the loop to be easier to parse correctly, and an additional check to fall back on the first format value for any unexpected input. I found an existing gcc bug for it and added a reduced version of the function there. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69249#c3 Fixes: babde1c243b2 ("[media] V4L: Add driver for S3C24XX/S3C64XX SoC series camera interface") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/media/platform/s3c-camif/camif-capture.c b/drivers/media/platform/s3c-camif/camif-capture.c
index df33e720d664..97a52d4574e7 100644
--- a/drivers/media/platform/s3c-camif/camif-capture.c
+++ b/drivers/media/platform/s3c-camif/camif-capture.c
@@ -1280,16 +1280,17 @@ static void __camif_subdev_try_format(struct camif_dev *camif,
const struct s3c_camif_variant *variant = camif->variant;
const struct vp_pix_limits *pix_lim;
- int i = ARRAY_SIZE(camif_mbus_formats);
+ unsigned int i;
/* FIXME: constraints against codec or preview path ? */
pix_lim = &variant->vp_pix_limits[VP_CODEC];
- while (i-- >= 0)
+ for (i = 0; i < ARRAY_SIZE(camif_mbus_formats); i++)
if (camif_mbus_formats[i] == mf->code)
- mf->code = camif_mbus_formats[i];
+ if (i == ARRAY_SIZE(camif_mbus_formats))
+ mf->code = camif_mbus_formats[0];
if (pad == CAMIF_SD_PAD_SINK) {
v4l_bound_align_image(&mf->width, 8, CAMIF_MAX_PIX_WIDTH,