From: Kees Cook <keescook@chromium.org>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Kees Cook <keescook@chromium.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH] media: omap3isp: Use struct_group() for memcpy() region
Date: Thu, 18 Nov 2021 10:43:52 -0800 [thread overview]
Message-ID: <20211118184352.1284792-1-keescook@chromium.org> (raw)
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields. Wrap the target region
in struct_group(). This additionally fixes a theoretical misalignment
of the copy (since the size of "buf" changes between 64-bit and 32-bit,
but this is likely never built for 64-bit).
FWIW, I think this code is totally broken on 64-bit (which appears to
not be a "real" build configuration): it would either always fail (with
an uninitialized data->buf_size) or would cause corruption in userspace
due to the copy_to_user() in the call path against an uninitialized
data->buf value:
omap3isp_stat_request_statistics_time32(...)
struct omap3isp_stat_data data64;
...
omap3isp_stat_request_statistics(stat, &data64);
int omap3isp_stat_request_statistics(struct ispstat *stat,
struct omap3isp_stat_data *data)
...
buf = isp_stat_buf_get(stat, data);
static struct ispstat_buffer *isp_stat_buf_get(struct ispstat *stat,
struct omap3isp_stat_data *data)
...
if (buf->buf_size > data->buf_size) {
...
return ERR_PTR(-EINVAL);
}
...
rval = copy_to_user(data->buf,
buf->virt_addr,
buf->buf_size);
Regardless, additionally initialize data64 to be zero-filled to avoid
undefined behavior.
Fixes: 378e3f81cb56 ("media: omap3isp: support 64-bit version of omap3isp_stat_data")
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/media/platform/omap3isp/ispstat.c | 5 +++--
include/uapi/linux/omap3isp.h | 21 +++++++++++++--------
2 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/drivers/media/platform/omap3isp/ispstat.c b/drivers/media/platform/omap3isp/ispstat.c
index 5b9b57f4d9bf..68cf68dbcace 100644
--- a/drivers/media/platform/omap3isp/ispstat.c
+++ b/drivers/media/platform/omap3isp/ispstat.c
@@ -512,7 +512,7 @@ int omap3isp_stat_request_statistics(struct ispstat *stat,
int omap3isp_stat_request_statistics_time32(struct ispstat *stat,
struct omap3isp_stat_data_time32 *data)
{
- struct omap3isp_stat_data data64;
+ struct omap3isp_stat_data data64 = { };
int ret;
ret = omap3isp_stat_request_statistics(stat, &data64);
@@ -521,7 +521,8 @@ int omap3isp_stat_request_statistics_time32(struct ispstat *stat,
data->ts.tv_sec = data64.ts.tv_sec;
data->ts.tv_usec = data64.ts.tv_usec;
- memcpy(&data->buf, &data64.buf, sizeof(*data) - sizeof(data->ts));
+ data->buf = (uintptr_t)data64.buf;
+ memcpy(&data->frame, &data64.frame, sizeof(data->frame));
return 0;
}
diff --git a/include/uapi/linux/omap3isp.h b/include/uapi/linux/omap3isp.h
index 87b55755f4ff..9a6b3ed11455 100644
--- a/include/uapi/linux/omap3isp.h
+++ b/include/uapi/linux/omap3isp.h
@@ -162,6 +162,7 @@ struct omap3isp_h3a_aewb_config {
* struct omap3isp_stat_data - Statistic data sent to or received from user
* @ts: Timestamp of returned framestats.
* @buf: Pointer to pass to user.
+ * @buf_size: Size of buffer.
* @frame_number: Frame number of requested stats.
* @cur_frame: Current frame number being processed.
* @config_counter: Number of the configuration associated with the data.
@@ -176,10 +177,12 @@ struct omap3isp_stat_data {
struct timeval ts;
#endif
void __user *buf;
- __u32 buf_size;
- __u16 frame_number;
- __u16 cur_frame;
- __u16 config_counter;
+ __struct_group(/* no type */, frame, /* no attrs */,
+ __u32 buf_size;
+ __u16 frame_number;
+ __u16 cur_frame;
+ __u16 config_counter;
+ );
};
#ifdef __KERNEL__
@@ -189,10 +192,12 @@ struct omap3isp_stat_data_time32 {
__s32 tv_usec;
} ts;
__u32 buf;
- __u32 buf_size;
- __u16 frame_number;
- __u16 cur_frame;
- __u16 config_counter;
+ __struct_group(/* no type */, frame, /* no attrs */,
+ __u32 buf_size;
+ __u16 frame_number;
+ __u16 cur_frame;
+ __u16 config_counter;
+ );
};
#endif
--
2.30.2
next reply other threads:[~2021-11-18 18:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-18 18:43 Kees Cook [this message]
2021-12-13 23:24 ` [PATCH] media: omap3isp: Use struct_group() for memcpy() region Gustavo A. R. Silva
2021-12-15 17:38 ` Kees Cook
2021-12-15 22:05 ` Gustavo A. R. Silva
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