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| author | Kees Cook <keescook@chromium.org> | 2023-09-22 10:49:52 -0700 |
|---|---|---|
| committer | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2023-10-07 10:55:45 +0200 |
| commit | 54b6b605b9a00f5d93b48734122fa87ae345981e (patch) | |
| tree | 783f38bbdc3bf3d30fd431362219b50eda374852 | |
| parent | d425557814ab039012294aa6fd7dc0dd7f3ac4e3 (diff) | |
| download | lwn-54b6b605b9a00f5d93b48734122fa87ae345981e.tar.gz lwn-54b6b605b9a00f5d93b48734122fa87ae345981e.zip | |
media: v4l2-event: Annotate struct v4l2_subscribed_event with __counted_by
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
As found with Coccinelle[1], add __counted_by for
struct v4l2_subscribed_event.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.
[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
Cc: lijian <lijian@yulong.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-event.c | 2 | ||||
| -rw-r--r-- | include/media/v4l2-event.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/media/v4l2-core/v4l2-event.c b/drivers/media/v4l2-core/v4l2-event.c index c5ce9f11ad7b..3898ff7edddb 100644 --- a/drivers/media/v4l2-core/v4l2-event.c +++ b/drivers/media/v4l2-core/v4l2-event.c @@ -238,6 +238,7 @@ int v4l2_event_subscribe(struct v4l2_fh *fh, sev = kvzalloc(struct_size(sev, events, elems), GFP_KERNEL); if (!sev) return -ENOMEM; + sev->elems = elems; for (i = 0; i < elems; i++) sev->events[i].sev = sev; sev->type = sub->type; @@ -245,7 +246,6 @@ int v4l2_event_subscribe(struct v4l2_fh *fh, sev->flags = sub->flags; sev->fh = fh; sev->ops = ops; - sev->elems = elems; mutex_lock(&fh->subscribe_lock); diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h index 4ffa914ade3a..3a0e2588361c 100644 --- a/include/media/v4l2-event.h +++ b/include/media/v4l2-event.h @@ -78,7 +78,7 @@ struct v4l2_subscribed_event { unsigned int elems; unsigned int first; unsigned int in_use; - struct v4l2_kevent events[]; + struct v4l2_kevent events[] __counted_by(elems); }; /** |