On 9/22/23 11:50, Kees Cook wrote:
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 bcm_vk_wkent. 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: Scott Branden <scott.bran...@broadcom.com> Cc: Broadcom internal kernel review list <bcm-kernel-feedback-l...@broadcom.com> Cc: Arnd Bergmann <a...@arndb.de> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Signed-off-by: Kees Cook <keesc...@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavo...@kernel.org> Thanks -- Gustavo
--- drivers/misc/bcm-vk/bcm_vk_msg.c | 2 +- drivers/misc/bcm-vk/bcm_vk_msg.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.c b/drivers/misc/bcm-vk/bcm_vk_msg.c index e17d81231ea6..1f42d1d5a630 100644 --- a/drivers/misc/bcm-vk/bcm_vk_msg.c +++ b/drivers/misc/bcm-vk/bcm_vk_msg.c @@ -703,12 +703,12 @@ int bcm_vk_send_shutdown_msg(struct bcm_vk *vk, u32 shut_type, entry = kzalloc(struct_size(entry, to_v_msg, 1), GFP_KERNEL); if (!entry) return -ENOMEM; + entry->to_v_blks = 1; /* always 1 block *//* fill up necessary data */entry->to_v_msg[0].function_id = VK_FID_SHUTDOWN; set_q_num(&entry->to_v_msg[0], q_num); set_msg_id(&entry->to_v_msg[0], VK_SIMPLEX_MSG_ID); - entry->to_v_blks = 1; /* always 1 block */entry->to_v_msg[0].cmd = shut_type;entry->to_v_msg[0].arg = pid; diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.h b/drivers/misc/bcm-vk/bcm_vk_msg.h index 56784c8896d8..157495e48f15 100644 --- a/drivers/misc/bcm-vk/bcm_vk_msg.h +++ b/drivers/misc/bcm-vk/bcm_vk_msg.h @@ -116,7 +116,7 @@ struct bcm_vk_wkent { u32 usr_msg_id; u32 to_v_blks; u32 seq_num; - struct vk_msg_blk to_v_msg[]; + struct vk_msg_blk to_v_msg[] __counted_by(to_v_blks); };/* queue stats counters */
