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 via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).
While there, use struct_size() helper, instead of the open-coded version, to calculate the size for the allocation of the whole flexible structure, including of course, the flexible-array member.
This code was found with the help of Coccinelle, and audited and fixed manually.
Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org --- drivers/soc/qcom/apr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/soc/qcom/apr.c b/drivers/soc/qcom/apr.c index 30f81d6d9d9d..1f8b315576a4 100644 --- a/drivers/soc/qcom/apr.c +++ b/drivers/soc/qcom/apr.c @@ -41,7 +41,7 @@ struct packet_router { struct apr_rx_buf { struct list_head node; int len; - uint8_t buf[]; + uint8_t buf[] __counted_by(len); };
/** @@ -171,7 +171,7 @@ static int apr_callback(struct rpmsg_device *rpdev, void *buf, return -EINVAL; }
- abuf = kzalloc(sizeof(*abuf) + len, GFP_ATOMIC); + abuf = kzalloc(struct_size(abuf, buf, len), GFP_ATOMIC); if (!abuf) return -ENOMEM;