[PATCH][next] soc: qcom: apr: Add __counted_by for struct apr_rx_buf and use struct_size()
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;
On Mon, Oct 09, 2023 at 03:30:17PM -0600, Gustavo A. R. Silva 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 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
Yup, looks right.
Reviewed-by: Kees Cook keescook@chromium.org
On Mon, Oct 9, 2023 at 2:30 PM Gustavo A. R. Silva gustavoars@kernel.org 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 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
Excited for __counted_by to land! This looks right.
Reviewed-by: Justin Stitt justinstitt@google.com
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;-- 2.34.1
On Mon, Oct 09, 2023 at 03:30:17PM -0600, Gustavo A. R. Silva 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 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
Applied, thanks.
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;
-- 2.34.1
participants (4)
-
Bjorn Andersson -
Gustavo A. R. Silva -
Justin Stitt -
Kees Cook