@@ -263,7 +263,7 @@ acpi_ut_execute_CID(struct acpi_namespace_node *device_node,
* 3) Size of the actual CID strings
*/
cid_list_size = sizeof(struct acpi_pnp_device_id_list) +
- ((count - 1) * sizeof(struct acpi_pnp_device_id)) +
+ count * sizeof(struct acpi_pnp_device_id) +
string_area_size;
cid_list = ACPI_ALLOCATE_ZEROED(cid_list_size);
@@ -1145,7 +1145,7 @@ struct acpi_pnp_device_id {
struct acpi_pnp_device_id_list {
u32 count; /* Number of IDs in Ids array */
u32 list_size; /* Size of list, including ID strings */
- struct acpi_pnp_device_id ids[1]; /* ID array */
+ struct acpi_pnp_device_id ids[]; /* ID array */
};
/*
The current codebase makes use of one-element arrays in the following form: struct something { int length; u8 data[1]; }; struct something *instance; instance = kmalloc(sizeof(*instance) + size, GFP_KERNEL); instance->length = size; memcpy(instance->data, source, size); but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle and audited _manually_. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- Changes in v2: - Don't use struct_size() for now. - Update subject line and changelog text. drivers/acpi/acpica/utids.c | 2 +- include/acpi/actypes.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)