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() and size_sub() helpers, 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>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/ZSRvh1j2MVVhuOUv@work
Signed-off-by: Mark Brown <broonie@kernel.org>
uint32_t samplerates;
unsigned int addr;
unsigned int length;
- uint8_t data[];
+ uint8_t data[] __counted_by(length);
};
struct sigma_fw_chunk {
length -= sizeof(*data_chunk);
- data = kzalloc(sizeof(*data) + length, GFP_KERNEL);
+ data = kzalloc(struct_size(data, data, length), GFP_KERNEL);
if (!data)
return -ENOMEM;
if (len < 3)
return -EINVAL;
- data = kzalloc(sizeof(*data) + len - 2, GFP_KERNEL);
+ data = kzalloc(struct_size(data, data, size_sub(len, 2)),
+ GFP_KERNEL);
if (!data)
return -ENOMEM;