From: Gustavo A. R. Silva Date: Mon, 9 Oct 2023 21:24:23 +0000 (-0600) Subject: ASoC: sigmadsp: Add __counted_by for struct sigmadsp_data and use struct_size() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4f88c72b2479cca4a0d4de89b4cbb6f1b37ee96d;p=linux.git ASoC: sigmadsp: Add __counted_by for struct sigmadsp_data 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() 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" Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/ZSRvh1j2MVVhuOUv@work Signed-off-by: Mark Brown --- diff --git a/sound/soc/codecs/sigmadsp.c b/sound/soc/codecs/sigmadsp.c index b93c078a80408..56546e2394aba 100644 --- a/sound/soc/codecs/sigmadsp.c +++ b/sound/soc/codecs/sigmadsp.c @@ -43,7 +43,7 @@ struct sigmadsp_data { uint32_t samplerates; unsigned int addr; unsigned int length; - uint8_t data[]; + uint8_t data[] __counted_by(length); }; struct sigma_fw_chunk { @@ -270,7 +270,7 @@ static int sigma_fw_load_data(struct sigmadsp *sigmadsp, length -= sizeof(*data_chunk); - data = kzalloc(sizeof(*data) + length, GFP_KERNEL); + data = kzalloc(struct_size(data, data, length), GFP_KERNEL); if (!data) return -ENOMEM; @@ -413,7 +413,8 @@ static int process_sigma_action(struct sigmadsp *sigmadsp, 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;