Commit 5cf47dc1 authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Kalle Valo
Browse files

wifi: hostap: Add __counted_by for struct prism2_download_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() 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: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarKalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/ZSRXXvWMMkm7qqRW@work
parent de8dd096

drivers/net/wireless/intersil/hostap/hostap_download.c

+1 −2
Original line number Diff line number Diff line
@@ -732,8 +732,7 @@ static int prism2_download(local_info_t *local, 
		goto out;

	}



	dl = kzalloc(sizeof(*dl) + param->num_areas *

		     sizeof(struct prism2_download_data_area), GFP_KERNEL);

	dl = kzalloc(struct_size(dl, data, param->num_areas), GFP_KERNEL);

	if (dl == NULL) {

		ret = -ENOMEM;

		goto out;

drivers/net/wireless/intersil/hostap/hostap_wlan.h

+1 −1
Original line number Diff line number Diff line
@@ -617,7 +617,7 @@ struct prism2_download_data { 
		u32 addr; /* wlan card address */

		u32 len;

		u8 *data; /* allocated data */

	} data[];

	} data[] __counted_by(num_areas);

};