Commit 0e17ad87 authored by Kees Cook's avatar Kees Cook
Browse files

powerpc: Split memset() to avoid multi-field overflow 



In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Instead of writing across a field boundary with memset(), move the call
to just the array, and an explicit zeroing of the prior field.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Qinglang Miao <miaoqinglang@huawei.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Hulk Robot <hulkci@huawei.com>
Cc: Wang Wensheng <wangwensheng4@huawei.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/lkml/87czqsnmw9.fsf@mpe.ellerman.id.au
parent 3d0107a7

drivers/macintosh/smu.c

+2 −1
Original line number Diff line number Diff line
@@ -848,7 +848,8 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd) 
	cmd->read = cmd->info.devaddr & 0x01;

	switch(cmd->info.type) {

	case SMU_I2C_TRANSFER_SIMPLE:

		memset(&cmd->info.sublen, 0, 4);

		cmd->info.sublen = 0;

		memset(cmd->info.subaddr, 0, sizeof(cmd->info.subaddr));

		break;

	case SMU_I2C_TRANSFER_COMBINED:

		cmd->info.devaddr &= 0xfe;