In the quest to remove all stack VLA usage from the kernel[1], this uses the upper bound for the stack buffer. Also adds a sanity check. This additionally raises the stack size limit during the build, to avoid a compiler warning while keeping it reasonably close to expected stack size. The warning was just exposing the existing max stack size, so there is nothing new here; now that it is not hidden in a VLA, the compiler can see how large it might get. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- drivers/crypto/qat/qat_common/Makefile | 2 ++ drivers/crypto/qat/qat_common/qat_algs.c | 8 ++++++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/crypto/qat/qat_common/Makefile b/drivers/crypto/qat/qat_common/Makefile index 47a8e3d8b81a..c2a042023dde 100644 --- a/drivers/crypto/qat/qat_common/Makefile +++ b/drivers/crypto/qat/qat_common/Makefile @@ -19,3 +19,5 @@ intel_qat-objs := adf_cfg.o \ intel_qat-$(CONFIG_DEBUG_FS) += adf_transport_debug.o intel_qat-$(CONFIG_PCI_IOV) += adf_sriov.o adf_pf2vf_msg.o \ adf_vf2pf_msg.o adf_vf_isr.o + +CFLAGS_qat_algs.o := $(call cc-option,-Wframe-larger-than=2300) diff --git a/drivers/crypto/qat/qat_common/qat_algs.c b/drivers/crypto/qat/qat_common/qat_algs.c index 1138e41d6805..257269126601 100644 --- a/drivers/crypto/qat/qat_common/qat_algs.c +++ b/drivers/crypto/qat/qat_common/qat_algs.c @@ -153,8 +153,8 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash, struct sha512_state sha512; int block_size = crypto_shash_blocksize(ctx->hash_tfm); int digest_size = crypto_shash_digestsize(ctx->hash_tfm); - char ipad[block_size]; - char opad[block_size]; + char ipad[CRYPTO_ALG_MAX_BLOCKSIZE]; + char opad[CRYPTO_ALG_MAX_BLOCKSIZE]; __be32 *hash_state_out; __be64 *hash512_state_out; int i, offset; @@ -164,6 +164,10 @@ static int qat_alg_do_precomputes(struct icp_qat_hw_auth_algo_blk *hash, shash->tfm = ctx->hash_tfm; shash->flags = 0x0; + if (WARN_ON(block_size > sizeof(ipad) || + sizeof(ipad) != sizeof(opad))) + return -EINVAL; + if (auth_keylen > block_size) { int ret = crypto_shash_digest(shash, auth_key, auth_keylen, ipad); -- 2.17.1
