mirror_zfs/module/icp/algs/modes/modes.c
Richard Yao c77d2d7415 crypto_get_ptrs() should always write to *out_data_2
Callers will check if it has been set to NULL before trying to access
it, but never initialize it themselves. Whenever "one block spans two
iovecs", `crypto_get_ptrs()` will return, without ever setting
`*out_data_2 = NULL`. The caller will then do a NULL check against the
uninitailized pointer and if it is not zero, pass it to `memcpy()`.

The only reason this has not caused horrible runtime issues is because
`memcpy()` should be told to copy zero bytes when this happens. That
said, this is technically undefined behavior, so we should correct it so
that future changes to the code cannot trigger it.

Clang's static analyzer found this with the help of CodeChecker's CTU
analysis.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14043
2022-10-19 17:10:56 -07:00

168 lines
4.3 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <sys/zfs_context.h>
#include <modes/modes.h>
#include <sys/crypto/common.h>
#include <sys/crypto/impl.h>
/*
* Initialize by setting iov_or_mp to point to the current iovec or mp,
* and by setting current_offset to an offset within the current iovec or mp.
*/
void
crypto_init_ptrs(crypto_data_t *out, void **iov_or_mp, offset_t *current_offset)
{
offset_t offset;
switch (out->cd_format) {
case CRYPTO_DATA_RAW:
*current_offset = out->cd_offset;
break;
case CRYPTO_DATA_UIO: {
zfs_uio_t *uiop = out->cd_uio;
uint_t vec_idx;
offset = out->cd_offset;
offset = zfs_uio_index_at_offset(uiop, offset, &vec_idx);
*current_offset = offset;
*iov_or_mp = (void *)(uintptr_t)vec_idx;
break;
}
} /* end switch */
}
/*
* Get pointers for where in the output to copy a block of encrypted or
* decrypted data. The iov_or_mp argument stores a pointer to the current
* iovec or mp, and offset stores an offset into the current iovec or mp.
*/
void
crypto_get_ptrs(crypto_data_t *out, void **iov_or_mp, offset_t *current_offset,
uint8_t **out_data_1, size_t *out_data_1_len, uint8_t **out_data_2,
size_t amt)
{
offset_t offset;
switch (out->cd_format) {
case CRYPTO_DATA_RAW: {
iovec_t *iov;
offset = *current_offset;
iov = &out->cd_raw;
if ((offset + amt) <= iov->iov_len) {
/* one block fits */
*out_data_1 = (uint8_t *)iov->iov_base + offset;
*out_data_1_len = amt;
*out_data_2 = NULL;
*current_offset = offset + amt;
}
break;
}
case CRYPTO_DATA_UIO: {
zfs_uio_t *uio = out->cd_uio;
offset_t offset;
uint_t vec_idx;
uint8_t *p;
uint64_t iov_len;
void *iov_base;
offset = *current_offset;
vec_idx = (uintptr_t)(*iov_or_mp);
zfs_uio_iov_at_index(uio, vec_idx, &iov_base, &iov_len);
p = (uint8_t *)iov_base + offset;
*out_data_1 = p;
if (offset + amt <= iov_len) {
/* can fit one block into this iov */
*out_data_1_len = amt;
*out_data_2 = NULL;
*current_offset = offset + amt;
} else {
/* one block spans two iovecs */
*out_data_1_len = iov_len - offset;
if (vec_idx == zfs_uio_iovcnt(uio)) {
*out_data_2 = NULL;
return;
}
vec_idx++;
zfs_uio_iov_at_index(uio, vec_idx, &iov_base, &iov_len);
*out_data_2 = (uint8_t *)iov_base;
*current_offset = amt - *out_data_1_len;
}
*iov_or_mp = (void *)(uintptr_t)vec_idx;
break;
}
} /* end switch */
}
void
crypto_free_mode_ctx(void *ctx)
{
common_ctx_t *common_ctx = (common_ctx_t *)ctx;
switch (common_ctx->cc_flags &
(ECB_MODE|CBC_MODE|CTR_MODE|CCM_MODE|GCM_MODE|GMAC_MODE)) {
case ECB_MODE:
kmem_free(common_ctx, sizeof (ecb_ctx_t));
break;
case CBC_MODE:
kmem_free(common_ctx, sizeof (cbc_ctx_t));
break;
case CTR_MODE:
kmem_free(common_ctx, sizeof (ctr_ctx_t));
break;
case CCM_MODE:
if (((ccm_ctx_t *)ctx)->ccm_pt_buf != NULL)
vmem_free(((ccm_ctx_t *)ctx)->ccm_pt_buf,
((ccm_ctx_t *)ctx)->ccm_data_len);
kmem_free(ctx, sizeof (ccm_ctx_t));
break;
case GCM_MODE:
case GMAC_MODE:
if (((gcm_ctx_t *)ctx)->gcm_pt_buf != NULL)
vmem_free(((gcm_ctx_t *)ctx)->gcm_pt_buf,
((gcm_ctx_t *)ctx)->gcm_pt_buf_len);
#ifdef CAN_USE_GCM_ASM
if (((gcm_ctx_t *)ctx)->gcm_Htable != NULL) {
gcm_ctx_t *gcm_ctx = (gcm_ctx_t *)ctx;
memset(gcm_ctx->gcm_Htable, 0, gcm_ctx->gcm_htab_len);
kmem_free(gcm_ctx->gcm_Htable, gcm_ctx->gcm_htab_len);
}
#endif
kmem_free(ctx, sizeof (gcm_ctx_t));
}
}