fix(el3-spmc): fix coverity scan warnings
Validate emad descriptor integrity before accessing.
Check for NULL pointer access.
Signed-off-by: Shruti Gupta <shruti.gupta@arm.com>
Change-Id: Id4ff3e5d88be95ca8d067378e344947880ec984b
diff --git a/services/std_svc/spm/el3_spmc/spmc_shared_mem.c b/services/std_svc/spm/el3_spmc/spmc_shared_mem.c
index bf3fb28..c039350 100644
--- a/services/std_svc/spm/el3_spmc/spmc_shared_mem.c
+++ b/services/std_svc/spm/el3_spmc/spmc_shared_mem.c
@@ -274,13 +274,15 @@
* spmc_shmem_obj_validate_id - Validate a partition ID is participating in
* a given memory transaction.
* @sp_id: Partition ID to validate.
- * @desc: Descriptor of the memory transaction.
- *
+ * @obj: The shared memory object containing the descriptor
+ * of the memory transaction.
* Return: true if ID is valid, else false.
*/
-bool spmc_shmem_obj_validate_id(const struct ffa_mtd *desc, uint16_t sp_id)
+bool spmc_shmem_obj_validate_id(struct spmc_shmem_obj *obj, uint16_t sp_id)
{
bool found = false;
+ struct ffa_mtd *desc = &obj->desc;
+ size_t desc_size = obj->desc_size;
/* Validate the partition is a valid participant. */
for (unsigned int i = 0U; i < desc->emad_count; i++) {
@@ -290,6 +292,15 @@
emad = spmc_shmem_obj_get_emad(desc, i,
MAKE_FFA_VERSION(1, 1),
&emad_size);
+ /*
+ * Validate the calculated emad address resides within the
+ * descriptor.
+ */
+ if ((emad == NULL) || (uintptr_t) emad >=
+ (uintptr_t)((uint8_t *) desc + desc_size)) {
+ VERBOSE("Invalid emad.\n");
+ break;
+ }
if (sp_id == emad->mapd.endpoint_id) {
found = true;
break;
@@ -477,6 +488,12 @@
/* Copy across the emad structs. */
for (unsigned int i = 0U; i < out->emad_count; i++) {
+ /* Bound check for emad array. */
+ if (((uint8_t *)emad_array_in + sizeof(struct ffa_emad_v1_0)) >
+ ((uint8_t *) mtd_orig + orig->desc_size)) {
+ VERBOSE("%s: Invalid mtd structure.\n", __func__);
+ return false;
+ }
memcpy(&emad_array_out[i], &emad_array_in[i],
sizeof(struct ffa_emad_v1_0));
}
@@ -544,6 +561,7 @@
size_t mrd_out_offset;
size_t emad_out_array_size;
size_t mrd_size = 0;
+ size_t orig_desc_size = orig->desc_size;
/* Populate the v1.0 descriptor format from the v1.1 struct. */
out->sender_id = mtd_orig->sender_id;
@@ -561,6 +579,12 @@
/* Copy across the emad structs. */
emad_in = emad_array_in;
for (unsigned int i = 0U; i < out->emad_count; i++) {
+ /* Bound check for emad array. */
+ if (((uint8_t *)emad_in + sizeof(struct ffa_emad_v1_0)) >
+ ((uint8_t *) mtd_orig + orig_desc_size)) {
+ VERBOSE("%s: Invalid mtd structure.\n", __func__);
+ return false;
+ }
memcpy(&emad_array_out[i], emad_in,
sizeof(struct ffa_emad_v1_0));
@@ -1444,7 +1468,7 @@
}
/* Validate the caller is a valid participant. */
- if (!spmc_shmem_obj_validate_id(&obj->desc, sp_ctx->sp_id)) {
+ if (!spmc_shmem_obj_validate_id(obj, sp_ctx->sp_id)) {
WARN("%s: Invalid endpoint ID (0x%x).\n",
__func__, sp_ctx->sp_id);
ret = FFA_ERROR_INVALID_PARAMETER;
@@ -1763,7 +1787,7 @@
}
/* Validate the caller is a valid participant. */
- if (!spmc_shmem_obj_validate_id(&obj->desc, sp_ctx->sp_id)) {
+ if (!spmc_shmem_obj_validate_id(obj, sp_ctx->sp_id)) {
WARN("%s: Invalid endpoint ID (0x%x).\n",
__func__, req->endpoint_array[0]);
ret = FFA_ERROR_INVALID_PARAMETER;