llext: add a check to llext_manager_mod_find()

Add a check to llext_manager_mod_find() in case scanning the array
reached the last element, that the index indeed is within that
element's range. Return an error otherwise.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

src/include/sof/lib_manager.h

@@ -114,6 +114,7 @@ struct lib_manager_module {
 	struct llext *llext; /* Zephyr loadable extension context */
 	struct llext_buf_loader *ebl; /* Zephyr loadable extension buffer loader */
 	unsigned int n_dependent; /* For auxiliary modules: number of dependents */
+	unsigned int n_mod;
 	bool mapped;
 	bool domain_dp;
 	struct lib_manager_segment_desc segment[LIB_MANAGER_N_SEGMENTS];

src/library_manager/llext_manager.c

@@ -473,6 +473,7 @@ static int llext_manager_link(const char *name,
 	if (ret >= 0) {
 		llext_get_section_info(ldr, *llext, ret, &hdr, NULL, NULL);
 		*mod_manifest = llext_peek(ldr, hdr->sh_offset);
+		mctx->n_mod = hdr->sh_size / sizeof(struct sof_man_module_manifest);
 	}
 
 	return *buildinfo && *mod_manifest ? 0 : -EPROTO;
@@ -533,14 +534,17 @@ static int llext_manager_mod_init(struct lib_manager_mod_ctx *ctx,
 }
 
 /* Find a module context, containing the driver with the supplied index */
-static unsigned int llext_manager_mod_find(const struct lib_manager_mod_ctx *ctx, unsigned int idx)
+static int llext_manager_mod_find(const struct lib_manager_mod_ctx *ctx, unsigned int idx)
 {
 	unsigned int i;
 
 	for (i = 0; i < ctx->n_mod; i++)
 		if (ctx->mod[i].start_idx > idx)
 			break;
 
+	if (i == ctx->n_mod && ctx->mod[i - 1].start_idx + ctx->mod[i - 1].n_mod <= idx)
+		return -ENOENT;
+
 	return i - 1;
 }
 
@@ -562,7 +566,11 @@ static int llext_manager_link_single(uint32_t module_id, const struct sof_man_fw
 		return -EINVAL;
 	}
 
-	unsigned int mod_ctx_idx = llext_manager_mod_find(ctx, entry_index);
+	int mod_ctx_idx = llext_manager_mod_find(ctx, entry_index);
+
+	if (mod_ctx_idx < 0)
+		return mod_ctx_idx;
+
 	struct lib_manager_module *mctx = ctx->mod + mod_ctx_idx;
 	size_t mod_size;
 	int i, inst_idx;
@@ -950,7 +958,11 @@ int llext_manager_add_domain(const uint32_t component_id, struct k_mem_domain *d
 	const uint32_t module_id = IPC4_MOD_ID(component_id);
 	struct lib_manager_mod_ctx *ctx = lib_manager_get_mod_ctx(module_id);
 	const uint32_t entry_index = LIB_MANAGER_GET_MODULE_INDEX(module_id);
-	const unsigned int mod_idx = llext_manager_mod_find(ctx, entry_index);
+	const int mod_idx = llext_manager_mod_find(ctx, entry_index);
+
+	if (mod_idx < 0)
+		return mod_idx;
+
 	struct lib_manager_module *mctx = ctx->mod + mod_idx;
 
 	/* FIXME: handle dependencies */
@@ -1031,7 +1043,11 @@ int llext_manager_rm_domain(const uint32_t component_id, struct k_mem_domain *do
 	const uint32_t module_id = IPC4_MOD_ID(component_id);
 	struct lib_manager_mod_ctx *ctx = lib_manager_get_mod_ctx(module_id);
 	const uint32_t entry_index = LIB_MANAGER_GET_MODULE_INDEX(module_id);
-	const unsigned int mod_idx = llext_manager_mod_find(ctx, entry_index);
+	const int mod_idx = llext_manager_mod_find(ctx, entry_index);
+
+	if (mod_idx < 0)
+		return mod_idx;
+
 	struct lib_manager_module *mctx = ctx->mod + mod_idx;
 
 	return llext_manager_rm_mod_domain(mctx, domain);
@@ -1056,7 +1072,11 @@ int llext_manager_free_module(const uint32_t component_id)
 		return -ENOENT;
 	}
 
-	unsigned int mod_idx = llext_manager_mod_find(ctx, entry_index);
+	int mod_idx = llext_manager_mod_find(ctx, entry_index);
+
+	if (mod_idx < 0)
+		return mod_idx;
+
 	struct lib_manager_module *mctx = ctx->mod + mod_idx;
 
 	/* Protected by IPC serialization */