llext: load: memcpy section header

When loading from `.elf` files, it is not guaranteed that section
headers are word aligned with the `.elf` file. Attempting to perform
a direct assignment results in the compiler assuming the input pointer
is aligned, resulting in usage faults if the assumption is broken.

Signed-off-by: Jordan Yates <[email protected]>

Author: JordanYates

subsys/llext/llext_load.c

@@ -177,24 +177,24 @@ static int llext_find_tables(struct llext_loader *ldr, struct llext *ext)
 
 		if (shdr->sh_type == SHT_SYMTAB && ldr->hdr.e_type == ET_REL) {
 			LOG_DBG("symtab at %d", i);
-			ldr->sects[LLEXT_MEM_SYMTAB] = *shdr;
+			memcpy(&ldr->sects[LLEXT_MEM_SYMTAB], shdr, sizeof(*shdr));
 			ldr->sect_map[i].mem_idx = LLEXT_MEM_SYMTAB;
 			strtab_ndx = shdr->sh_link;
 			table_cnt++;
 		} else if (shdr->sh_type == SHT_DYNSYM && ldr->hdr.e_type == ET_DYN) {
 			LOG_DBG("dynsym at %d", i);
-			ldr->sects[LLEXT_MEM_SYMTAB] = *shdr;
+			memcpy(&ldr->sects[LLEXT_MEM_SYMTAB], shdr, sizeof(*shdr));
 			ldr->sect_map[i].mem_idx = LLEXT_MEM_SYMTAB;
 			strtab_ndx = shdr->sh_link;
 			table_cnt++;
 		} else if (shdr->sh_type == SHT_STRTAB && i == shstrtab_ndx) {
 			LOG_DBG("shstrtab at %d", i);
-			ldr->sects[LLEXT_MEM_SHSTRTAB] = *shdr;
+			memcpy(&ldr->sects[LLEXT_MEM_SHSTRTAB], shdr, sizeof(*shdr));
 			ldr->sect_map[i].mem_idx = LLEXT_MEM_SHSTRTAB;
 			table_cnt++;
 		} else if (shdr->sh_type == SHT_STRTAB && i == strtab_ndx) {
 			LOG_DBG("strtab at %d", i);
-			ldr->sects[LLEXT_MEM_STRTAB] = *shdr;
+			memcpy(&ldr->sects[LLEXT_MEM_STRTAB], shdr, sizeof(*shdr));
 			ldr->sect_map[i].mem_idx = LLEXT_MEM_STRTAB;
 			table_cnt++;
 		}