subsys/llext: Fail if stated symbol size doesn't fit elf_sym_t

edersondisouza · kartben · commit 3f6734034a73 · 2025-09-20T11:10:51.000+02:00
As it avoid unintended overflows.

Signed-off-by: Ederson de Souza &lt;ederson.desouza@intel.com&gt;
diff --git a/subsys/llext/llext_load.c b/subsys/llext/llext_load.c
@@ -207,6 +207,12 @@ static int llext_find_tables(struct llext_loader *ldr, struct llext *ext)
 		return -ENOEXEC;
 	}
 
+	if (ldr->sects[LLEXT_MEM_SYMTAB].sh_entsize != sizeof(elf_sym_t) ||
+	    ldr->sects[LLEXT_MEM_SYMTAB].sh_size % ldr->sects[LLEXT_MEM_SYMTAB].sh_entsize != 0) {
+		LOG_ERR("Invalid symbol table");
+		return -ENOEXEC;
+	}
+
 	return 0;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -207,6 +207,12 @@ static int llext_find_tables(struct llext_loader ldr, struct llext ext)`
`207`	`207`	`return -ENOEXEC;`
`208`	`208`	`}`
`209`	`209`
	`210`	`+ if (ldr->sects[LLEXT_MEM_SYMTAB].sh_entsize != sizeof(elf_sym_t) \|\|`
	`211`	`+ ldr->sects[LLEXT_MEM_SYMTAB].sh_size % ldr->sects[LLEXT_MEM_SYMTAB].sh_entsize != 0) {`
	`212`	`+ LOG_ERR("Invalid symbol table");`
	`213`	`+ return -ENOEXEC;`
	`214`	`+ }`
	`215`	`+`
`210`	`216`	`return 0;`
`211`	`217`	`}`
`212`	`218`