--- libsandbox/wrapper-funcs/__wrapper_exec.c	2018-04-02 22:14:38.445664170 +0200
+++ libsandbox/wrapper-funcs/__wrapper_exec.c	2018-04-02 22:15:55.625666491 +0200
@@ -167,7 +167,7 @@
 				char *symname = (void *)(elf + stroff + sym->st_name); \
 				if (ELF##n##_ST_VISIBILITY(sym->st_other) == STV_DEFAULT && \
 				    sym->st_shndx != SHN_UNDEF && sym->st_shndx < SHN_LORESERVE && \
-				    sym->st_name && \
+				    sym->st_name && sym->st_name < str_size && \
 				    /* Minor optimization to avoid strcmp. */ \
 				    symname[0] == '_' && symname[1] == '_') { \
 					/* Blacklist internal C library symbols. */ \