[uclibc-ng-devel] [PATCH] dl-elf.c: Add null-pointer check

Hi, static analysis tools complain that the following code lacks a null-pointer check: ldso/ldso/dl-elf.c: /* * Add this object into the symbol chain */ if (*rpnt #ifdef __LDSO_STANDALONE_SUPPORT__ /* Do not create a new chain entry for the main executable */ && (*rpnt)->dyn #endif ) { (*rpnt)->next = _dl_malloc(sizeof(struct dyn_elf)); _dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf)); (*rpnt)->next->prev = (*rpnt); *rpnt = (*rpnt)->next; } #ifndef SHARED /* When statically linked, the first time we dlopen a DSO * the *rpnt is NULL, so we need to allocate memory for it, * and initialize the _dl_symbol_table. */ else { *rpnt = _dl_symbol_tables = _dl_malloc(sizeof(struct dyn_elf)); _dl_memset(*rpnt, 0, sizeof(struct dyn_elf)); } #endif (*rpnt)->dyn = tpnt; ^^^^^^^^^^^^^^^^^^^^ There is a check for (*rpnt == NULL) right after the first comment but the "else" case which performs an allocation does only exist if SHARED is not defined. Otherwise it may happen (at least in theory) that *rpnt=NULL when executing (*rpnt)->dyn = tpnt; Proposed fix: diff --git a/ldso/ldso/dl-elf.c b/ldso/ldso/dl-elf.c index 8210a012e..3ba3144e2 100644 --- a/ldso/ldso/dl-elf.c +++ b/ldso/ldso/dl-elf.c @@ -900,7 +900,8 @@ struct elf_resolve *_dl_load_elf_shared_library(unsigned int rflags, _dl_memset(*rpnt, 0, sizeof(struct dyn_elf)); } #endif - (*rpnt)->dyn = tpnt; + if (*rpnt) + (*rpnt)->dyn = tpnt; tpnt->usage_count++; if (tpnt->rtld_flags & RTLD_NODELETE) tpnt->usage_count++; Kind regards Frank