[v2,05/11] malloc: malloc_elem_join_adjacent_free can return null
Checks
Commit Message
From: Sinan Kaya <okaya@kernel.org>
In malloc_heap_add_memory result of call to malloc_elem_join_adjacent_free
is dereferenced here and may be null.
Signed-off-by: Sinan Kaya <okaya@kernel.org>
---
lib/eal/common/malloc_heap.c | 2 ++
1 file changed, 2 insertions(+)
Comments
2022-11-21 17:32 (UTC-0500), okaya@kernel.org:
> From: Sinan Kaya <okaya@kernel.org>
>
> In malloc_heap_add_memory result of call to malloc_elem_join_adjacent_free
> is dereferenced here and may be null.
It may not:
"malloc_elem_join_adjacent_free()" never returns NULL by definition.
Would annotating "malloc_elem_join_adjacent_free()" result
(and maybe the argument too)
convince codeql that the check is not needed?
A comment to the series:
I'm against adding extra checks *only* to silence some tool,
not because they're overly defensive,
but because they misrepresent the code assumptions,
making the understanding harder.
Returning false if assumptions are broken is arguably no better then crashing,
because this means that either the internal state is inconsistent
or the caller has supplied invalid arguments (logical error up the stack).
@@ -97,6 +97,8 @@ malloc_heap_add_memory(struct malloc_heap *heap, struct rte_memseg_list *msl,
malloc_elem_insert(elem);
elem = malloc_elem_join_adjacent_free(elem);
+ if (elem == NULL)
+ return NULL;
malloc_elem_free_list_insert(elem);