[PATCH 0/1] Fix null-pointer dereference in nano-malloc

[Cyril Yared]

Commit 84d068971 introduced a null-pointer dereference in
nano-malloc when the following two conditions are met:

1). The free_list has no items (= NULL).
2). The call to sbrk_aligned returns -1 (failure).

On line 325 of newlib/libc/stdlib/nano-mallocr.c, there is a check:

if ((char *)p + p->size == (char *)_SBRK_R(RCALL 0))
{

If the two conditions are met, then p = free_list = NULL so p->size will be
a null-pointer dereference.

Cyril Yared (1):
  Fix a potential null-pointer dereference in nano-malloc when calling
    malloc() while the free_list is empty and the call to sbrk_aligned
    fails.

 newlib/libc/stdlib/nano-mallocr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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