diff options
| author | William Kucharski <william.kucharski@oracle.com> | 2020-08-06 23:18:17 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-07 11:33:22 -0700 |
| commit | fa9ba3aa89f9f1c003b5f5cde893bbbc140c7223 (patch) | |
| tree | d099883fd711d6af50a06e5a60c0656fc7bdaae9 | |
| parent | 453431a54934d917153c65211b2dabf45562ca88 (diff) | |
| download | linux-fa9ba3aa89f9f1c003b5f5cde893bbbc140c7223.tar.bz2 | |
mm: ksize() should silently accept a NULL pointer
Other mm routines such as kfree() and kzfree() silently do the right thing
if passed a NULL pointer, so ksize() should do the same.
Signed-off-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200616225409.4670-1-william.kucharski@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/slab_common.c | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index f47a097bb4b8..e493203b5002 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -1681,10 +1681,9 @@ static __always_inline void *__do_krealloc(const void *p, size_t new_size, gfp_t flags) { void *ret; - size_t ks = 0; + size_t ks; - if (p) - ks = ksize(p); + ks = ksize(p); if (ks >= new_size) { p = kasan_krealloc((void *)p, new_size, flags); @@ -1744,10 +1743,9 @@ void kfree_sensitive(const void *p) size_t ks; void *mem = (void *)p; - if (unlikely(ZERO_OR_NULL_PTR(mem))) - return; ks = ksize(mem); - memzero_explicit(mem, ks); + if (ks) + memzero_explicit(mem, ks); kfree(mem); } EXPORT_SYMBOL(kfree_sensitive); @@ -1770,8 +1768,6 @@ size_t ksize(const void *objp) { size_t size; - if (WARN_ON_ONCE(!objp)) - return 0; /* * We need to check that the pointed to object is valid, and only then * unpoison the shadow memory below. We use __kasan_check_read(), to @@ -1785,7 +1781,7 @@ size_t ksize(const void *objp) * We want to perform the check before __ksize(), to avoid potentially * crashing in __ksize() due to accessing invalid metadata. */ - if (unlikely(objp == ZERO_SIZE_PTR) || !__kasan_check_read(objp, 1)) + if (unlikely(ZERO_OR_NULL_PTR(objp)) || !__kasan_check_read(objp, 1)) return 0; size = __ksize(objp); |