From 453431a54934d917153c65211b2dabf45562ca88 Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Thu, 6 Aug 2020 23:18:13 -0700 Subject: mm, treewide: rename kzfree() to kfree_sensitive() As said by Linus: A symmetric naming is only helpful if it implies symmetries in use. Otherwise it's actively misleading. In "kzalloc()", the z is meaningful and an important part of what the caller wants. In "kzfree()", the z is actively detrimental, because maybe in the future we really _might_ want to use that "memfill(0xdeadbeef)" or something. The "zero" part of the interface isn't even _relevant_. The main reason that kzfree() exists is to clear sensitive information that should not be leaked to other future users of the same memory objects. Rename kzfree() to kfree_sensitive() to follow the example of the recently added kvfree_sensitive() and make the intention of the API more explicit. In addition, memzero_explicit() is used to clear the memory to make sure that it won't get optimized away by the compiler. The renaming is done by using the command sequence: git grep -w --name-only kzfree |\ xargs sed -i 's/kzfree/kfree_sensitive/' followed by some editing of the kfree_sensitive() kerneldoc and adding a kzfree backward compatibility macro in slab.h. [akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h] [akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more] Suggested-by: Joe Perches Signed-off-by: Waiman Long Signed-off-by: Andrew Morton Acked-by: David Howells Acked-by: Michal Hocko Acked-by: Johannes Weiner Cc: Jarkko Sakkinen Cc: James Morris Cc: "Serge E. Hallyn" Cc: Joe Perches Cc: Matthew Wilcox Cc: David Rientjes Cc: Dan Carpenter Cc: "Jason A . Donenfeld" Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com Signed-off-by: Linus Torvalds --- include/crypto/aead.h | 2 +- include/crypto/akcipher.h | 2 +- include/crypto/gf128mul.h | 2 +- include/crypto/hash.h | 2 +- include/crypto/internal/acompress.h | 2 +- include/crypto/kpp.h | 2 +- include/crypto/skcipher.h | 2 +- include/linux/slab.h | 4 +++- 8 files changed, 10 insertions(+), 8 deletions(-) (limited to 'include') diff --git a/include/crypto/aead.h b/include/crypto/aead.h index 62c68550aab6..c32a6f5664e9 100644 --- a/include/crypto/aead.h +++ b/include/crypto/aead.h @@ -425,7 +425,7 @@ static inline struct aead_request *aead_request_alloc(struct crypto_aead *tfm, */ static inline void aead_request_free(struct aead_request *req) { - kzfree(req); + kfree_sensitive(req); } /** diff --git a/include/crypto/akcipher.h b/include/crypto/akcipher.h index 6924b091adec..1d3aa252caba 100644 --- a/include/crypto/akcipher.h +++ b/include/crypto/akcipher.h @@ -207,7 +207,7 @@ static inline struct akcipher_request *akcipher_request_alloc( */ static inline void akcipher_request_free(struct akcipher_request *req) { - kzfree(req); + kfree_sensitive(req); } /** diff --git a/include/crypto/gf128mul.h b/include/crypto/gf128mul.h index fa0a63d298dc..81330c6446f6 100644 --- a/include/crypto/gf128mul.h +++ b/include/crypto/gf128mul.h @@ -230,7 +230,7 @@ void gf128mul_4k_bbe(be128 *a, const struct gf128mul_4k *t); void gf128mul_x8_ble(le128 *r, const le128 *x); static inline void gf128mul_free_4k(struct gf128mul_4k *t) { - kzfree(t); + kfree_sensitive(t); } diff --git a/include/crypto/hash.h b/include/crypto/hash.h index 19ce91f2359f..0d1b403888c9 100644 --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -606,7 +606,7 @@ static inline struct ahash_request *ahash_request_alloc( */ static inline void ahash_request_free(struct ahash_request *req) { - kzfree(req); + kfree_sensitive(req); } static inline void ahash_request_zero(struct ahash_request *req) diff --git a/include/crypto/internal/acompress.h b/include/crypto/internal/acompress.h index cf478681b53e..cfc47e18820f 100644 --- a/include/crypto/internal/acompress.h +++ b/include/crypto/internal/acompress.h @@ -46,7 +46,7 @@ static inline struct acomp_req *__acomp_request_alloc(struct crypto_acomp *tfm) static inline void __acomp_request_free(struct acomp_req *req) { - kzfree(req); + kfree_sensitive(req); } /** diff --git a/include/crypto/kpp.h b/include/crypto/kpp.h index cd9a9b500624..88b591215d5c 100644 --- a/include/crypto/kpp.h +++ b/include/crypto/kpp.h @@ -187,7 +187,7 @@ static inline struct kpp_request *kpp_request_alloc(struct crypto_kpp *tfm, */ static inline void kpp_request_free(struct kpp_request *req) { - kzfree(req); + kfree_sensitive(req); } /** diff --git a/include/crypto/skcipher.h b/include/crypto/skcipher.h index 5663f71198b3..6a733b171a5d 100644 --- a/include/crypto/skcipher.h +++ b/include/crypto/skcipher.h @@ -508,7 +508,7 @@ static inline struct skcipher_request *skcipher_request_alloc( */ static inline void skcipher_request_free(struct skcipher_request *req) { - kzfree(req); + kfree_sensitive(req); } static inline void skcipher_request_zero(struct skcipher_request *req) diff --git a/include/linux/slab.h b/include/linux/slab.h index 6d454886bcaf..0884d82c55ee 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -186,10 +186,12 @@ void memcg_deactivate_kmem_caches(struct mem_cgroup *, struct mem_cgroup *); */ void * __must_check krealloc(const void *, size_t, gfp_t); void kfree(const void *); -void kzfree(const void *); +void kfree_sensitive(const void *); size_t __ksize(const void *); size_t ksize(const void *); +#define kzfree(x) kfree_sensitive(x) /* For backward compatibility */ + #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR void __check_heap_object(const void *ptr, unsigned long n, struct page *page, bool to_user); -- cgit v1.2.3