Waiman Long e27d0385df mm: add kvfree_sensitive() for freeing sensitive data objects ... [ Upstream commit d4eaa28378 ] For kvmalloc'ed data object that contains sensitive information like cryptographic keys, we need to make sure that the buffer is always cleared before freeing it. Using memset() alone for buffer clearing may not provide certainty as the compiler may compile it away. To be sure, the special memzero_explicit() has to be used. This patch introduces a new kvfree_sensitive() for freeing those sensitive data objects allocated by kvmalloc(). The relevant places where kvfree_sensitive() can be used are modified to use it. Fixes: 4f0882491a ("KEYS: Avoid false positive ENOMEM error on key read") Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Joe Perches <joe@perches.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Uladzislau Rezki <urezki@gmail.com> Link: http://lkml.kernel.org/r/20200407200318.11711-1-longman@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2020-06-20 10:24:59 +02:00
..
encrypted-keys	KEYS: Don't write out to userspace while holding key semaphore	2020-04-24 08:01:25 +02:00
big_key.c	KEYS: Don't write out to userspace while holding key semaphore	2020-04-24 08:01:25 +02:00
compat.c
compat_dh.c
dh.c
gc.c
internal.h	mm: add kvfree_sensitive() for freeing sensitive data objects	2020-06-20 10:24:59 +02:00
Kconfig
key.c	KEYS: reaching the keys quotas correctly	2020-04-24 08:00:37 +02:00
keyctl.c	mm: add kvfree_sensitive() for freeing sensitive data objects	2020-06-20 10:24:59 +02:00
keyring.c	KEYS: Don't write out to userspace while holding key semaphore	2020-04-24 08:01:25 +02:00
Makefile
permission.c
persistent.c
proc.c
process_keys.c
request_key.c
request_key_auth.c	KEYS: Don't write out to userspace while holding key semaphore	2020-04-24 08:01:25 +02:00
sysctl.c
trusted.c	KEYS: Don't write out to userspace while holding key semaphore	2020-04-24 08:01:25 +02:00
trusted.h
user_defined.c	KEYS: Don't write out to userspace while holding key semaphore	2020-04-24 08:01:25 +02:00