kernel-fxtec-pro1x/security/keys
Waiman Long cdfd1ec690 mm: add kvfree_sensitive() for freeing sensitive data objects
[ Upstream commit d4eaa2837851db2bfed572898bfc17f9a9f9151e ]

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: 4f0882491a14 ("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>
2020-06-22 09:05:01 +02:00
..
encrypted-keys KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:30:24 +02:00
big_key.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:30:24 +02:00
compat.c
compat_dh.c
dh.c
gc.c
internal.h mm: add kvfree_sensitive() for freeing sensitive data objects 2020-06-22 09:05:01 +02:00
Kconfig
key.c KEYS: reaching the keys quotas correctly 2020-04-17 10:48:46 +02:00
keyctl.c mm: add kvfree_sensitive() for freeing sensitive data objects 2020-06-22 09:05:01 +02:00
keyring.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:30:24 +02:00
Makefile
permission.c
persistent.c
proc.c keys: Fix proc_keys_next to increase position index 2020-04-21 09:03:08 +02:00
process_keys.c
request_key.c
request_key_auth.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:30:24 +02:00
sysctl.c
trusted.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:30:24 +02:00
trusted.h
user_defined.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:30:24 +02:00