linux/security/keys
Waiman Long 0b11ec4ae5 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>
2020-06-17 16:40:23 +02:00
..
encrypted-keys KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:36:45 +02:00
Kconfig request_key improvements 2019-07-08 19:19:37 -07:00
Makefile KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2] 2018-10-26 09:30:46 +01:00
big_key.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:36:45 +02:00
compat.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
compat_dh.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
dh.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
gc.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
internal.h mm: add kvfree_sensitive() for freeing sensitive data objects 2020-06-17 16:40:23 +02:00
key.c KEYS: reaching the keys quotas correctly 2020-04-17 10:50:11 +02:00
keyctl.c mm: add kvfree_sensitive() for freeing sensitive data objects 2020-06-17 16:40:23 +02:00
keyctl_pkey.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
keyring.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:36:45 +02:00
permission.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
persistent.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
proc.c keys: Fix proc_keys_next to increase position index 2020-04-21 09:04:58 +02:00
process_keys.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
request_key.c keys: ensure that ->match_free() is called in request_key_and_link() 2019-08-30 11:10:55 -07:00
request_key_auth.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:36:45 +02:00
sysctl.c proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
trusted.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:36:45 +02:00
user_defined.c KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:36:45 +02:00