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| author | Waiman Long <longman@redhat.com> | 2020-06-05 02:48:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-06-20 11:24:59 +0300 |
| commit | e27d0385dfad1182bae9b582aff9e19e5d024a26 (patch) | |
| tree | 14b6a62723c23358501109138ba146ab0ce85924 /include | |
| parent | 527e2ec8e7804e3d2ef1c6d52866efd849750faf (diff) | |
| download | linux-e27d0385dfad1182bae9b582aff9e19e5d024a26.tar.xz | |
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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mm.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 6f852d5fbada..156940758fc5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -548,6 +548,7 @@ static inline void *kvmalloc_array(size_t n, size_t size, gfp_t flags) } extern void kvfree(const void *addr); +extern void kvfree_sensitive(const void *addr, size_t len); /* * Mapcount of compound page as a whole, does not include mapped sub-pages. |