search for: memzero_explicit

On Mon, 2020-04-13 at 17:15 -0400, Waiman Long wrote: > Since kfree_sensitive() will do an implicit memzero_explicit(), there > is no need to call memzero_explicit() before it. Eliminate those > memzero_explicit() and simplify the call sites. 2 bits of trivia: > diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c [] > @@ -391,10 +388...

On Mon, 2020-04-13 at 17:15 -0400, Waiman Long wrote: > Since kfree_sensitive() will do an implicit memzero_explicit(), there > is no need to call memzero_explicit() before it. Eliminate those > memzero_explicit() and simplify the call sites. 2 bits of trivia: > diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c [] > @@ -391,10 +388...

Since kfree_sensitive() will do an implicit memzero_explicit(), there is no need to call memzero_explicit() before it. Eliminate those memzero_explicit() and simplify the call sites. Signed-off-by: Waiman Long <longman at redhat.com> --- .../crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c | 15 +++------------ .../crypto/allwinner/sun8i-ss/sun8i-ss-ciph...

Le 14/04/2020 ? 00:28, Waiman Long a ?crit?: > Since kfree_sensitive() will do an implicit memzero_explicit(), there > is no need to call memzero_explicit() before it. Eliminate those > memzero_explicit() and simplify the call sites. For better correctness, > the setting of keylen is also moved down after the key pointer check. > > Signed-off-by: Waiman Long <longman at redhat.com>...

Le 14/04/2020 ? 00:28, Waiman Long a ?crit?: > Since kfree_sensitive() will do an implicit memzero_explicit(), there > is no need to call memzero_explicit() before it. Eliminate those > memzero_explicit() and simplify the call sites. For better correctness, > the setting of keylen is also moved down after the key pointer check. > > Signed-off-by: Waiman Long <longman at redhat.com>...

Since kfree_sensitive() will do an implicit memzero_explicit(), there is no need to call memzero_explicit() before it. Eliminate those memzero_explicit() and simplify the call sites. For better correctness, the setting of keylen is also moved down after the key pointer check. Signed-off-by: Waiman Long <longman at redhat.com> --- .../allwinner/sun8i-...

On 4/13/20 5:31 PM, Joe Perches wrote: > On Mon, 2020-04-13 at 17:15 -0400, Waiman Long wrote: >> Since kfree_sensitive() will do an implicit memzero_explicit(), there >> is no need to call memzero_explicit() before it. Eliminate those >> memzero_explicit() and simplify the call sites. > 2 bits of trivia: > >> diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c &gt...

On 4/14/20 3:16 PM, Michal Such?nek wrote: > On Tue, Apr 14, 2020 at 12:24:36PM -0400, Waiman Long wrote: >> On 4/14/20 2:08 AM, Christophe Leroy wrote: >>> >>> Le 14/04/2020 ? 00:28, Waiman Long a ?crit?: >>>> Since kfree_sensitive() will do an implicit memzero_explicit(), there >>>> is no need to call memzero_explicit() before it. Eliminate those >>>> memzero_explicit() and simplify the call sites. For better correctness, >>>> the setting of keylen is also moved down after the key pointer check. >>>> >>>&gt...

...buffer before freeing it back > to the pool. Memset() is currently used for the buffer clearing. However, > it is entirely possible that the compiler may choose to optimize away the > memory clearing especially if LTO is being used. To make sure that this > optimization will not happen, memzero_explicit(), which is introduced > in v3.18, is now used in kzfree() to do the clearing. > > Fixes: 3ef0e5ba4673 ("slab: introduce kzfree()") > Cc: stable at vger.kernel.org > Signed-off-by: Waiman Long <longman at redhat.com> Acked-by: Michal Hocko <mhocko at suse.com>...

...eeing it back >> to the pool. Memset() is currently used for the buffer clearing. However, >> it is entirely possible that the compiler may choose to optimize away the >> memory clearing especially if LTO is being used. To make sure that this >> optimization will not happen, memzero_explicit(), which is introduced >> in v3.18, is now used in kzfree() to do the clearing. >> >> Fixes: 3ef0e5ba4673 ("slab: introduce kzfree()") >> Cc: stable at vger.kernel.org >> Signed-off-by: Waiman Long <longman at redhat.com> >> --- >> mm/slab...

...yption keys, in the buffer before freeing it back to the pool. Memset() is currently used for the buffer clearing. However, it is entirely possible that the compiler may choose to optimize away the memory clearing especially if LTO is being used. To make sure that this optimization will not happen, memzero_explicit(), which is introduced in v3.18, is now used in kzfree() to do the clearing. Fixes: 3ef0e5ba4673 ("slab: introduce kzfree()") Cc: stable at vger.kernel.org Signed-off-by: Waiman Long <longman at redhat.com> --- mm/slab_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)...

...t;a possibility". > that and I'd move "in [the] future" here. > the compiler may choose to optimize away the > memory clearing especially if LTO is being used in the future. To make sure > that this optimization will never happen "in these cases" > , memzero_explicit(), which is introduced in v3.18, is now used in "instead of"? > kzfree() to future-proof it. Davod

On Tue, Jun 16, 2020 at 11:53:50AM -0700, Joe Perches wrote: > On Mon, 2020-06-15 at 21:57 -0400, Waiman Long wrote: > > v4: > > - Break out the memzero_explicit() change as suggested by Dan Carpenter > > so that it can be backported to stable. > > - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for > > now as there can be a bit more discussion on what is best. It will be > > introduced as a s...

On Tue, Jun 16, 2020 at 11:53:50AM -0700, Joe Perches wrote: > On Mon, 2020-06-15 at 21:57 -0400, Waiman Long wrote: > > v4: > > - Break out the memzero_explicit() change as suggested by Dan Carpenter > > so that it can be backported to stable. > > - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for > > now as there can be a bit more discussion on what is best. It will be > > introduced as a s...

...t the fact buffer clearing is only needed if the data objects contain sensitive information like encrpytion key. The fact that kzfree() uses memset() to do the clearing isn't totally safe either as compiler may compile out the clearing in their optimizer. Instead, the new kfree_sensitive() uses memzero_explicit() which won't get compiled out. Waiman Long (2): mm, treewide: Rename kzfree() to kfree_sensitive() crypto: Remove unnecessary memzero_explicit() arch/s390/crypto/prng.c | 4 +-- arch/x86/power/hibernate.c | 2 +- crypto/adiantum.c...

v4: - Break out the memzero_explicit() change as suggested by Dan Carpenter so that it can be backported to stable. - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for now as there can be a bit more discussion on what is best. It will be introduced as a separate patch later on after this one is...

v4: - Break out the memzero_explicit() change as suggested by Dan Carpenter so that it can be backported to stable. - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for now as there can be a bit more discussion on what is best. It will be introduced as a separate patch later on after this one is...

On Mon, 2020-06-15 at 21:57 -0400, Waiman Long wrote: > v4: > - Break out the memzero_explicit() change as suggested by Dan Carpenter > so that it can be backported to stable. > - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for > now as there can be a bit more discussion on what is best. It will be > introduced as a separate patch later...

On Wed, Jun 17, 2020 at 01:01:30AM +0200, David Sterba wrote: > On Tue, Jun 16, 2020 at 11:53:50AM -0700, Joe Perches wrote: > > On Mon, 2020-06-15 at 21:57 -0400, Waiman Long wrote: > > > v4: > > > - Break out the memzero_explicit() change as suggested by Dan Carpenter > > > so that it can be backported to stable. > > > - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for > > > now as there can be a bit more discussion on what is best. It will be > > >...

On Thu, 2020-06-18 at 00:31 +0300, Denis Efremov wrote: > > On 6/16/20 9:53 PM, Joe Perches wrote: > > On Mon, 2020-06-15 at 21:57 -0400, Waiman Long wrote: > > > v4: > > > - Break out the memzero_explicit() change as suggested by Dan Carpenter > > > so that it can be backported to stable. > > > - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for > > > now as there can be a bit more discussion on what is best. It will be > > >...