On Thu, Nov 29, 2018 at 06:59:50AM +0000, David CARLIER wrote: > Meant regardless how the kernel is compiled (ie optimisation level), > the contexts are guaranteed to be wiped because of the memory fences > used. Please avoid top-posting. > On Thu, 29 Nov 2018 at 06:49, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Wed, Nov 28, 2018 at 07:36:50PM +0000, David CARLIER wrote: > > > There might be a little performance drop but to make sure it stands > > > by it comments, we really wipe the whole context after usage. > > > --- > > > crypto/chacha20poly1305.c | 3 ++- > > > crypto/md5.c | 2 +- > > > crypto/rmd128.c | 3 ++- > > > crypto/rmd160.c | 3 ++- > > > crypto/rmd256.c | 3 ++- > > > crypto/rmd320.c | 3 ++- > > > crypto/sha3_generic.c | 3 ++- > > > 7 files changed, 13 insertions(+), 7 deletions(-) > > > > > > diff --git a/crypto/chacha20poly1305.c b/crypto/chacha20poly1305.c > > > index 600afa99941f..6e93d998109e 100644 > > > --- a/crypto/chacha20poly1305.c > > > +++ b/crypto/chacha20poly1305.c > > > @@ -19,6 +19,7 @@ > > > #include <linux/init.h> > > > #include <linux/kernel.h> > > > #include <linux/module.h> > > > +#include <linux/string.h> > > > > > > #include "internal.h" > > > > > > @@ -388,7 +389,7 @@ static int poly_genkey(struct aead_request *req) > > > } > > > > > > sg_init_table(creq->src, 1); > > > - memset(rctx->key, 0, sizeof(rctx->key)); > > > + memzero_explicit(rctx->key, sizeof(rctx->key)); > > > > Please explain the purpose of this patch. As it stands this > > makes no sense. memzero_explicit is really only useful for stack memory. You need to explain why it makes sense to use it in this context. For example, by providing an example of a miscompile or how it is even possible for this to happen. Thanks, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
