On Tue, Nov 16, 2021 at 12:50:58PM +0100, Greg Kroah-Hartman wrote: > On Tue, Nov 16, 2021 at 07:25:22PM +0800, Sandy Harris wrote: > > Replace memset(address,0,bytes) which may be optimised away > > with memzero_explicit(address,bytes) which resists > > such optimisation > > > > --- > > crypto/des_generic.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/crypto/des_generic.c b/crypto/des_generic.c > > index c85354a5e94c..105a32e7afea 100644 > > --- a/crypto/des_generic.c > > +++ b/crypto/des_generic.c > > @@ -30,7 +30,7 @@ static int des_setkey(struct crypto_tfm *tfm, const u8 *key, > > err = 0; > > } > > if (err) > > - memset(dctx, 0, sizeof(*dctx)); > > + memzero_explicit(dctx, sizeof(*dctx)); > > return err; > > } > > > > @@ -62,7 +62,7 @@ static int des3_ede_setkey(struct crypto_tfm *tfm, > > const u8 *key, > > err = 0; > > } > > if (err) > > - memset(dctx, 0, sizeof(*dctx)); > > + memzero_explicit(dctx, sizeof(*dctx)); > > return err; > > } > > > > Have you looked at the output of the compiler to see if this really is > needed or not? Oh wait, that's not a stack variable, how would this be optimized away at all? If it is, that's a HUGE compiler bug. Is that really happening here? thanks, greg k-h
