On Mon, Jun 25, 2018 at 02:59:58PM +0200, Christophe LEROY wrote: > > > Le 25/06/2018 à 14:45, Stafford Horne a écrit : > > As of GCC 9.0.0 the build is reporting warnings like: > > > > crypto/ablkcipher.c: In function ‘crypto_ablkcipher_report’: > > crypto/ablkcipher.c:374:2: warning: ‘strncpy’ specified bound 64 equals destination size [-Wstringop-truncation] > > strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>", > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > sizeof(rblkcipher.geniv)); > > ~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > This means the strnycpy might create a non null terminated string. Fix this by > > explicitly performing '\0' termination. > > > > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > Cc: Arnd Bergmann <arnd@xxxxxxxx> > > Cc: Max Filippov <jcmvbkbc@xxxxxxxxx> > > Cc: Eric Biggers <ebiggers3@xxxxxxxxx> > > Cc: Nick Desaulniers <nick.desaulniers@xxxxxxxxx> > > Signed-off-by: Stafford Horne <shorne@xxxxxxxxx> > > --- > > crypto/ablkcipher.c | 2 ++ > > crypto/blkcipher.c | 1 + > > 2 files changed, 3 insertions(+) > > > > diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c > > index d880a4897159..1edb5000d783 100644 > > --- a/crypto/ablkcipher.c > > +++ b/crypto/ablkcipher.c > > @@ -373,6 +373,7 @@ static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) > > strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type)); > > strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>", > > sizeof(rblkcipher.geniv)); > > Is it worth copying something we are going to discard at the following line > ? Shouldn't you limit the copy to sizeof(rblkcipher.geniv) - 1 ? Hi, I thought about that, I just did it like this as I thought it might be easier to read and I noticed a few other areas in the kernel that did this way. After a closer look I can see we have both patterns, perhaps we need a mcro/helper. I don't mind either way, I can fix, if the crypto maintainers want to adjust the patch that would work too. -Stafford > > + rblkcipher.geniv[sizeof(rblkcipher.geniv) - 1] = '\0'; > > rblkcipher.blocksize = alg->cra_blocksize; > > rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize; > > @@ -447,6 +448,7 @@ static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg) > > strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type)); > > strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>", > > sizeof(rblkcipher.geniv)); > > Same comment here. > > Christophe > > > + rblkcipher.geniv[sizeof(rblkcipher.geniv) - 1] = '\0'; > > rblkcipher.blocksize = alg->cra_blocksize; > > rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize; > > diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c > > index 01c0d4aa2563..dd4dcab3766a 100644 > > --- a/crypto/blkcipher.c > > +++ b/crypto/blkcipher.c > > @@ -512,6 +512,7 @@ static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) > > strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type)); > > strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>", > > sizeof(rblkcipher.geniv)); > > + rblkcipher.geniv[sizeof(rblkcipher.geniv) - 1] = '\0'; > > rblkcipher.blocksize = alg->cra_blocksize; > > rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize; > >
