Re: [PATCH] crypto: lrw - fix rebase error after out of bounds fix

[Herbert Xu]

On Sun, Sep 30, 2018 at 09:51:16PM +0200, Ard Biesheuvel wrote:
> Due to an unfortunate interaction between commit fbe1a850b3b1
> ("crypto: lrw - Fix out-of bounds access on counter overflow") and
> commit c778f96bf347 ("crypto: lrw - Optimize tweak computation"),
> we ended up with a version of next_index() that always returns 127.
> 
> Fixes: c778f96bf347 ("crypto: lrw - Optimize tweak computation")
> Signed-off-by: Ard Biesheuvel 

Patch applied.  Thanks.
-- 
Email: Herbert Xu 
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH] crypto: lrw - fix rebase error after out of bounds fix

[Ondrej Mosnacek]

On Sun, Sep 30, 2018 at 9:51 PM Ard Biesheuvel
 wrote:
> Due to an unfortunate interaction between commit fbe1a850b3b1
> ("crypto: lrw - Fix out-of bounds access on counter overflow") and
> commit c778f96bf347 ("crypto: lrw - Optimize tweak computation"),
> we ended up with a version of next_index() that always returns 127.

Ouch, thanks for taking your time to investigate it and fix it!  You
are spot on that it was a rebase error...  I need to get better at
*always* testing what I post :/

>
> Fixes: c778f96bf347 ("crypto: lrw - Optimize tweak computation")
> Signed-off-by: Ard Biesheuvel 

Reviewed-by: Ondrej Mosnacek 

> ---
>  crypto/lrw.c | 7 +++
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/crypto/lrw.c b/crypto/lrw.c
> index 6fcf0d431185..0430ccd08728 100644
> --- a/crypto/lrw.c
> +++ b/crypto/lrw.c
> @@ -122,10 +122,9 @@ static int next_index(u32 *counter)
> int i, res = 0;
>
> for (i = 0; i < 4; i++) {
> -   if (counter[i] + 1 != 0) {
> -   res += ffz(counter[i]++);
> -   break;
> -   }
> +   if (counter[i] + 1 != 0)
> +   return res + ffz(counter[i]++);
> +
> counter[i] = 0;
> res += 32;
> }
> --
> 2.17.1
>

--
Ondrej Mosnacek 
Associate Software Engineer, Security Technologies
Red Hat, Inc.

[PATCH] crypto: lrw - fix rebase error after out of bounds fix

[Ard Biesheuvel]

Due to an unfortunate interaction between commit fbe1a850b3b1
("crypto: lrw - Fix out-of bounds access on counter overflow") and
commit c778f96bf347 ("crypto: lrw - Optimize tweak computation"),
we ended up with a version of next_index() that always returns 127.

Fixes: c778f96bf347 ("crypto: lrw - Optimize tweak computation")
Signed-off-by: Ard Biesheuvel 
---
 crypto/lrw.c | 7 +++
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/crypto/lrw.c b/crypto/lrw.c
index 6fcf0d431185..0430ccd08728 100644
--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -122,10 +122,9 @@ static int next_index(u32 *counter)
int i, res = 0;
 
for (i = 0; i < 4; i++) {
-   if (counter[i] + 1 != 0) {
-   res += ffz(counter[i]++);
-   break;
-   }
+   if (counter[i] + 1 != 0)
+   return res + ffz(counter[i]++);
+
counter[i] = 0;
res += 32;
}
-- 
2.17.1