Le 20/06/2018 à 22:36, Kees Cook a écrit :
On Wed, Jun 20, 2018 at 12:30 PM, Christophe Leroy
<christophe.leroy@xxxxxx> wrote:
On 06/20/2018 07:03 PM, Kees Cook wrote:
In the quest to remove all stack VLA usage from the kernel[1], this
removes the VLAs in SHASH_DESC_ON_STACK (via crypto_shash_descsize())
by using the maximum allowable size (which is now more clearly captured
in a macro). Similar limits are turned into macros as well.
[1]
https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Got the following warnings:
crypto/testmgr.c: In function ‘alg_test_crc32c.part.4’:
crypto/testmgr.c:1896:1: warning: the frame size of 2088 bytes is larger
than 1024 bytes [-Wframe-larger-than=]
crypto/hmac.c: In function ‘hmac_setkey’:
crypto/hmac.c:88:1: warning: the frame size of 2088 bytes is larger than
1024 bytes [-Wframe-larger-than=]
Ah yes. I didn't do 32-bit builds. So, here's the issue: this uncovers
the frame size problems that were hidden by in being a VLA before. It
was always possible for the frame to get this big, it's just that the
compiler couldn't see it.
For qat, I raised the -Wframe-larger-than flag. It seems we'll need to
do this in some other places too.
Maybe the issue is because I have selected 16k pages ?
Christophe
-Kees
