Messages in this thread | | | From | Kees Cook <> | Date | Wed, 18 Jul 2018 21:29:38 -0700 | Subject | Re: [PATCH] rxrpc: Reuse SKCIPHER_REQUEST_ON_STACK buffer |
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On Mon, Jul 16, 2018 at 3:17 AM, Arnd Bergmann <arnd@arndb.de> wrote: > On Mon, Jul 16, 2018 at 5:49 AM, Kees Cook <keescook@chromium.org> wrote: >> The use of SKCIPHER_REQUEST_ON_STACK() will trigger FRAME_WARN warnings >> (when less than 2048) once the VLA is no longer hidden from the check: >> >> net/rxrpc/rxkad.c:398:1: warning: the frame size of 1152 bytes is larger than 1024 bytes [-Wframe-larger-than=] >> net/rxrpc/rxkad.c:242:1: warning: the frame size of 1152 bytes is larger than 1024 bytes [-Wframe-larger-than=] >> >> This passes the initial SKCIPHER_REQUEST_ON_STACK allocation to the leaf >> functions for reuse. Two requests allocated on the stack are not needed >> when only one is used at a time. >> >> Signed-off-by: Kees Cook <keescook@chromium.org> > > This looks like a very nice solution to the problem. > > Acked-by: Arnd Bergmann <arnd@arndb.de> > > Since the large stack usage could already cause problems in older kernels, > should this be backported to stable kernels as well?
I don't think this hits the bar for doing a -stable patch, but if you think I should, I can do it.
-Kees
-- Kees Cook Pixel Security
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