linux-kernel - [PATCH v8 2/9] crypto: cbc: Remove VLA usage

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180807211843.47586-3-keescook@chromium.org>
Date:   Tue,  7 Aug 2018 14:18:36 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Herbert Xu <herbert@...dor.apana.org.au>
Cc:     Kees Cook <keescook@...omium.org>,
        Eric Biggers <ebiggers@...gle.com>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Giovanni Cabiddu <giovanni.cabiddu@...el.com>,
        Alasdair Kergon <agk@...hat.com>,
        Mike Snitzer <snitzer@...hat.com>,
        Tudor-Dan Ambarus <tudor.ambarus@...rochip.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Arnd Bergmann <arnd@...db.de>,
        Will Deacon <will.deacon@....com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        David Woodhouse <dwmw@...zon.co.uk>,
        Matthew Wilcox <willy@...radead.org>,
        "David S. Miller" <davem@...emloft.net>,
        "Gustavo A. R. Silva" <gustavo@...eddedor.com>,
        linux-crypto@...r.kernel.org, dm-devel@...hat.com,
        qat-linux@...el.com, linux-kernel@...r.kernel.org
Subject: [PATCH v8 2/9] crypto: cbc: Remove VLA usage

In the quest to remove all stack VLA usage from the kernel[1], this
uses the upper bounds on blocksize. Since this is always a cipher
blocksize, use the existing cipher max blocksize.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Signed-off-by: Kees Cook <keescook@...omium.org>
---
 include/crypto/cbc.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/crypto/cbc.h b/include/crypto/cbc.h
index f5b8bfc22e6d..3bf28beefa33 100644
--- a/include/crypto/cbc.h
+++ b/include/crypto/cbc.h
@@ -113,7 +113,7 @@ static inline int crypto_cbc_decrypt_inplace(
 	unsigned int bsize = crypto_skcipher_blocksize(tfm);
 	unsigned int nbytes = walk->nbytes;
 	u8 *src = walk->src.virt.addr;
-	u8 last_iv[bsize];
+	u8 last_iv[MAX_CIPHER_BLOCKSIZE];
 
 	/* Start of the last block. */
 	src += nbytes - (nbytes & (bsize - 1)) - bsize;
-- 
2.17.1