From: Stephan Mueller <smueller@chronox.de>
To: Edward Adam Davis <eadavis@qq.com>
Cc: herbert@gondor.apana.org.au, davem@davemloft.net, eadavis@qq.com,
linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
syzbot+e8bcd7ee3db6cb5cb875@syzkaller.appspotmail.com,
syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH V2] crypto: Mark intermediary memory as clean
Date: Mon, 18 Aug 2025 15:13:47 +0200 [thread overview]
Message-ID: <7740195.jRhZ6ZUK3Y@tauon> (raw)
In-Reply-To: <tencent_F8BAB8BB23338A9E2C1B4F4BD11BD9252E08@qq.com>
Am Montag, 18. August 2025, 14:43:36 Mitteleuropäische Sommerzeit schrieb
Edward Adam Davis:
Hi Edward,
> On Mon, 18 Aug 2025 20:30:29 +0800, Herbert Xu wrote:
> > Their values are equal, so why use sizeof to calculate?
> > Similarly, "if (sizeof(intermediary) !=
> > crypto_shash_digestsize(desc->tfm)) {", why not just use
> > SHA3_256_DIGEST_SIZE?
>
> Hi Stephan Mueller, can you explain it?
If the question is why using sizeof(intermediary) instead of
SHA3_256_DIGEST_SIZE, then it is very trivial: I always want to avoid any kind
of double work. If for any reason the buffer size of intermediary changes, the
current code only requires *one* location to fix it.
When changing the branching condition to use SHA3_256_DIGEST_SIZE, we would
have to change *two* locations which is more error-prone than to change one.
This approach is my common coding style to try to minimize the possibilities
where inconsistencies can occur.
Ciao
Stephan
next prev parent reply other threads:[~2025-08-18 13:19 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-08 8:07 [syzbot] [crypto?] KMSAN: kernel-infoleak in rng_recvmsg syzbot
2025-08-09 9:59 ` [PATCH] crypto: Prevent " Edward Adam Davis
2025-08-16 9:17 ` Herbert Xu
2025-08-17 8:51 ` Herbert Xu
2025-08-17 10:59 ` [PATCH V2] crypto: Mark intermediary memory as clean Edward Adam Davis
2025-08-17 11:40 ` Herbert Xu
2025-08-18 12:17 ` Edward Adam Davis
2025-08-18 12:30 ` Herbert Xu
2025-08-18 12:43 ` Edward Adam Davis
2025-08-18 13:13 ` Stephan Mueller [this message]
2025-08-18 13:24 ` [PATCH V3] " Edward Adam Davis
2025-08-18 13:32 ` Stephan Mueller
2025-08-30 8:45 ` Herbert Xu
2025-08-26 13:51 ` [PATCH] crypto: Prevent kernel-infoleak in rng_recvmsg Ard Biesheuvel
2025-08-26 16:58 ` Kees Cook
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