From: Eric Biggers <ebiggers@kernel.org>
To: Jarkko Sakkinen <jarkko@kernel.org>
Cc: keyrings@vger.kernel.org, David Howells <dhowells@redhat.com>,
Denis Kenzior <denkenz@gmail.com>,
Marcel Holtmann <marcel@holtmann.org>,
James Morris <james.morris@microsoft.com>,
linux-crypto@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 1/3] KEYS: asym_tpm: fix buffer overreads in extract_key_parameters()
Date: Tue, 18 Jan 2022 16:59:47 -0800 [thread overview]
Message-ID: <Yedigyl+WNhB58MO@sol.localdomain> (raw)
In-Reply-To: <YeM/YIUTEwL4jNf3@iki.fi>
On Sat, Jan 15, 2022 at 11:40:48PM +0200, Jarkko Sakkinen wrote:
> >
> > - Avoid integer overflows when validating size fields; 'sz + 12' and
> > '4 + sz' overflowed if 'sz' is near U32_MAX.
>
> So we have a struct tpm_header in include/linux/tpm.h. It would be way
> more informative to use sizeof(struct tpm_header) than number 12, even
> if the patch does not otherwise use the struct. It tells what it is, 12
> does not.
I don't think that would be an improvement, given that the code is using
hard-coded offsets. If it's reading 4 bytes from cur + 8, it's much easier to
understand that it needs 12 bytes than 'sizeof(struct tpm_header)' bytes.
I'd certainly encourage whoever is maintaining this code to change it to use
structs instead, but that's not what this patch is meant to do.
- Eric
next prev parent reply other threads:[~2022-01-19 0:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-13 23:54 [PATCH 0/3] KEYS: fixes for asym_tpm keys Eric Biggers
2022-01-13 23:54 ` [PATCH 1/3] KEYS: asym_tpm: fix buffer overreads in extract_key_parameters() Eric Biggers
2022-01-15 21:40 ` Jarkko Sakkinen
2022-01-19 0:59 ` Eric Biggers [this message]
2022-01-26 14:21 ` Jarkko Sakkinen
2022-01-26 14:22 ` Jarkko Sakkinen
2022-01-28 19:00 ` Eric Biggers
2022-02-08 9:30 ` Jarkko Sakkinen
2022-01-13 23:54 ` [PATCH 2/3] KEYS: asym_tpm: fix incorrect comment Eric Biggers
2022-01-15 19:12 ` Jarkko Sakkinen
2022-01-13 23:54 ` [PATCH 3/3] KEYS: asym_tpm: rename derive_pub_key() Eric Biggers
2022-01-15 19:09 ` Jarkko Sakkinen
2022-01-14 14:54 ` [PATCH 0/3] KEYS: fixes for asym_tpm keys Denis Kenzior
2022-01-15 21:42 ` Jarkko Sakkinen
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