From: Kees Cook <keescook@chromium.org>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
Peter Rosin <peda@axentia.se>, Wolfram Sang <wsa@kernel.org>,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH] i2c: mux: harden i2c_mux_alloc() against integer overflows
Date: Fri, 16 Sep 2022 01:07:25 -0700 [thread overview]
Message-ID: <202209160101.2A240E9@keescook> (raw)
In-Reply-To: <YyMyKQnWgu0SL6jj@kadam>
On Thu, Sep 15, 2022 at 05:09:45PM +0300, Dan Carpenter wrote:
> It would probaby be useful to mark passed data as explicitly unsafe for
> integer overflows. Smatch already tracks user data. And if the user
> data has been capped to an unknown value. But this would be a
> completely separate flag which says that "this value came from
> size_add/mul()".
I really want a __must_check_type(size_t) attribute or something for
functions, so we can get a subset of -Wconversion warnings, etc.
> drivers/char/tpm/eventlog/tpm2.c:57 tpm2_bios_measurements_start() warn: using integer overflow function 'size_add()' for math
> [...]
> drivers/net/ethernet/intel/ice/ice_flex_pipe.c:2070 ice_pkg_buf_reserve_section() warn: using integer overflow function 'size_mul()' for math
I see size_add() and size_mul() here. I would have expected some
size_sub() opportunities too? Did nothing pop out?
--
Kees Cook
next prev parent reply other threads:[~2022-09-16 8:07 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-15 11:30 [PATCH] i2c: mux: harden i2c_mux_alloc() against integer overflows Dan Carpenter
2022-09-15 13:36 ` Peter Rosin
2022-09-15 13:51 ` Gustavo A. R. Silva
2022-09-15 14:09 ` Dan Carpenter
2022-09-16 8:07 ` Kees Cook [this message]
2022-09-16 8:23 ` Dan Carpenter
2022-09-16 13:31 ` Kees Cook
2022-09-16 14:55 ` Dan Carpenter
2022-09-16 21:31 ` Kees Cook
2022-09-16 8:01 ` Kees Cook
2022-09-16 8:20 ` Dan Carpenter
2022-09-16 19:31 ` Wolfram Sang
2022-09-19 6:35 ` Dan Carpenter
2022-09-21 20:13 ` Wolfram Sang
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