From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Kees Cook <keescook@chromium.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
Stanimir Varbanov <stanimir.k.varbanov@gmail.com>,
Vikash Garodia <quic_vgarodia@quicinc.com>,
Bryan O'Donoghue <bryan.odonoghue@linaro.org>,
Andy Gross <agross@kernel.org>,
Bjorn Andersson <andersson@kernel.org>,
Konrad Dybcio <konrad.dybcio@linaro.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
linux-media@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH][next] media: venus: hfi_cmds: Replace one-element array with flex-array member and use __counted_by
Date: Tue, 9 Jan 2024 21:40:26 +0900 [thread overview]
Message-ID: <20240109124026.GA1012017@google.com> (raw)
In-Reply-To: <202310091252.660CFA9@keescook>
On (23/10/09 12:52), Kees Cook wrote:
> On Mon, Oct 09, 2023 at 12:42:05PM -0600, Gustavo A. R. Silva wrote:
> > Array `data` in `struct hfi_sfr` is being used as a fake flexible array
> > at run-time:
> >
> > drivers/media/platform/qcom/venus/hfi_venus.c:
> > 1033 p = memchr(sfr->data, '\0', sfr->buf_size);
> > 1034 /*
> > 1035 * SFR isn't guaranteed to be NULL terminated since SYS_ERROR indicates
> > 1036 * that Venus is in the process of crashing.
> > 1037 */
> > 1038 if (!p)
> > 1039 sfr->data[sfr->buf_size - 1] = '\0';
> > 1040
> > 1041 dev_err_ratelimited(dev, "SFR message from FW: %s\n", sfr->data);
> >
> > Fake flexible arrays are deprecated, and should be replaced by
> > flexible-array members. So, replace one-element array with a
> > flexible-array member in `struct hfi_sfr`.
> >
> > While there, also annotate array `data` with __counted_by() to prepare
> > for the coming implementation by GCC and Clang of the __counted_by
> > attribute. Flexible array members annotated with __counted_by can have
> > their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
> > array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> > functions).
> >
> > This results in no differences in binary output.
>
> Thanks for checking!
Sorry for shameless plug, a quick question: has any compiler implemented
support for counted_by() at this point?
next prev parent reply other threads:[~2024-01-09 12:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-09 18:42 [PATCH][next] media: venus: hfi_cmds: Replace one-element array with flex-array member and use __counted_by Gustavo A. R. Silva
2023-10-09 19:52 ` Kees Cook
2024-01-09 12:40 ` Sergey Senozhatsky [this message]
2024-01-09 13:17 ` Gustavo A. R. Silva
2024-01-09 13:28 ` Sergey Senozhatsky
2024-01-09 13:59 ` Gustavo A. R. Silva
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