From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
linux-nfs@vger.kernel.org,
Trond Myklebust <trond.myklebust@hammerspace.com>,
linux-hwmon@vger.kernel.org,
Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
"Steven Rostedt (VMware)" <rostedt@goodmis.org>,
Jean Delvare <jdelvare@suse.com>,
Guenter Roeck <linux@roeck-us.net>
Subject: [RFC PATCH 0/7] runtime format string checking
Date: Sat, 27 Oct 2018 01:24:02 +0200 [thread overview]
Message-ID: <20181026232409.16100-1-linux@rasmusvillemoes.dk> (raw)
In-Reply-To: <20171108223020.24487-1-linux@rasmusvillemoes.dk>
This is a resurrection of something I sent out about a year ago. In
the relatively few places where we use a non-literal as format string,
we can annotate the source with a fmtcheck() call that will (a) at
build time, allow the compiler to check the variadic arguments against
the template, and (b) at runtime, check that the format specifiers
present in the actual format string match those in the template (and
if not, WARN and use the template to ensure runtime type safety).
Finding places to annotate is just
make -j8 KCFLAGS='-Wformat-nonliteral'
So far, in about half the places I looked, one might as well get
completely rid of the non-literal format string. Patches 5,6,7 are
some examples of where one might add fmtcheck() calls. I don't think
we can get to a state where we can unconditionally add
-Wformat-nonliteral to the build, but I think there's a lot of
low-hanging fruit.
This is on top of Miguel's compiler attributes series [1], which I
hope will land in mainline soon.
[1] https://github.com/ojeda/linux.git tags/compiler-attributes-for-linus-4.20-rc1
Rasmus Villemoes (7):
compiler_attributes.h: add __attribute__((format_arg)) shorthand
lib/vsprintf.c: add fmtcheck utility
kernel.h: implement fmtmatch() wrapper around fmtcheck()
lib/test_printf.c: add a few fmtcheck() test cases
kernel/kthread.c: do runtime check of format string in
kthread_create_on_cpu()
nfs: use fmtcheck() in root_nfs_data
drivers: hwmon: add runtime format string checking
drivers/hwmon/hwmon.c | 3 +-
fs/nfs/nfsroot.c | 2 +-
include/linux/compiler_attributes.h | 13 ++++++
include/linux/kernel.h | 25 +++++++++++
kernel/kthread.c | 4 +-
lib/Kconfig.debug | 9 ++++
lib/test_printf.c | 43 +++++++++++++++++++
lib/vsprintf.c | 65 +++++++++++++++++++++++++++++
8 files changed, 160 insertions(+), 4 deletions(-)
--
2.19.1.6.gbde171bbf5
next prev parent reply other threads:[~2018-10-26 23:24 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-08 22:30 [RFC 0/6] some compile- and run-time format checking Rasmus Villemoes
2017-11-08 22:30 ` [kernel-hardening] " Rasmus Villemoes
2017-11-08 22:30 ` [RFC 1/6] plugins: implement format_template attribute Rasmus Villemoes
2017-11-08 22:30 ` [kernel-hardening] " Rasmus Villemoes
2017-11-08 22:30 ` [RFC 2/6] compiler.h: add __format_template Rasmus Villemoes
2017-11-08 22:30 ` [kernel-hardening] " Rasmus Villemoes
2017-11-08 22:30 ` [RFC 3/6] compiler.h: add __attribute__((format_arg)) shorthand Rasmus Villemoes
2017-11-08 22:30 ` [kernel-hardening] " Rasmus Villemoes
2017-11-08 22:30 ` [RFC 4/6] lib/vsprintf.c: add fmtcheck utility Rasmus Villemoes
2017-11-08 22:30 ` [kernel-hardening] " Rasmus Villemoes
2017-11-09 1:08 ` Kees Cook
2017-11-09 1:08 ` [kernel-hardening] " Kees Cook
2017-11-08 22:30 ` [RFC 5/6] kernel.h: implement fmtmatch() wrapper around fmtcheck() Rasmus Villemoes
2017-11-08 22:30 ` [kernel-hardening] " Rasmus Villemoes
2017-11-08 22:30 ` [RFC 6/6] lib/test_printf.c: add a few fmtcheck() test cases Rasmus Villemoes
2017-11-08 22:30 ` [kernel-hardening] " Rasmus Villemoes
2017-11-09 1:11 ` [RFC 0/6] some compile- and run-time format checking Kees Cook
2017-11-09 1:11 ` [kernel-hardening] " Kees Cook
2017-11-09 14:08 ` Rasmus Villemoes
2017-11-09 14:08 ` [kernel-hardening] " Rasmus Villemoes
2018-10-26 23:24 ` Rasmus Villemoes [this message]
2018-10-26 23:24 ` [RFC PATCH 1/7] compiler_attributes.h: add __attribute__((format_arg)) shorthand Rasmus Villemoes
2018-10-27 12:06 ` Miguel Ojeda
2018-10-29 10:20 ` Rasmus Villemoes
2018-10-29 19:17 ` Miguel Ojeda
2018-11-02 10:36 ` Miguel Ojeda
2018-11-02 10:43 ` Rasmus Villemoes
2019-01-09 10:57 ` Miguel Ojeda
2018-10-26 23:24 ` [RFC PATCH 2/7] lib/vsprintf.c: add fmtcheck utility Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 3/7] kernel.h: implement fmtmatch() wrapper around fmtcheck() Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 4/7] lib/test_printf.c: add a few fmtcheck() test cases Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 5/7] kernel/kthread.c: do runtime check of format string in kthread_create_on_cpu() Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 6/7] nfs: use fmtcheck() in root_nfs_data Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 7/7] drivers: hwmon: add runtime format string checking Rasmus Villemoes
2018-10-27 17:44 ` Guenter Roeck
2018-10-30 20:58 ` [RFC PATCH 0/7] " Kees Cook
2018-11-01 22:06 ` Rasmus Villemoes
2018-11-01 22:57 ` Kees Cook
2018-11-02 20:09 ` Rasmus Villemoes
2018-11-02 20:46 ` Kees Cook
2018-11-05 9:33 ` Rasmus Villemoes
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