From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Richard Weinberger <richard@nod.at>
Cc: linux-hardening@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, keescook@chromium.org,
"Petr Mladek" <pmladek@suse.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Sergey Senozhatsky" <senozhatsky@chromium.org>,
"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
"David S. Miller" <davem@davemloft.net>,
"Eric Dumazet" <edumazet@google.com>,
"Jakub Kicinski" <kuba@kernel.org>,
"Paolo Abeni" <pabeni@redhat.com>,
"Miguel Ojeda" <ojeda@kernel.org>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Wedson Almeida Filho" <wedsonaf@gmail.com>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <benno.lossin@proton.me>,
"Alexei Starovoitov" <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Jesper Dangaard Brouer" <hawk@kernel.org>,
"John Fastabend" <john.fastabend@gmail.com>
Subject: Re: [RFC PATCH 1/1] vsprintf: Warn on integer scanning overflows
Date: Thu, 8 Jun 2023 17:27:50 +0300 [thread overview]
Message-ID: <ZIHlZsPMZ2dI5/yG@smile.fi.intel.com> (raw)
In-Reply-To: <20230607223755.1610-2-richard@nod.at>
On Thu, Jun 08, 2023 at 12:37:55AM +0200, Richard Weinberger wrote:
> The scanf function family has no way to indicate overflows
> while scanning. As consequence users of these function have to make
> sure their input cannot cause an overflow.
> Since this is not always the case add WARN_ON_ONCE() guards to
> trigger a warning upon an overflow.
...
> if (prefix_chars < max_chars) {
> rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
> + WARN_ON_ONCE(rv & KSTRTOX_OVERFLOW);
This seems incorrect. simple_strto*() are okay to overflow. It's by design.
> /* FIXME */
...and that's why this one is here.
> cp += (rv & ~KSTRTOX_OVERFLOW);
> } else {
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2023-06-08 14:34 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-07 22:37 [RFC PATCH 0/1] Integer overflows while scanning for integers Richard Weinberger
2023-06-07 22:37 ` [RFC PATCH 1/1] vsprintf: Warn on integer scanning overflows Richard Weinberger
2023-06-08 14:27 ` Andy Shevchenko [this message]
2023-06-08 16:14 ` Richard Weinberger
2023-06-08 16:23 ` Andy Shevchenko
2023-06-12 6:16 ` kernel test robot
2023-06-07 23:36 ` [RFC PATCH 0/1] Integer overflows while scanning for integers Kees Cook
2023-06-08 15:27 ` Petr Mladek
2023-06-08 16:12 ` Richard Weinberger
2023-06-08 16:19 ` Greg KH
2023-06-08 16:23 ` Richard Weinberger
2023-06-09 10:10 ` Rasmus Villemoes
2023-06-09 17:02 ` Petr Mladek
2023-06-09 17:46 ` Linus Torvalds
2023-06-10 19:31 ` David Laight
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