From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: Dmitry Antipov <dmantipov@yandex.ru>
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Laight <david.laight.linux@gmail.com>,
Kees Cook <kees@kernel.org>,
"Darrick J . Wong" <djwong@kernel.org>,
linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 2/5] lib: fix memparse() to handle overflow
Date: Thu, 12 Feb 2026 15:36:12 +0200 [thread overview]
Message-ID: <aY3XTDhPmUQB2V4P@smile.fi.intel.com> (raw)
In-Reply-To: <20260212125628.739276-3-dmantipov@yandex.ru>
On Thu, Feb 12, 2026 at 03:56:25PM +0300, Dmitry Antipov wrote:
> Since '_parse_integer_limit()' (and so 'simple_strtoull()') is now
> capable to handle overflow, adjust 'memparse()' to handle overflow
> (denoted by ULLONG_MAX) returned from 'simple_strtoull()'. Also
> use 'check_shl_overflow()' to catch an overflow possibly caused
> by processing size suffix and denote it with ULLONG_MAX as well.
Assuming this is a desired check and you undertake any required
action in case of user breakage, the code wise this version LGTM,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
...
> + if (shl && likely(ptr != endptr)) {
IIUC the second check is not needed, but harmless as it's basically a shortcut
for a single allowed unit letter.
> + /* Have valid suffix with preceding number. */
> + unsigned long long val;
> +
> + if (unlikely(check_shl_overflow(ret, shl, &val)))
> + ret = ULLONG_MAX;
> + else
Id est if we came here with ret == 0, shl == 0, we would get val == 0.
> + ret = val;
> + endptr++;
> + }
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2026-02-12 13:36 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-12 12:56 [PATCH v7 0/5] lib and lib/cmdline enhancements Dmitry Antipov
2026-02-12 12:56 ` [PATCH v7 1/5] lib: fix _parse_integer_limit() to handle overflow Dmitry Antipov
2026-02-12 13:41 ` Andy Shevchenko
2026-02-12 14:32 ` David Laight
2026-02-12 14:45 ` Andy Shevchenko
2026-02-12 13:51 ` David Laight
2026-02-12 12:56 ` [PATCH v7 2/5] lib: fix memparse() " Dmitry Antipov
2026-02-12 13:36 ` Andy Shevchenko [this message]
2026-02-12 12:56 ` [PATCH v7 3/5] lib: add more string to 64-bit integer conversion overflow tests Dmitry Antipov
2026-02-12 12:56 ` [PATCH v7 4/5] lib/cmdline_kunit: add test case for memparse() Dmitry Antipov
2026-02-12 12:56 ` [PATCH v7 5/5] lib/cmdline: adjust a few comments to fix kernel-doc -Wreturn warnings Dmitry Antipov
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