From: Josh Law <objecting@objecting.org>
To: Petr Mladek <pmladek@suse.com>, Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Josh Law <objecting@objecting.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH 0/4] lib/vsprintf: assorted bug fixes
Date: Tue, 24 Mar 2026 22:49:36 +0000 [thread overview]
Message-ID: <20260324224940.50508-1-objecting@objecting.org> (raw)
Four small fixes found during an audit of lib/vsprintf.c:
1. bstr_printf() fails to advance the args pointer past a
pre-rendered pointer string when the output buffer is full,
corrupting all subsequent output.
2. vbin_printf() writes end[-1] unconditionally when NUL-terminating
a pointer string, which is an OOB write when size is zero.
3. vsscanf() uses s16 for field_width but assigns from skip_atoi()
which returns int, silently truncating large widths to negative
and aborting parsing.
4. format_decode() is missing a (u8) cast on the second lookup into
the format_state table, allowing a negative array index on
signed-char platforms.
Josh Law (4):
lib/vsprintf: always advance args in bstr_printf() pointer path
lib/vsprintf: fix OOB write in vbin_printf() when size is zero
lib/vsprintf: use int for field_width in vsscanf()
lib/vsprintf: add missing (u8) cast in format_decode() lookup
lib/vsprintf.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
--
2.34.1
next reply other threads:[~2026-03-24 22:50 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-24 22:49 Josh Law [this message]
2026-03-24 22:49 ` [PATCH 1/4] lib/vsprintf: always advance args in bstr_printf() pointer path Josh Law
2026-03-30 16:06 ` Petr Mladek
2026-03-24 22:49 ` [PATCH 2/4] lib/vsprintf: fix OOB write in vbin_printf() when size is zero Josh Law
2026-03-30 16:17 ` Petr Mladek
2026-03-30 16:31 ` Steven Rostedt
2026-03-30 16:32 ` Josh Law
2026-03-30 16:32 ` Josh Law
2026-03-30 16:32 ` Josh Law
2026-03-30 16:34 ` Josh Law
2026-03-24 22:49 ` [PATCH 3/4] lib/vsprintf: use int for field_width in vsscanf() Josh Law
2026-03-25 12:00 ` Andy Shevchenko
2026-03-31 14:31 ` Petr Mladek
2026-03-31 15:35 ` David Laight
2026-03-31 16:12 ` Petr Mladek
2026-03-31 16:13 ` Josh Law
2026-03-31 16:13 ` Josh Law
2026-03-31 16:13 ` Josh Law
2026-04-01 14:22 ` David Laight
2026-04-01 18:29 ` David Laight
2026-03-24 22:49 ` [PATCH 4/4] lib/vsprintf: add missing (u8) cast in format_decode() lookup Josh Law
2026-03-25 12:02 ` Andy Shevchenko
2026-03-31 14:33 ` Petr Mladek
2026-03-31 14:44 ` Josh Law
2026-03-31 14:44 ` Josh Law
2026-03-25 12:05 ` [PATCH 0/4] lib/vsprintf: assorted bug fixes Andy Shevchenko
2026-03-25 17:20 ` Josh Law
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