From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793210530; b=f0ozgHyIxyNPrgwZA61AC/lHCryF/oNNwF2qBnV8EDf9N/Imb4tRa7V6WR9l4U+G5GIj f3wupjdkS4P7lWzPMo0gJUJr4koRnvY3xXL9rF6bClabCiJPPLcGLjjftY3kMSnXE1Nc8 gM7ZMcuA46JOdrn+yLymC0G/5FmQl1hWRyfXzGH9OCSTUcBL6vAyJji0WF3X3QzLZ4DQ+ 9JFjvcEWdpZSFA8itDTj60yDt8DPCrGe2ehCxr6HckA2/16E6hD6sGM77/1CloKQIOCsn zDjRlG33o6WpIkR738YuQ5VUNoFsPtPqnIIRQbnmHmeIEt64Hvd+JuERz7hDtm2fLTw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210530; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=UEloBFv9bEU0IdiAZtLylJogjS/CVQgMA8n+HvcnaOI=; b=ivJ2LJ7L2zeU2Ur4+unTQuj+dThTCbw1BS4Bl7O/H6/tn1rZcEdQoGzcfo4gc4H9uhkd eCVr+kDgjX1/DUAcZiYlhuWIqf5fRk5bQyX+AD2gtUdfth2+FRY5aXR/xK2wGxITMI8dL 9TPC8rA0q2oQLUTWwd/bSt0ayfeL/D6/KcF7g32jOGu/PdRrQ8jSZnlPQZmka8H0YTzGt Zrh6VW5/vxtfR1w6VTU6UowQ7QuCnjjI5Y8lwu0yg/yJlABhTvKZ8LE2axUHurAT0ZTVj oE4q035XjQVaRFFiEyHuA02zU+lZsOkDz2u91RnQRufYrkUIKtm52AA7ies8t+s6plA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=X4aIbe70; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AFEAA606A31C; Wed, 28 Oct 2026 18:02:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=X4aIbe70 Received: by smtp.kernel.org (Postfix) with ESMTPSA id BEBD51F01825; Wed, 28 Oct 2026 18:02:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210529; bh=UEloBFv9bEU0IdiAZtLylJogjS/CVQgMA8n+HvcnaOI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=X4aIbe705p7rEODUSPaIc0G9KkTWYN7GoQEXFVDucadXJswr/soRRg2slzW9tVPpm AqPd5ug6QebbDaYsEPQDjyJx9zLjVox5amHv4+oI7Z5UF0KxhesGuJ48rik8chFECk tl/3h4K2nE059ax10wuvoeO4a0MHLPXu9ZwUJScM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Luis Chamberlain , Kees Cook , Andy Shevchenko , Sasha Levin Subject: [PATCH 5.15 058/571] params: Do not go over the limit when getting the string length Date: Wed, 28 Oct 2026 17:53:25 +0100 Message-ID: <20261028170009.404003085@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Shevchenko [ Upstream commit fd0cd057a1b7351604daa6ffc91dfe28adf7225d ] We can use strnlen() even on early stages and it prevents from going over the string boundaries in case it's already too long. Reviewed-by: Luis Chamberlain Reviewed-by: Kees Cook Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20231120151419.1661807-3-andriy.shevchenko@linux.intel.com Signed-off-by: Kees Cook Stable-dep-of: 3dfaae04243c ("params: fix charp corruption on allocation failure") Signed-off-by: Sasha Levin --- kernel/params.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/params.c b/kernel/params.c index b904bd98dd01b..55541483d6d36 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -264,7 +264,10 @@ EXPORT_SYMBOL_GPL(param_set_uint_minmax); int param_set_charp(const char *val, const struct kernel_param *kp) { - if (strlen(val) > 1024) { + size_t len, maxlen = 1024; + + len = strnlen(val, maxlen + 1); + if (len == maxlen + 1) { pr_err("%s: string parameter too long\n", kp->name); return -ENOSPC; } @@ -274,7 +277,7 @@ int param_set_charp(const char *val, const struct kernel_param *kp) /* This is a hack. We can't kmalloc in early boot, and we * don't need to; this mangled commandline is preserved. */ if (slab_is_available()) { - *(char **)kp->arg = kmalloc_parameter(strlen(val)+1); + *(char **)kp->arg = kmalloc_parameter(len + 1); if (!*(char **)kp->arg) return -ENOMEM; strcpy(*(char **)kp->arg, val); @@ -512,7 +515,7 @@ int param_set_copystring(const char *val, const struct kernel_param *kp) { const struct kparam_string *kps = kp->str; - if (strlen(val)+1 > kps->maxlen) { + if (strnlen(val, kps->maxlen) == kps->maxlen) { pr_err("%s: string doesn't fit in %u chars.\n", kp->name, kps->maxlen-1); return -ENOSPC; -- 2.53.0