From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE47829BDB5; Sat, 17 Oct 2026 16:52:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792255924; cv=none; b=ai1eG9PmOrl8e030uSfZyAMGTTp8lyM6cyXi2oKb6oFEQtWPcJgG93udw8Ne/fNp5mILrr6ClXMOeUYXIfPVk7jFWEoO045GZcX0fPwIyL4guCNiB7/OGO1dadZn5xE7+Ig0XZwmWLpcF0JwKnQK2f9M1aoC1fYkiCPc0sHI5VM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792255924; c=relaxed/simple; bh=5SlxkSBxDv7fNNLFeSoLzoAIc6YwqFBnA9+7BV2fQR8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Y5Ngl/UgSedOZ2wzcan3hzAnsfByBuZVGdJz05pomwqAdEyediReauFyO1mXSfGaFfj+N04tB1fNfJU+ChSZF2QndT8YM9u2pEcHHAae8NZx+gtsYXolw9BgTcksNJBZ105NW1dxIcRJcjH6Wmd/TzkUJPXwNodE7elgdKAZyeE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JSovLMBJ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JSovLMBJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35DDD1F000C4; Sat, 17 Oct 2026 16:52:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792255923; bh=bxVb3inmj0zUDbKJLHetA1ntmclQrj7jHB8lt9ZDbeA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JSovLMBJnMDNR6A6KyfuOiyBqNCipnv46xc4MJxJccpDy3j7r4r+VFOcUCO/WK5He 2/0F+G3TmvK1WCYx82PF/u9X281ulSdXrazdGfcQzdpFMbVcUViZiz4yoHnhSAdGsB OOBncF5HEOZutMfU5xaHCSNF+RrzQEeRgzXrGPf8= 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 6.6 0064/1674] params: Do not go over the limit when getting the string length Date: Sat, 17 Oct 2026 17:38:56 +0200 Message-ID: <20261017160432.782400717@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160431.119607952@linuxfoundation.org> References: <20261017160431.119607952@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-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 9d09ea99363fc..8992899996984 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