From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E672E22F3BB; Sun, 26 Jan 2025 15:05:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737903937; cv=none; b=DY1h1vDywphjZimyPfPL7VUylZY0WybLliE83TvWV5gnJkGEDqgNndxs4S/adxZYs33jzeTCSMhfouGRb1iS8hZwL37lsB+mJIPBsiLISZiLLyigPWB8qx7DtlXfTK7jITaBuKlnbHQVQYz8jM8izd1mFSyARnSfAU0TROYwRVE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737903937; c=relaxed/simple; bh=coDBjQYCJdMJ8RoSlZOh9725+pb/7qsNmTV+zBP9iiI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=OFcjake9sJsrXioPWtHoExhO7qriS9laWi82RGjQGtKj3ZjdT09yP9+j5hJuzjBV1208rtV2nLCdS6Z5QZBtx8pYnjRDWorSxjFEXO3ig16e/hhyFkHl5qukj2KOcRiriYYGfw2GDPsjmeygOCZoYLPiWe8Yuo+6fUkwT8q7M6U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W1btQN2A; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="W1btQN2A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98F9FC4CEE2; Sun, 26 Jan 2025 15:05:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737903936; bh=coDBjQYCJdMJ8RoSlZOh9725+pb/7qsNmTV+zBP9iiI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W1btQN2AIaNwkJzpCF097LbVGddWDJt98/QLd5VRGsUZzIHHHwAx+hdT6Ph++QL6K dYhJXpX7boM9tGOhBa9gEllXlNU/PPP245aJ61+5QwvAFnxby5OjpFkjdyt9jb9yZP VwOwM+UIvw3GjxqGeWpa17WqfrkRWEHd5G+alyOjKdaM0jaCkiHcc+OI4ktHsUxIiK xDy4W7uVVm+dohUUHsizPCb6XnvLcMxZ+UkR/OgsQqsH+qgb35SlzfjU/JL4OQsnrY x18h3LMXeg/vSbOtkn2J6A6E8PViem1ILt4PV/K0Di2FLR5K8Q1zICZDnrTAAUnghf z0BxM9YMSnS5g== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tetsuo Handa , syzbot+7536f77535e5210a5c76@syzkaller.appspotmail.com, Leo Stone , Sasha Levin , takedakn@nttdata.co.jp, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, linux-security-module@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 4/7] tomoyo: don't emit warning in tomoyo_write_control() Date: Sun, 26 Jan 2025 10:05:24 -0500 Message-Id: <20250126150527.960265-4-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250126150527.960265-1-sashal@kernel.org> References: <20250126150527.960265-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.4.289 Content-Transfer-Encoding: 8bit From: Tetsuo Handa [ Upstream commit 3df7546fc03b8f004eee0b9e3256369f7d096685 ] syzbot is reporting too large allocation warning at tomoyo_write_control(), for one can write a very very long line without new line character. To fix this warning, I use __GFP_NOWARN rather than checking for KMALLOC_MAX_SIZE, for practically a valid line should be always shorter than 32KB where the "too small to fail" memory-allocation rule applies. One might try to write a valid line that is longer than 32KB, but such request will likely fail with -ENOMEM. Therefore, I feel that separately returning -EINVAL when a line is longer than KMALLOC_MAX_SIZE is redundant. There is no need to distinguish over-32KB and over-KMALLOC_MAX_SIZE. Reported-by: syzbot+7536f77535e5210a5c76@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7536f77535e5210a5c76 Reported-by: Leo Stone Closes: https://lkml.kernel.org/r/20241216021459.178759-2-leocstone@gmail.com Signed-off-by: Tetsuo Handa Signed-off-by: Sasha Levin --- security/tomoyo/common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c index 1b467381986f7..360cf2960f349 100644 --- a/security/tomoyo/common.c +++ b/security/tomoyo/common.c @@ -2674,7 +2674,7 @@ ssize_t tomoyo_write_control(struct tomoyo_io_buffer *head, if (head->w.avail >= head->writebuf_size - 1) { const int len = head->writebuf_size * 2; - char *cp = kzalloc(len, GFP_NOFS); + char *cp = kzalloc(len, GFP_NOFS | __GFP_NOWARN); if (!cp) { error = -ENOMEM; -- 2.39.5