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 8F6FE22B8CF; Sun, 26 Jan 2025 15:05:10 +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=1737903910; cv=none; b=Me7hANabCjioMXX3t3AtUH4dr73Vpz2XffDGpTvIO1b5/niqhjt9VYbwIWMofl8FK+CXQB5HnoccJdYn/MAUX1P7zCh+Ga40aCdJ2rGICdYekE+dFaAk6TxB8nnWGF5r19llP3JI3/F5/vTRyFiVVjInabQp1KMESLxsZa6T2wM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737903910; c=relaxed/simple; bh=BoKVT25+FzNZDExRSFKExNoNJZeO5nsZ/vqkPeYVsCg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=npweapTrYdjyblnMVEw8nTb3Ae4e8OWgWm7ZVQKyL5ahWout+XaoUXEtxPfjlxo7xTeOknDl7GxN1gI3YIBmRp6fGkgektd9FVXYGEw/m5CC7lGSZTmaQGBRpbTYCgXnvleQzCVTB9LVXRbUIDG2N8V8u6AFhYPLAwKzPQVy/Go= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cgw+EAM6; 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="cgw+EAM6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 454F7C4CEE2; Sun, 26 Jan 2025 15:05:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737903910; bh=BoKVT25+FzNZDExRSFKExNoNJZeO5nsZ/vqkPeYVsCg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cgw+EAM6IEewmJjCBEFFh56iwjQAgEAwIQe9wMBAoVH+bzt2Z/nF629YhPZZpBdfE gJx58g5H9g5v1yl6HRh12gmeGI07nTuqUcKGK379B9whJJ2g3QX6fHbIZrBXxtzSZz 5ivA/7T0Dz9tvp+fFf5xbsrteWVG+VxWDnHs+U+6WjlMgkBafztzAUMk9VJj9QsTTs Y+mdQyCcSe+jvc1fW+bWwXh2PaoXxw/o/2qklePm98a3o6uwR3KcZrR1s6MPEYmr9o SiPNoqIvDIHJqSLQxeA5/IfYBuVzWhZBZ6169/tYeffV1WqxshpJ20Q0Xz+uhNJ0QK GOIbfc/ZYCCwQ== 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 5.10 04/12] tomoyo: don't emit warning in tomoyo_write_control() Date: Sun, 26 Jan 2025 10:04:52 -0500 Message-Id: <20250126150500.959521-4-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250126150500.959521-1-sashal@kernel.org> References: <20250126150500.959521-1-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 5.10.233 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 6235c3be832aa..e23993c784405 100644 --- a/security/tomoyo/common.c +++ b/security/tomoyo/common.c @@ -2673,7 +2673,7 @@ 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