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 263941F0E34; Sun, 26 Jan 2025 15:04:04 +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=1737903845; cv=none; b=Dapn6vTEkfxaRPrqNQFS8tdq5vGwqcfurz5TKUQJZNIomSppNQkxNZtojLUo/oF6jfbZJ6p7gKDL36wAZzhbxmbrXJdNFzJRH0Szg4Y0qQSwLZRwd6L370R3lHZHfU6AD3XnK/1dZJYvkNk5HAZJ79guBKOj+Yn1Zz2sQe9SW8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737903845; c=relaxed/simple; bh=IkGoTTiRdnPoF9wVFpahtJe9erV3z8jlR8dEmiSN/OA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=fEiUu6AHH2EbQZ1sCDpuIWKbICdDDAeHRV1baacSe8CioihXcpyRdi17QuYeXO7YYNfpcPYX8wRoZhe9GwojiOuI4NeCwHtT6k1i9KW6hC98tozFUbygjOuu/A+Q39OskEjPmbdKdBhw3MoCmgGhvDc2QEWegijzw9TcTmHrgMY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AFGBxADB; 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="AFGBxADB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A83CC4CEE5; Sun, 26 Jan 2025 15:04:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737903844; bh=IkGoTTiRdnPoF9wVFpahtJe9erV3z8jlR8dEmiSN/OA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AFGBxADBZsl7rmwMJu3tOcaOJA0yAaoICFizFEC2j5Bv/4JCGvGBpyTf3Iqjz24rt tNtVU6qrkyGfVQMjXXfMgRA6qPBo3YgYQSxd/f5/tjNGtqfG5owaL4ioD9owImR6a0 gfdAmbvfsNRxfH+oT8sLYxaxh1OKFgrgbUfhuxhMnOZT3U0SXoXu9Jn8E0qPc3rW7c TQ8UsX/JZMcvSl8VSU7W8KUvMDgHhh1fEvnqbpDDBItS1+maCU6n9lyp8g/o7Dvcsf rxtQ33azE1+fU7P7BFl4ga9snpAXw2CQhgeQ7fyyc07JOnYvPc2PdLx86YKJtVrwdZ a1GXYOwfHmhBg== 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 6.1 05/17] tomoyo: don't emit warning in tomoyo_write_control() Date: Sun, 26 Jan 2025 10:03:41 -0500 Message-Id: <20250126150353.957794-5-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250126150353.957794-1-sashal@kernel.org> References: <20250126150353.957794-1-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 6.1.127 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 a7af085550b2d..5f1cdd0af115d 100644 --- a/security/tomoyo/common.c +++ b/security/tomoyo/common.c @@ -2664,7 +2664,7 @@ 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