From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 97F23606A920 for ; Mon, 2 Nov 2026 14:25:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GZiOx3qz Received: by kanga.kvack.org (Postfix) id BF9AF6B05C8; Mon, 2 Nov 2026 09:25:06 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BD19C6B05C9; Mon, 2 Nov 2026 09:25:06 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B0E286B05CA; Mon, 2 Nov 2026 09:25:06 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 947736B05C8 for ; Mon, 2 Nov 2026 09:25:06 -0500 (EST) Received: from smtpin27.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 2F433120136 for ; Mon, 2 Nov 2026 14:25:06 +0000 (UTC) X-FDA: 85390401012.27.13A3E14 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf14.hostedemail.com (Postfix) with ESMTP id 5A6AE100006 for ; Mon, 2 Nov 2026 14:25:04 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=GZiOx3qz; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf14.hostedemail.com: domain of brauner@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=brauner@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793629504; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=yb3WLcVokXU6BuV8DQIS3cnoxrtkXR+HXTNSt4lhnr4=; b=sHBqtV6mtbqoslloKdq0Qbq+2Iwhrf0Sqh8MSSB7pX6E0OgDpeXFJVTBGtCbdb3GHGt+CD 6SXXPGsnd7VWY5miiEdNusqZjCbKKEnDWsHtg7XcxMBQbIZyYz2qL1LMTOMQykvI5TkGhl ggK6M4SAS+1Ffn4jWI1LgkTl/meMQCE= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=GZiOx3qz; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf14.hostedemail.com: domain of brauner@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=brauner@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793629504; b=8CBqPow275RBl+83Hfgn/3bnCTnkqHCEEC1cW6S3/4yhkiAsguxe+dlDD2miJH9RLzGKfG V4A4OmAtj1jgTgGzYPU9neNwmuipSVkKn4gxUbZnhmUm1KFNeOtm2lKeGpKla9E0n/NAhI +1AvweTchIwa0U5tRc9kZcIvc924NtQ= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 988FC41838; Mon, 2 Nov 2026 14:25:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 514531F00A16; Mon, 2 Nov 2026 14:24:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793629503; bh=yb3WLcVokXU6BuV8DQIS3cnoxrtkXR+HXTNSt4lhnr4=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=GZiOx3qz574i7G4sq7Qj5FW+poGzHx4xdod9v+c0wQs044ndbo8YtJuzjzz+Le7ql 5cTxXE9CzWg6EPV4MxszbcLp2C6ZsWzp9oeVP6uoHj7upUPwwroLqNsh41Sz3JVXM5 yckoX19xo0T3oBfUMO+m7+UdClsC4AicPeSVsnbkVWlzvS64GY4fx7NtE/3cBm/jGz ZM9+DG2Es/IdFoi9n/atozhLfqSzs42elqcEif/j8WN8Ox6UI8UdLXG/RdqSvOSB81 382CcANAMk/or+82KJJBXqoD4yYyV3R1x7/mjd7dPFt85mMcg0lpgdBZ0yY6v8VJOz OgF1Yl254onGQ== From: Christian Brauner Date: Mon, 02 Nov 2026 15:21:29 +0100 Subject: [PATCH RFC 14/38] um: NUL-terminate what is written to /proc/exitcode X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261102-work-procfs-bugfixes-v1-14-59422ed3e465@kernel.org> References: <20261102-work-procfs-bugfixes-v1-0-59422ed3e465@kernel.org> In-Reply-To: <20261102-work-procfs-bugfixes-v1-0-59422ed3e465@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , Jann Horn , Josef Bacik , Chris Mason , Jeff Layton , NeilBrown , Eric Dumazet , Thomas Gleixner , Al Viro , Jonathan Corbet , Christoph Hellwig , Greg Kroah-Hartman , Joel Granados , Kees Cook , Jan Kara , Jan Kara , linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-um@lists.infradead.org, linux-wireless@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, ntfs3@lists.linux.dev, platform-driver-x86@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, netfilter-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, ibm-acpi-devel@lists.sourceforge.net, jfs-discussion@lists.sourceforge.net, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cifs@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-mm@kvack.org, linux-sh@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, sparclinux@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-doc@vger.kernel.org, linux-serial@vger.kernel.org, linux-atm-general@lists.sourceforge.net, Takashi Iwai , linux-input@vger.kernel.org, linux-raid@vger.kernel.org, linux-ext4@vger.kernel.org, linux-modules@vger.kernel.org, linux-debuggers@vger.kernel.org, "Christian Brauner (Amutable)" , Chuck Lever , stable@vger.kernel.org X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1042; i=brauner@kernel.org; h=from:subject:message-id; bh=wRElBRQ5ywf1BhvCA77KtICLks8yyr6GFoKnZLCCyMo=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWS9mJOdsKVmvtvqn+l+CqJcqhVTz8/M753i1MLdtPdJz RS2GwlqHaUsDGJcDLJiiiwO7Sbhcst5KjYbZWrAzGFlAhnCwMUpABN5E8LI8LBw7tKUPiXhmasU BGdI++krPrfymz85hq3qxbk0wQO2RowMt9ZWzojz1tO+4XPUNkxeX7nqYWvpvKrUmfx7rnks+Nv HBQA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 X-Rspamd-Queue-Id: 5A6AE100006 X-Stat-Signature: kty6ysbhuqd8j7g1861tqchzjabg3ir3 X-Rspamd-Server: rspam04 X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=4.0.1 X-Rspam-User: X-HE-Tag: 1793629504-149361 X-HE-Meta: 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 SETwKtvZ LdbNrMDYugHJ2YZ9PCBPkWnJdVsKro/5uVRwm/ObzzG0MDLp0X6Lguw9U+jenn7oBbJ/8LACJpKvzNz7+bkrolWj57fUqPvqjNdxGPnk84NdAiU6zJJMtr6G3tzqQLuX65Ju2dvrgbtiix5pRGUWMHhAGcMzdFqlLU/EIVPjua5rd2z5PMY2rjfVwUIm9VXFdKozTEimfVKllAau7P5JzQ1Jn2mBoHRWH2cDltC47d9hmdr77m3W7L6XT9RGfHZgdGJi/ZvWWMIPFIaxAi8YmxsMUAy6sF5WA0RFF Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 exitcode_proc_write() copies up to sizeof(buf) bytes of the write into buf and hands it to simple_strtol() without terminating it. So "echo -n 5" parses whatever the stack held after the '5', and a write of seven bytes or more reads past the end of buf. Terminate the copy. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) --- arch/um/kernel/exitcode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/um/kernel/exitcode.c b/arch/um/kernel/exitcode.c index 43edc2aa57e4..0230354f4812 100644 --- a/arch/um/kernel/exitcode.c +++ b/arch/um/kernel/exitcode.c @@ -43,9 +43,10 @@ static ssize_t exitcode_proc_write(struct file *file, size_t size; int tmp; - size = min(count, sizeof(buf)); + size = min(count, sizeof(buf) - 1); if (copy_from_user(buf, buffer, size)) return -EFAULT; + buf[size] = '\0'; tmp = simple_strtol(buf, &end, 0); if ((*end != '\0') && !isspace(*end)) -- 2.53.0