From mboxrd@z Thu Jan 1 00:00:00 1970 From: Romain Perier Subject: [PATCH 01/20] cgroup: Manual replacement of the deprecated strlcpy() with return values Date: Mon, 22 Feb 2021 16:12:12 +0100 Message-ID: <20210222151231.22572-2-romain.perier@gmail.com> References: <20210222151231.22572-1-romain.perier@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=P+jxf/c6aKxBtKoS9ZDFkjl+nA7mB7wt86sqHcoIgnU=; b=Igj+NEPkPWJoijrkRrH/caY1E5NfYkZDCZBhzVHmscEXfl+nAU78Fds4ChKT5iDrNC 3Re67QcqVO7PVhLnnkmbHNIeb4QyzO5LpMQ4CZh3L5ljZOXZ9UxWRynfgTwVM+sUAJz5 klfGDgvY+/fw5TX3ymZqTbgFogQvObV/nXFCkcasHwi372vovAHjSr/7Kasiuj3uHNm+ jYyltTXRnnMePNacdNKWXGIGVEiOdKvLF5ZfEGDiQsT7/511k9S7wlrFXMT5o10kLEz1 AUdPF2xJqw9I/8FJ1VAcA1OHMF/rlP127zcAuRQ/pTd7Nj+AR1jK/ld7mx5nqdHC6ElF QPKg== In-Reply-To: <20210222151231.22572-1-romain.perier@gmail.com> Content-Type: text/plain; charset="us-ascii" To: Kees Cook , kernel-hardening@lists.openwall.com, Tejun Heo , Zefan Li , Johannes Weiner Cc: Romain Perier , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org The strlcpy() reads the entire source buffer first, it is dangerous if the source buffer lenght is unbounded or possibility non NULL-terminated. It can lead to linear read overflows, crashes, etc... As recommended in the deprecated interfaces [1], it should be replaced by strscpy. This commit replaces all calls to strlcpy that handle the return values by the corresponding strscpy calls with new handling of the return values (as it is quite different between the two functions). [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy Signed-off-by: Romain Perier --- kernel/cgroup/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 1ea995f801ec..bac0dc2ff8ad 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2265,7 +2265,7 @@ int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen) ret = cgroup_path_ns_locked(cgrp, buf, buflen, &init_cgroup_ns); } else { /* if no hierarchy exists, everyone is in "/" */ - ret = strlcpy(buf, "/", buflen); + ret = strscpy(buf, "/", buflen); } spin_unlock_irq(&css_set_lock);