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 A451012C48A; Tue, 30 Apr 2024 10:42:20 +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=1714473740; cv=none; b=qS0drZAa9Yj5gt2wDDWnQycdtk/57PLMqYBdjFcU/raeMpvttNl6S5BA8s2Keqj6Skd7uyC9R1pn6rRBvxwQWHKrzgtTrkXyQikqVIpKTHqDBw1azQk5QpxXHaFDjFUegcpZOFwZD7CaGENoWwk2I9AeS03VDcZ0i2I0eFyBHC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714473740; c=relaxed/simple; bh=E+a2QE0kn3K/1BSQ8PuJwvNGh0gC4jTaKnVZIg2y5PY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e6ib4b0nUikHDLMK8/WE8iLRhczWCDjcaw0uPmS6PZe3Sr2MvhRi9+pjIe5ft/eO/5PNHIXFFgDluUUjnX8rMvP3iV/IldRkcfMaWL9b51+54msAB7gO/uzfC3lEuGKT+Je9kD8ZpQKsnvgAssy9z2t6IkgitZhi6R5NkWrc99Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AU4Tfy1p; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="AU4Tfy1p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8DA0C2BBFC; Tue, 30 Apr 2024 10:42:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1714473740; bh=E+a2QE0kn3K/1BSQ8PuJwvNGh0gC4jTaKnVZIg2y5PY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AU4Tfy1pkkWZpyYuYrr2qiTaPrI+YBi4i5XKSnYMdMNNGNkCBwuEBCl1ChH6s4o9H mcou4S7KrFoXLKdhudcqD1R4ARqXeh/n2c43jHFpUP4M04+qj+c7v2/crwSOqXPOY6 4juob7U5T+G+f6L6gA/5i3IZW9E/rgJ59zK9Y9VY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zheng Yejian , "Masami Hiramatsu (Google)" Subject: [PATCH 4.19 15/77] kprobes: Fix possible use-after-free issue on kprobe registration Date: Tue, 30 Apr 2024 12:38:54 +0200 Message-ID: <20240430103041.573798401@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240430103041.111219002@linuxfoundation.org> References: <20240430103041.111219002@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zheng Yejian commit 325f3fb551f8cd672dbbfc4cf58b14f9ee3fc9e8 upstream. When unloading a module, its state is changing MODULE_STATE_LIVE -> MODULE_STATE_GOING -> MODULE_STATE_UNFORMED. Each change will take a time. `is_module_text_address()` and `__module_text_address()` works with MODULE_STATE_LIVE and MODULE_STATE_GOING. If we use `is_module_text_address()` and `__module_text_address()` separately, there is a chance that the first one is succeeded but the next one is failed because module->state becomes MODULE_STATE_UNFORMED between those operations. In `check_kprobe_address_safe()`, if the second `__module_text_address()` is failed, that is ignored because it expected a kernel_text address. But it may have failed simply because module->state has been changed to MODULE_STATE_UNFORMED. In this case, arm_kprobe() will try to modify non-exist module text address (use-after-free). To fix this problem, we should not use separated `is_module_text_address()` and `__module_text_address()`, but use only `__module_text_address()` once and do `try_module_get(module)` which is only available with MODULE_STATE_LIVE. Link: https://lore.kernel.org/all/20240410015802.265220-1-zhengyejian1@huawei.com/ Fixes: 28f6c37a2910 ("kprobes: Forbid probing on trampoline and BPF code areas") Cc: stable@vger.kernel.org Signed-off-by: Zheng Yejian Signed-off-by: Masami Hiramatsu (Google) [Fix conflict due to lack dependency commit 223a76b268c9 ("kprobes: Fix coding style issues")] Signed-off-by: Zheng Yejian Signed-off-by: Greg Kroah-Hartman --- kernel/kprobes.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1565,10 +1565,17 @@ static int check_kprobe_address_safe(str jump_label_lock(); preempt_disable(); - /* Ensure it is not in reserved area nor out of text */ - if (!(core_kernel_text((unsigned long) p->addr) || - is_module_text_address((unsigned long) p->addr)) || - in_gate_area_no_mm((unsigned long) p->addr) || + /* Ensure the address is in a text area, and find a module if exists. */ + *probed_mod = NULL; + if (!core_kernel_text((unsigned long) p->addr)) { + *probed_mod = __module_text_address((unsigned long) p->addr); + if (!(*probed_mod)) { + ret = -EINVAL; + goto out; + } + } + /* Ensure it is not in reserved area. */ + if (in_gate_area_no_mm((unsigned long) p->addr) || within_kprobe_blacklist((unsigned long) p->addr) || jump_label_text_reserved(p->addr, p->addr) || find_bug((unsigned long)p->addr)) { @@ -1576,8 +1583,7 @@ static int check_kprobe_address_safe(str goto out; } - /* Check if are we probing a module */ - *probed_mod = __module_text_address((unsigned long) p->addr); + /* Get module refcount and reject __init functions for loaded modules. */ if (*probed_mod) { /* * We must hold a refcount of the probed module while updating