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 550F280049; Mon, 15 Apr 2024 14:36:43 +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=1713191803; cv=none; b=qtH4d5NhYoY5yWsqmkyDV4Za3E/oW4KeG1jK/KQYvedMeMXq28sH3CNPXTXrGmFYQ2UXZ3HV4ymmq5yJKX3+xfCCUhv7KLlz+CbcN18xZOfQs0CEvCEuVAUVpyExAc6VdJ68hsqOIGPBLeUdQ0jfghdMpXcF5EOq/wcMeD+0a9g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713191803; c=relaxed/simple; bh=51LfCQq6MQFoTopwWRpgrVlBAq89i3ugg3e1b31Effk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aJrNGNA3GLsStT4X5UTj0NTqNJihSeU4WKzMTNVQwhahepDfd2zV7muPdj2hD5icdWrcCLBU7uRPnvjuHz9clUw6jhMJlCb62B6mFg38Xj15l0agAJz0zoPHSjdMNnbkj7FYXtdEL3e7x5ktcwCJ4QPrsfFRh/NNg+3mPV0P6kQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=o/IlgENr; 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="o/IlgENr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CEEA6C113CC; Mon, 15 Apr 2024 14:36:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1713191803; bh=51LfCQq6MQFoTopwWRpgrVlBAq89i3ugg3e1b31Effk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o/IlgENrGAxulRBI+6MYebXrlqSdN1BOGJSv3IfQmGS6FoJ8qMC34Dr1a6a8gu7ac gV/GL1Tu227TIbc2Jr7NZkYPspQZkZFuKAoVOOXokWzcuY6Y9mDK0NDZDmKReirLfR PkgEtuJgIPaec+OSSXn5qGFIHOLaSTejM2OV0CY8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zheng Yejian , "Masami Hiramatsu (Google)" Subject: [PATCH 6.6 084/122] kprobes: Fix possible use-after-free issue on kprobe registration Date: Mon, 15 Apr 2024 16:20:49 +0200 Message-ID: <20240415141955.897520572@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240415141953.365222063@linuxfoundation.org> References: <20240415141953.365222063@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 6.6-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) 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 @@ -1567,10 +1567,17 @@ 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) || static_call_text_reserved(p->addr, p->addr) || @@ -1580,8 +1587,7 @@ static int check_kprobe_address_safe(str goto out; } - /* Check if 'p' is 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