From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 BD2D3459AD2; Fri, 9 Oct 2026 14:29:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791556159; cv=none; b=CIauiy7sbDhlns2vr+SKPVgV1b4pGJjzNBiDSZZ7h6CdBTrw804Ir8jULMko2vXiBMl+ymXo53V4jGOU7haxMi8kGYr0v0DSh8SccxFjqd3GrPkec1VO1PpILeiCO3rIwONVjJynIOaBLlJqX+28rNYTSptd+RtJnVWdxfDPyE4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791556159; c=relaxed/simple; bh=1JXfdlLRnyEvhAdKl8QagJySyyjTcanosb+OmGw1S3U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AZ1r3HFDp0E+AOCayZhPmo6sykUIflRs0yxxBXeWB2aCW3q1Y/xuirO7UM5AIN1YFbsYD4tTDh2zI49VuJJl2T2C3gr5j9uqen4HqMnWyfBH1+rjGmqiI1N4PcRpDNgqM6ox4YdlIaBjY94VuZQjPLVvVMpYsjzB63NtXdmXlTk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OLIYorta; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OLIYorta" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A27F1F00893; Fri, 9 Oct 2026 14:29:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791556158; bh=wzc+gXeVuaXESJ1wmJLCczDOwJv8PAzzCZI2MRUz1Ug=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=OLIYortac0itAa0y0tDGnMdPi7s2TRv1eVRCFXq1FFhGhs0omjsQ0aMikJz2JGDTg 6OvkUoA0steNU7muyYVW4TxEXFloNPQrLaCe4v2kLTK+P3Fblz8Jv3dBzpfyP01v6A mLxykDDR+fPtnwnXU7PoxrHfD7KM7CJin8r7o+44= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhaofeng Chen , Yuxiao Wang , Alexander Graf Subject: [PATCH 6.18 156/403] nitro_enclaves: fix use-after-free on SLOT_ALLOC failure Date: Fri, 9 Oct 2026 16:08:37 +0200 Message-ID: <20261009140955.722145272@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261009140952.119038291@linuxfoundation.org> References: <20261009140952.119038291@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yuxiao Wang commit 9bc184a2eda8b773c88ecbff934001ad649b9cc1 upstream. When ne_create_vm_ioctl() fails the SLOT_ALLOC request after anon_inode_getfile() has succeeded, the error path calls fput(enclave_file) and then frees ne_enclave. In normal userspace context, fput() defers the final __fput() via task_work. ne_enclave_release() therefore runs after ne_enclave has already been freed and dereferences ne_enclave->slot_uid, causing a use-after-free: KASAN: slab-use-after-free in ne_enclave_release. The enclave has no slot allocated and is not yet linked into the enclaves list on this error path, so ne_enclave_release() is expected to return early when slot_uid is zero. However, reading slot_uid already accesses the freed object. Clear enclave_file->private_data before fput() on the error path. ne_enclave_release() then returns immediately when private_data is NULL, leaving the ioctl error path as the sole owner of ne_enclave. This is safe because the file has not been fd_install()'d yet. Tested on an AWS EC2 m5.2xlarge with CONFIG_KASAN=y. Without the patch, the reproducer triggers a KASAN slab-use-after-free on every SLOT_ALLOC failure. With the patch, no KASAN report is produced and the SLOT_ALLOC error is still returned. Normal enclave creation and teardown are unaffected. Fixes: 9c8eb50fe9e2 ("nitro_enclaves: Add logic for terminating an enclave") Cc: stable@vger.kernel.org Co-developed-by: Zhaofeng Chen Signed-off-by: Zhaofeng Chen Signed-off-by: Yuxiao Wang Reviewed-by: Alexander Graf Link: https://patch.msgid.link/20260909124400.27857-1-graf@amazon.com Signed-off-by: Greg Kroah-Hartman --- drivers/virt/nitro_enclaves/ne_misc_dev.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/virt/nitro_enclaves/ne_misc_dev.c +++ b/drivers/virt/nitro_enclaves/ne_misc_dev.c @@ -1710,6 +1710,7 @@ static int ne_create_vm_ioctl(struct ne_ return enclave_fd; put_file: + enclave_file->private_data = NULL; fput(enclave_file); put_fd: put_unused_fd(enclave_fd);