From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49F54C433FE for ; Tue, 11 Oct 2022 06:52:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229868AbiJKGwx (ORCPT ); Tue, 11 Oct 2022 02:52:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229499AbiJKGws (ORCPT ); Tue, 11 Oct 2022 02:52:48 -0400 Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A963280F5E for ; Mon, 10 Oct 2022 23:52:46 -0700 (PDT) Received: by mail-pf1-x42f.google.com with SMTP id 204so12681768pfx.10 for ; Mon, 10 Oct 2022 23:52:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=IhQCr2/mj1To+oAjfcYwW5DtgdU/tRz+Z1vgx/smBpw=; b=EIoaKf6Yioci3SpU35lj7pBWNJWY29BnptxpIevAzLWRb0fMQXSAVg9RZeBejpc3b/ K6wswV5lkxcUX4noYIDUBvyRvXOK6DPTR/4tj1vT3l3HGO5FM2HjorhVjmt6xdSWwky9 uMqRZskWt17tEX3HrKN2vJQhvQ2SrbWzknXc0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=IhQCr2/mj1To+oAjfcYwW5DtgdU/tRz+Z1vgx/smBpw=; b=zg/IwBXFw8nlt8ZesDfrLrsQdf1jvM5Lyh83bAADSYQeRKfJaIP/5+zpvvT1Bml92v de8iZUaJV4DbZv1SJRsiz/kW2PXkxqG8EOnxxAc/sDqzhG1DQTKbwAEPg8uqdTHIBby4 FHDCGM2Lc7R6wT9aJk3vbb0VQRQ+TJKD1fQiaCtryYAyZwFjTofRwmmppGdLPfFjRs8X nQr7vSHCkiuvJYPpwH5Zp1GNM/6ajWqroBChEA5eZLt1p9qe7YabzxHKIfX2xDHMhEH/ 2YFr/GaNExORr0V67k2WhXeG48vVcloM7bx8rGqXqBYXLBiqY6Ykcs5hbHx6cYsJ7HJE 6VBg== X-Gm-Message-State: ACrzQf3YxrrJpF2LMKyhYWYw7ykgklCp/un7YHAuhRiYTKFtgUTHj7JG qNVj9A9L461YhZLCj2mKX5t+0A== X-Google-Smtp-Source: AMsMyM6Kqhfv3NRPyt5rnHl2Q1aXOBuD+1vkAjs24JUi0+hR4+9li1k2ug5+2Md9Hy66LdAUpxUW6w== X-Received: by 2002:a05:6a00:e1b:b0:537:7c74:c405 with SMTP id bq27-20020a056a000e1b00b005377c74c405mr23253507pfb.43.1665471166164; Mon, 10 Oct 2022 23:52:46 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id n12-20020a170902e54c00b0017ca9f4d22fsm7812359plf.209.2022.10.10.23.52.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Oct 2022 23:52:45 -0700 (PDT) From: Kees Cook To: Trond Myklebust Cc: Kees Cook , kernel test robot , Anna Schumaker , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] NFS: Avoid memcpy() run-time warning for struct sockaddr overflows Date: Mon, 10 Oct 2022 23:52:43 -0700 Message-Id: <20221011065243.583650-1-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3123; h=from:subject; bh=jFWeG4mKZjaCTmVttsBT+shSjRAcSAR+gkBCMpwmSmY=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBjRRK7yqXTcuhapb8wt0RJRmg09UAG/TKO7oglxRdW fUaVX0eJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCY0USuwAKCRCJcvTf3G3AJvslD/ 9rMzqrDJsGp2lh6GKEvBs28bCjDeXE2T7Cxi/kcY7Ig0nB2jUPlBR154A5lHiv13nNOwzwYRI8KyzS EY4dr1JmOCtv+YV8friFXHDCl/XZH/sgm5ZORmxYe6eOhEtirlIUrtNX6L2H7OQaEZNJaxs95oTIcn YbVhs1hld/dcMc59jYatSH3UvFuxEtJuyYnSRrOShtEswSY7LN0JOlH4A/obtgk/TMuUAaPoSz5AGp 1eKqmPrd+J5xsxjSBgtpMai2oXbOCNGPKl32MVK4dtw+6q/TrOQefDa2Vuzyjiw/jQKyUPXCjkIaku uo+eA0VlKL38fsrRvDCWq/cnmMPLEhrhnre7qxrUPdXACIy/wmnDK/k0fyv89RZsJDM9mUris0UeQh 2K4j8XalOzH/JRH1fCx18YAEmk1S++Np4r+JZcljnvMTZxMQlbeBkGsC15XIbrnBKZHPn/zG/HVW6n ze9+P+Cw8kHf70qSXdAhM05uuXIPOCA1sWdgyj+dPDBO+e9y83MomkH2GLt+5M8fXvH2R52BwsRVyt Rf4KB0xdwYx411OgsdlBB7xBIHvxsZu7ifi9sism/ahCDpaE+IKFQofw2dadbmqQWO3hQU+oBCktaV uyC7fxejf/vGiBTuy7wdoKunj/0T2Z3k1r/qZvsT7MupKRZ3/hClJhm5HQFQ== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The 'nfs_server' and 'mount_server' structures include a union of 'struct sockaddr' (with the older 16 bytes max address size) and 'struct sockaddr_storage' which is large enough to hold all the supported sa_family types (128 bytes max size). The runtime memcpy() buffer overflow checker is seeing attempts to write beyond the 16 bytes as an overflow, but the actual expected size is that of 'struct sockaddr_storage'. Adjust the pointers to the correct union member. Avoids this false positive run-time warning under CONFIG_FORTIFY_SOURCE: memcpy: detected field-spanning write (size 28) of single field "&ctx->nfs_server.address" at fs/nfs/namespace.c:178 (size 16) Reported-by: kernel test robot Link: https://lore.kernel.org/all/202210110948.26b43120-yujie.liu@intel.com Cc: Trond Myklebust Cc: Anna Schumaker Cc: linux-nfs@vger.kernel.org Signed-off-by: Kees Cook --- fs/nfs/fs_context.c | 2 +- fs/nfs/namespace.c | 2 +- fs/nfs/super.c | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c index 4da701fd1424..bffa31bb35b9 100644 --- a/fs/nfs/fs_context.c +++ b/fs/nfs/fs_context.c @@ -1540,7 +1540,7 @@ static int nfs_init_fs_context(struct fs_context *fc) ctx->version = nfss->nfs_client->rpc_ops->version; ctx->minorversion = nfss->nfs_client->cl_minorversion; - memcpy(&ctx->nfs_server.address, &nfss->nfs_client->cl_addr, + memcpy(&ctx->nfs_server._address, &nfss->nfs_client->cl_addr, ctx->nfs_server.addrlen); if (fc->net_ns != net) { diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c index 3295af4110f1..2f336ace7555 100644 --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -175,7 +175,7 @@ struct vfsmount *nfs_d_automount(struct path *path) } /* for submounts we want the same server; referrals will reassign */ - memcpy(&ctx->nfs_server.address, &client->cl_addr, client->cl_addrlen); + memcpy(&ctx->nfs_server._address, &client->cl_addr, client->cl_addrlen); ctx->nfs_server.addrlen = client->cl_addrlen; ctx->nfs_server.port = server->port; diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 82944e14fcea..8ea7dfdea427 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -823,7 +823,7 @@ static int nfs_request_mount(struct fs_context *fc, struct nfs_fs_context *ctx = nfs_fc2context(fc); struct nfs_mount_request request = { .sap = (struct sockaddr *) - &ctx->mount_server.address, + &ctx->mount_server._address, .dirpath = ctx->nfs_server.export_path, .protocol = ctx->mount_server.protocol, .fh = root_fh, @@ -854,7 +854,7 @@ static int nfs_request_mount(struct fs_context *fc, * Construct the mount server's address. */ if (ctx->mount_server.address.sa_family == AF_UNSPEC) { - memcpy(request.sap, &ctx->nfs_server.address, + memcpy(request.sap, &ctx->nfs_server._address, ctx->nfs_server.addrlen); ctx->mount_server.addrlen = ctx->nfs_server.addrlen; } -- 2.34.1