From patchwork Tue Oct 17 20:11:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Stitt X-Patchwork-Id: 13425983 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 2E08E430E3 for ; Tue, 17 Oct 2023 20:11:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ZCuy4p31" Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C301C6FAC for ; Tue, 17 Oct 2023 13:11:30 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5a7a6fd18abso93618207b3.1 for ; Tue, 17 Oct 2023 13:11:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697573490; x=1698178290; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=Ui+yzBeCi4InBjuyJPgf+DR/WwQH9rt9/DWplSIMOHU=; b=ZCuy4p31X0jloLomlNs8XJvcVmD3ttbQZNyoTaVJtOPWzGnvcoBOUQ2e/4YMwqDivW pChbMBubGifg0+wkZkXMzdTiOKUuB2aHMAmxB/9Mv8KsYLbxxdet6YiS9GbpB9OwWGP+ sJ9MQKnRqO6kmkX16VHGXNBm/5FFiL5LcC/s7VEtw2d3fSgO08wVJjvOUoXGe3acumjv EkufxrbqH+2EIGEBN4qJjUPQvmH6LXMlXY/gUAso3wV6XIzldjhKz1I+tgIm3AbKrm/+ UZ2/G73GkTq6YTO+i+aw3ZLEmZZDdVslZk+qd691sC6QrCIlIg/kQrVi4wKYfOZuE0he fBVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697573490; x=1698178290; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Ui+yzBeCi4InBjuyJPgf+DR/WwQH9rt9/DWplSIMOHU=; b=R1jIVgm8IFK/f5ZkmUIci6Yf8dGcEJHmKjcQ5dLnD/0w7yMcMA+7e9rHg/XToHn14b w5zHpYsI7wOda9t/zp+N9OCJzhp9CEHrKdMgYnQtVPmRxndHH7O/ss79OXxODuAb/6f5 yZNWcUrhhrRLA0DVKz5qHelb2ZuVUp80tgb5smzDJvpHSjd1r/5pwsGEOlv058MZ4HfW iqmYKktMPv7rRoqy778LWb7JCEL0X3FQTKkcdOP0GWB+l4Uoz7IJXO1qQ+4bHPIIKHnh +9RujtwyjU5f5RR4M2ghnytsbfKVRworf7JOLOhw3NyhdtuWkdR40QujNL+qUwpbmJ6W m5jA== X-Gm-Message-State: AOJu0YwQJIvJnt5CEuEH1a6qXkA9gR/ezN8BHGkE7brfvcRRl5ZHp8eo 48Vwbs9LpmpmLyKhHDYUb7ISyLY/6fcdGQR7fw== X-Google-Smtp-Source: AGHT+IFdwSVFWDCbuxt9p23HfZYWm/J4eAdvM+BOXOvX8s65kb3vTO6keHsPW31fPGnVCQ1IRGQlfmNgVa+/ISopmw== X-Received: from jstitt-linux1.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:23b5]) (user=justinstitt job=sendgmr) by 2002:a05:6902:1346:b0:d9a:54e7:e910 with SMTP id g6-20020a056902134600b00d9a54e7e910mr71519ybu.4.1697573490059; Tue, 17 Oct 2023 13:11:30 -0700 (PDT) Date: Tue, 17 Oct 2023 20:11:28 +0000 In-Reply-To: <20231017-strncpy-drivers-net-wireless-broadcom-brcm80211-brcmfmac-cfg80211-c-v3-0-af780d74ae38@google.com> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231017-strncpy-drivers-net-wireless-broadcom-brcm80211-brcmfmac-cfg80211-c-v3-0-af780d74ae38@google.com> X-Developer-Key: i=justinstitt@google.com; a=ed25519; pk=tC3hNkJQTpNX/gLKxTNQKDmiQl6QjBNCGKJINqAdJsE= X-Developer-Signature: v=1; a=ed25519-sha256; t=1697573487; l=4966; i=justinstitt@google.com; s=20230717; h=from:subject:message-id; bh=gHDinb9a9sswIvj29QskOHXNeesA8YN3gdLsehwyx1o=; b=nAmbdGpBqSQNB9t1IYFTrpRaeC1QGXnuDgq0waS/15OL6TsrXeiVeYGUhvKYWMguhBQNEWYZk gJw9TTzVK+NDSiJlDVIqhgFT6x7JwDNKYduhIJHm8v3luvNPMUIb0OH X-Mailer: b4 0.12.3 Message-ID: <20231017-strncpy-drivers-net-wireless-broadcom-brcm80211-brcmfmac-cfg80211-c-v3-1-af780d74ae38@google.com> Subject: [PATCH v3 1/2] wifi: brcm80211: replace deprecated strncpy with strscpy From: Justin Stitt To: Arend van Spriel , Franky Lin , Hante Meuleman , Kalle Valo Cc: linux-wireless@vger.kernel.org, brcm80211-dev-list.pdl@broadcom.com, SHA-cyfmac-dev-list@infineon.com, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Justin Stitt X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Let's move away from using strncpy and instead favor a less ambiguous and more robust interface. For ifp->ndev->name, we expect ifp->ndev->name to be NUL-terminated based on its use in format strings within core.c: 67 | char *brcmf_ifname(struct brcmf_if *ifp) 68 | { 69 | if (!ifp) 70 | return ""; 71 | 72 | if (ifp->ndev) 73 | return ifp->ndev->name; 74 | 75 | return ""; 76 | } ... 288 | static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb, 289 | struct net_device *ndev) { ... 330 | brcmf_dbg(INFO, "%s: insufficient headroom (%d)\n", 331 | brcmf_ifname(ifp), head_delta); ... 336 | bphy_err(drvr, "%s: failed to expand headroom\n", 337 | brcmf_ifname(ifp)); For di->name, we expect di->name to be NUL-terminated based on its usage with format strings: | brcms_dbg_dma(di->core, | "%s: DMA64 tx doesn't have AE set\n", | di->name); Looking at its allocation we can see that it is already zero-allocated which means NUL-padding is not required: | di = kzalloc(sizeof(struct dma_info), GFP_ATOMIC); For wlc->modulecb[i].name, we expect each name in wlc->modulecb to be NUL-terminated based on their usage with strcmp(): | if (!strcmp(wlc->modulecb[i].name, name) && NUL-padding is not required as wlc is zero-allocated in: brcms_c_attach_malloc() -> | wlc = kzalloc(sizeof(struct brcms_c_info), GFP_ATOMIC); For all these cases, a suitable replacement is `strscpy` due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Signed-off-by: Justin Stitt Reviewed-by: Kees Cook --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 2 +- drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c | 2 +- drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c | 3 +-- drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c | 4 ++-- 4 files changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c index 2a90bb24ba77..7daa418df877 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c @@ -866,7 +866,7 @@ struct wireless_dev *brcmf_apsta_add_vif(struct wiphy *wiphy, const char *name, goto fail; } - strncpy(ifp->ndev->name, name, sizeof(ifp->ndev->name) - 1); + strscpy(ifp->ndev->name, name, sizeof(ifp->ndev->name)); err = brcmf_net_attach(ifp, true); if (err) { bphy_err(drvr, "Registering netdevice failed\n"); diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c index d4492d02e4ea..6e0c90f4718b 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c @@ -2334,7 +2334,7 @@ struct wireless_dev *brcmf_p2p_add_vif(struct wiphy *wiphy, const char *name, goto fail; } - strncpy(ifp->ndev->name, name, sizeof(ifp->ndev->name) - 1); + strscpy(ifp->ndev->name, name, sizeof(ifp->ndev->name)); ifp->ndev->name_assign_type = name_assign_type; err = brcmf_net_attach(ifp, true); if (err) { diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c index b7df576bb84d..3d5c1ef8f7f2 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c @@ -584,8 +584,7 @@ struct dma_pub *dma_attach(char *name, struct brcms_c_info *wlc, rxextheadroom, nrxpost, rxoffset, txregbase, rxregbase); /* make a private copy of our callers name */ - strncpy(di->name, name, MAXNAMEL); - di->name[MAXNAMEL - 1] = '\0'; + strscpy(di->name, name, sizeof(di->name)); di->dmadev = core->dma_dev; diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c index b3663c5ef382..34460b5815d0 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c @@ -5551,8 +5551,8 @@ int brcms_c_module_register(struct brcms_pub *pub, /* find an empty entry and just add, no duplication check! */ for (i = 0; i < BRCMS_MAXMODULES; i++) { if (wlc->modulecb[i].name[0] == '\0') { - strncpy(wlc->modulecb[i].name, name, - sizeof(wlc->modulecb[i].name) - 1); + strscpy(wlc->modulecb[i].name, name, + sizeof(wlc->modulecb[i].name)); wlc->modulecb[i].hdl = hdl; wlc->modulecb[i].down_fn = d_fn; return 0;