From patchwork Wed Feb 21 23:50:26 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Stitt X-Patchwork-Id: 774795 Received: from mail-io1-f74.google.com (mail-io1-f74.google.com [209.85.166.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D30012D74E for ; Wed, 21 Feb 2024 23:50:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708559436; cv=none; b=RYhnJdd8eDOi43nuAv8rlm2BxnpQMqN0TLTL6sl1+zxrRbgzuT2XGVQdVatqD2KXX7VCcZdxO1nuBGTDqych5vVYjU2gD91DtH2iTiVjzp20EuYrprBzdMEhrkGYuagxvvhL2+3M8autqNQc3sFn1o263G9ZV5aho94BWFwc37g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708559436; c=relaxed/simple; bh=nCnAH6swIp2emDmvgeIyHlmnszZXY52TNqt+AplJKBU=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=nUB5AeLYvHAA/PPKvyups4Yoc3qYt6ALaMg6aIOmzf47amP1+d9bK9H8OO+WDG0T0sDr0E2f3zZZrTaV+/mBzqTAl4rW/1NcUrCdFXx49z1gI/T8SRuYmBmndMQ1FqLU/tHD+l2eCUVJZO8/g5HqZZaPszAiwmZibiFXBfoGppE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--justinstitt.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=KrP1JFmG; arc=none smtp.client-ip=209.85.166.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--justinstitt.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="KrP1JFmG" Received: by mail-io1-f74.google.com with SMTP id ca18e2360f4ac-7bc2b7bef65so556270939f.0 for ; Wed, 21 Feb 2024 15:50:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1708559433; x=1709164233; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=9ssJhSw8IGwkaMJQVHXTzvwEqUpaKWRubYumbO3rYIY=; b=KrP1JFmGDzB6sYKRBjS2UDmFA+IO3Y/u1eRKNJvGNeMdIrgNRM8TN6+Y8zp75bzVhj B1ifaVUKk26IyQ70/QrmlpXekFFbyBLSUz9EtCsKrWH/1y9RdvP4OXKzgKqK36xdXDUP hEFD3mB4GNyve3kGNWS6VPEjyI2aQYhFmdH/S+L2VGRR3X/dbRfvvXGSYA2+gBZn9/bh WOZIBKAzLeHY9stIwuqywNqbF9jAt4cFRwf6XK2jAC4vYlLLhFpUTCeUXoNsegfEZMQa fs3GsNMGnmkxPKU2PSzrPzH0HIol1cplUgL2T/Hd6i8SJpQBBxnjIIuB/soW0Q3tVTpY iOjw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708559433; x=1709164233; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=9ssJhSw8IGwkaMJQVHXTzvwEqUpaKWRubYumbO3rYIY=; b=gDy6eyOl/Lzt1lqke3aJvBKZi0diF2lRLOG5KWI0YOmUhh6iuQf4Sp/fE26PBtJ0te 0GOScEm9FRUngE/qaeB1Hr3qubLZxsEdYZCAV2Bsie25cVowvjW7GugBz2hT7vdM6erz j8CtRmCnzzkWBwn+Ib7s45aYDwGmB7TRBCTK1dq35Zr6u4/7E/yxdtTi187YNDR4d8mt 56irFV8cq+00AhYdaTBy+ymJ00GV90bgpx8iXgCiEed5oq7sAvwJ4WZWc7rNhQUVdrmw DEVuRZID6hfYzJGunfbugobYwGYhPWQHcK7b9NBDre81oTS3rNOXWtvyVL2xN/QgD+nb QWVg== X-Gm-Message-State: AOJu0YzWS0o76fk9QjZmPjG+L9Dbsdbz9CcNqTnjII0qzFNwULD7PHp2 Og2akP4XVqFRYkgrKEkHULK7OU+2Hc/ccX6XX6fEjBshxjy1ouJ5PyTtF/E0NhxS/rZHGqg5mvh vQbWa5tt5gQ33N4YrDfbYRA== X-Google-Smtp-Source: AGHT+IG5ImoOOYrjTV0m32TYWgADsPNmLYkMxOSs1mejSOYPrWlYHpAKSaT8TD6C8T1PZlMxpmL7/QPdxp6muuzRAw== X-Received: from jstitt-linux1.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:23b5]) (user=justinstitt job=sendgmr) by 2002:a05:6638:4816:b0:473:db4c:6fee with SMTP id cp22-20020a056638481600b00473db4c6feemr258770jab.2.1708559433547; Wed, 21 Feb 2024 15:50:33 -0800 (PST) Date: Wed, 21 Feb 2024 23:50:26 +0000 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAEKM1mUC/5XNQQ6CMBCF4auYrh3TlkjElfcwxMB0CpNgSzqkk RDubuUGLv+3eN+mhBKTqPtpU4kyC8dQwp5PCscuDATsSiurbWV0pUGWFHBewSXOlAQEhWHi3iN 4fFHA6AhGuHauto2vHTWoytmcyPPngJ5t6ZFliWk93Gx+699ENmAA9Q1tT3VPvnsMMQ4TXTC+V bvv+xdwNLBk3QAAAA== X-Developer-Key: i=justinstitt@google.com; a=ed25519; pk=tC3hNkJQTpNX/gLKxTNQKDmiQl6QjBNCGKJINqAdJsE= X-Developer-Signature: v=1; a=ed25519-sha256; t=1708559432; l=3137; i=justinstitt@google.com; s=20230717; h=from:subject:message-id; bh=nCnAH6swIp2emDmvgeIyHlmnszZXY52TNqt+AplJKBU=; b=bjMp/bqaxulF7lV6pQWdDcIpAYH60nRPQcPkZG4591ITeaNSRX3DtgWjl3k2UaEs+KaDivfR7 EcPs9LYT7eEDFnxN6eg3DcMXbgVbATIzxG+6ZUP+fKcJsahijSMAmo7 X-Mailer: b4 0.12.3 Message-ID: <20240221-strncpy-drivers-scsi-libfc-fc_encode-h-v2-1-019a0889c5ca@google.com> Subject: [PATCH v2] scsi: libfc: replace deprecated strncpy with memcpy From: Justin Stitt To: Hannes Reinecke , "James E.J. Bottomley" , "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Justin Stitt strncpy() is deprecated [1] and as such we should use different apis to copy string data. We can see that ct is NUL-initialized with fc_ct_hdr_fill: | ct = fc_ct_hdr_fill(fp, op, sizeof(struct fc_ns_rspn) + len, ... In fc_ct_hdr_fill(): | memset(ct, 0, ct_plen); We also calculate the length of the source string: | len = strnlen(fc_host_symbolic_name(lport->host), 255); ...then this argument is used in strncpy(), which is bad because the pattern of (dest, src, strlen(src)) usually leaves the destination buffer without NUL-termination. However, it looks as though we do not require NUL-termination since fr_name is part of a seq_buf-like structure wherein its length is monitored: | struct fc_ns_rspn { | struct fc_ns_fid fr_fid; /* port ID object */ | __u8 fr_name_len; | char fr_name[]; | } __attribute__((__packed__)); So, this is really just a byte copy into a length-bounded buffer. Let's use memcpy(). Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Reviewed-by: Kees Cook --- Changes in v2: - Don't mark fields with __nonstring - Link to v1: https://lore.kernel.org/r/20231030-strncpy-drivers-scsi-libfc-fc_encode-h-v1-1-c08c2be6befa@google.com --- drivers/scsi/libfc/fc_encode.h | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- base-commit: 517bc069e3eaad84d879101e0351ca7783243b32 change-id: 20231030-strncpy-drivers-scsi-libfc-fc_encode-h-5ad629f6de9c Best regards, -- Justin Stitt diff --git a/drivers/scsi/libfc/fc_encode.h b/drivers/scsi/libfc/fc_encode.h index 7dcac3b6baa7..6b7e4ca6b7b5 100644 --- a/drivers/scsi/libfc/fc_encode.h +++ b/drivers/scsi/libfc/fc_encode.h @@ -136,22 +136,24 @@ static inline int fc_ct_ns_fill(struct fc_lport *lport, break; case FC_NS_RSPN_ID: - len = strnlen(fc_host_symbolic_name(lport->host), 255); + len = strnlen(fc_host_symbolic_name(lport->host), + FC_SYMBOLIC_NAME_SIZE); ct = fc_ct_hdr_fill(fp, op, sizeof(struct fc_ns_rspn) + len, FC_FST_DIR, FC_NS_SUBTYPE); hton24(ct->payload.spn.fr_fid.fp_fid, lport->port_id); - strncpy(ct->payload.spn.fr_name, - fc_host_symbolic_name(lport->host), len); + memcpy(ct->payload.spn.fr_name, + fc_host_symbolic_name(lport->host), len); ct->payload.spn.fr_name_len = len; break; case FC_NS_RSNN_NN: - len = strnlen(fc_host_symbolic_name(lport->host), 255); + len = strnlen(fc_host_symbolic_name(lport->host), + FC_SYMBOLIC_NAME_SIZE); ct = fc_ct_hdr_fill(fp, op, sizeof(struct fc_ns_rsnn) + len, FC_FST_DIR, FC_NS_SUBTYPE); put_unaligned_be64(lport->wwnn, &ct->payload.snn.fr_wwn); - strncpy(ct->payload.snn.fr_name, - fc_host_symbolic_name(lport->host), len); + memcpy(ct->payload.snn.fr_name, + fc_host_symbolic_name(lport->host), len); ct->payload.snn.fr_name_len = len; break;