From patchwork Thu Oct 26 23:13:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Stitt X-Patchwork-Id: 13438000 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 7C1092EAE1 for ; Thu, 26 Oct 2023 23:13:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bN4zFCBY" Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFDCB1B8 for ; Thu, 26 Oct 2023 16:13:43 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-da0ccfc4fc8so418616276.2 for ; Thu, 26 Oct 2023 16:13:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1698362023; x=1698966823; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=HFiYbHBnckwihvKNnIEzm/rfvH9bcBh1GF02ZnqdljM=; b=bN4zFCBY2JVStE89J87k/8Jm1cMxIQfefsBJ2xunT7VToOgjuBzdx73ZAraKPT+5z6 TKJM1KmHKnajoOgoq5vajdS7vSqgVkf6GldMKRnEAw20OY3ehqBY6SbBi3HvH4iD4FtX MyAacJfkCKC99gAJ4PZ/tI55WUTx5r9e7vh9yC3tzYGkQLmIlYG10A6+aSp2T/8irdhT BB1lgMKQGFbU6SQckwaXNT81ClFlogDsvLEpeiz6naIY5onKQZPhFXsKZ9UacR7is1vZ icRC+g3zVYnVsotB+rpSWJ4Qwz9Em8sa7WfS+vXe75ZEo50uGENyT7/8+nnxe8dP2P3F p6mQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698362023; x=1698966823; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=HFiYbHBnckwihvKNnIEzm/rfvH9bcBh1GF02ZnqdljM=; b=SxI8mFqWS3k35rMOI9NMml0W/qQ8raCdRL1TcsU6G0BNI6WlOvX4G/YhSEbMC0WIoc hMwi2/Q5twebILtGVPYa08uqsOWzcYzyrnhwpKy51fgDo1pxO9Bk+S1jblKpVu8SEF1y BZF5a72cUOB/8XMVKgulEU4MquxEcgZWbXicv5px5stY4qWMmwpCwDdy/aZW/ONRnyRl 5AM+IXinfTOtV1z3xrokkJuWe6PLAvooNoDQGb11Ejvd/TAZIYVypohEBEaQnQmRzYDF isIl8HF/IsBytr9IH8tXfmxAkP0S9ZaY/k+G0WxvVN+7rEHS8GuRDhaEezC+MMBMI0Kg riGg== X-Gm-Message-State: AOJu0YxYWAUEnSIBOwebTmeOTdDD7pwbl70VFmXNizd0PWTqHoRWqanQ YMBp7NZrr87FAXMouC0lssZhhnSvU57Wfd/m0Q== X-Google-Smtp-Source: AGHT+IEbj/4BJ8b1hPqD/NX25gwqtVhAmHTTpu9NZP2j6GhL2fKwNIRSfM1OPid7YKbd48tyWmUJ9qcmHeD3xmsLjw== X-Received: from jstitt-linux1.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:23b5]) (user=justinstitt job=sendgmr) by 2002:a25:5509:0:b0:da0:5e08:5c71 with SMTP id j9-20020a255509000000b00da05e085c71mr18091ybb.5.1698362023143; Thu, 26 Oct 2023 16:13:43 -0700 (PDT) Date: Thu, 26 Oct 2023 23:13:41 +0000 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAKTyOmUC/43NQQ6CMBCF4auQrh1DK9jginsYFrQdYBKlZIY0E sLdrZzA5fcW/9uVIBOKehS7YkwkFOcMcymUn/p5RKCQrUxpbro0d5CVZ79sEJgSsoB4IZgW6cF D5Z11ocLG2UHlwsI40OesP7vsiWSNvJ1nSf/W/7pJgwZb17oJtteNdu0Y4/jCq49v1R3H8QWR1 dYsxwAAAA== X-Developer-Key: i=justinstitt@google.com; a=ed25519; pk=tC3hNkJQTpNX/gLKxTNQKDmiQl6QjBNCGKJINqAdJsE= X-Developer-Signature: v=1; a=ed25519-sha256; t=1698362022; l=5530; i=justinstitt@google.com; s=20230717; h=from:subject:message-id; bh=vKXzL31/mEChO1m4jkNSZ9EryWsuWIfXEfMiSRto9RY=; b=O7JSLUVSbnMyjX4uJV6/3PWg9N26ln+o7xUz1QBQ0rsWPyyaDVCnMLpxqNtKs+loM0rh85JmI 8o0Q1uLmrjWA9dTB+40R6NqrT19NPe2bOO62sl4f+BLOoIbCnMfBZz3 X-Mailer: b4 0.12.3 Message-ID: <20231026-strncpy-drivers-scsi-hpsa-c-v2-1-2fe2d05122fd@google.com> Subject: [PATCH v2] scsi: hpsa: replace deprecated strncpy From: Justin Stitt To: Don Brace , "James E.J. Bottomley" , "Martin K. Petersen" Cc: storagedev@microchip.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Kees Cook , Justin Stitt strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. Instances of strncpy()'ing a string into a buffer and manually NUL-terminating followed by sccanf with just "%d" as the format specifier can be accomplished by strscpy() and kstrtoint(). strscpy() guarantees NUL-termination on the destination buffer and kstrtoint is better way of getting strings turned into ints. For the last two strncpy() use cases in init_driver_version(), we can actually drop this function entirely. Firstly, we are kmalloc()'ing driver_version. Then, we are calling init_driver_version() which memset's it to 0 followed by a strncpy(). The pattern is 1) allocating memory for a string, 2) setting all bytes to NUL, 3) copy bytes from another string + ensure NUL-padded. For these, we can just stack allocate driver_version and old_driver_version. This simplifies the code greatly as we don't have any malloc/free or strncpy's. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Cc: Kees Cook Signed-off-by: Justin Stitt --- Changes in v2: - use stack for buffers (thanks Kees) - use kstrtoint (thanks Kees) - Link to v1: https://lore.kernel.org/r/20231026-strncpy-drivers-scsi-hpsa-c-v1-1-75519d7a191b@google.com --- Note: build-tested only. Found with: $ rg "strncpy\(" --- drivers/scsi/hpsa.c | 53 ++++++++++++++++++++--------------------------------- 1 file changed, 20 insertions(+), 33 deletions(-) --- base-commit: d88520ad73b79e71e3ddf08de335b8520ae41c5c change-id: 20231026-strncpy-drivers-scsi-hpsa-c-4cb7bd4e9b7f Best regards, -- Justin Stitt diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index af18d20f3079..4d42fbb071cf 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -452,18 +452,18 @@ static ssize_t host_store_hp_ssd_smart_path_status(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int status, len; + int status; struct ctlr_info *h; struct Scsi_Host *shost = class_to_shost(dev); char tmpbuf[10]; if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) return -EACCES; - len = count > sizeof(tmpbuf) - 1 ? sizeof(tmpbuf) - 1 : count; - strncpy(tmpbuf, buf, len); - tmpbuf[len] = '\0'; - if (sscanf(tmpbuf, "%d", &status) != 1) + + strscpy(tmpbuf, buf, sizeof(tmpbuf)); + if (kstrtoint(tmpbuf, 0, &status)) return -EINVAL; + h = shost_to_hba(shost); h->acciopath_status = !!status; dev_warn(&h->pdev->dev, @@ -476,18 +476,18 @@ static ssize_t host_store_raid_offload_debug(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int debug_level, len; + int debug_level; struct ctlr_info *h; struct Scsi_Host *shost = class_to_shost(dev); char tmpbuf[10]; if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) return -EACCES; - len = count > sizeof(tmpbuf) - 1 ? sizeof(tmpbuf) - 1 : count; - strncpy(tmpbuf, buf, len); - tmpbuf[len] = '\0'; - if (sscanf(tmpbuf, "%d", &debug_level) != 1) + + strscpy(tmpbuf, buf, sizeof(tmpbuf)); + if (kstrtoint(tmpbuf, 0, &debug_level)) return -EINVAL; + if (debug_level < 0) debug_level = 0; h = shost_to_hba(shost); @@ -7234,25 +7234,15 @@ static int hpsa_controller_hard_reset(struct pci_dev *pdev, return 0; } -static void init_driver_version(char *driver_version, int len) -{ - memset(driver_version, 0, len); - strncpy(driver_version, HPSA " " HPSA_DRIVER_VERSION, len - 1); -} - static int write_driver_ver_to_cfgtable(struct CfgTable __iomem *cfgtable) { - char *driver_version; int i, size = sizeof(cfgtable->driver_version); + char driver_version[sizeof(cfgtable->driver_version)] = + HPSA " " HPSA_DRIVER_VERSION; - driver_version = kmalloc(size, GFP_KERNEL); - if (!driver_version) - return -ENOMEM; - - init_driver_version(driver_version, size); for (i = 0; i < size; i++) writeb(driver_version[i], &cfgtable->driver_version[i]); - kfree(driver_version); + return 0; } @@ -7268,21 +7258,18 @@ static void read_driver_ver_from_cfgtable(struct CfgTable __iomem *cfgtable, static int controller_reset_failed(struct CfgTable __iomem *cfgtable) { - char *driver_ver, *old_driver_ver; - int rc, size = sizeof(cfgtable->driver_version); - - old_driver_ver = kmalloc_array(2, size, GFP_KERNEL); - if (!old_driver_ver) - return -ENOMEM; - driver_ver = old_driver_ver + size; + char driver_ver[sizeof(cfgtable->driver_version)] = ""; + char old_driver_ver[sizeof(cfgtable->driver_version)] = + HPSA " " HPSA_DRIVER_VERSION; + int rc; /* After a reset, the 32 bytes of "driver version" in the cfgtable * should have been changed, otherwise we know the reset failed. */ - init_driver_version(old_driver_ver, size); read_driver_ver_from_cfgtable(cfgtable, driver_ver); - rc = !memcmp(driver_ver, old_driver_ver, size); - kfree(old_driver_ver); + rc = !memcmp(driver_ver, old_driver_ver, + sizeof(cfgtable->driver_version)); + return rc; } /* This does a hard reset of the controller using PCI power management