DPDK patches and discussions
 help / color / mirror / Atom feed
From: Thomas Monjalon <thomas@monjalon.net>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: dev@dpdk.org, ferruh.yigit@intel.com
Subject: Re: [dpdk-dev] [RFC 2/5] bus/pci: fix TOCTOU issue
Date: Sun, 18 Nov 2018 16:04:38 +0100	[thread overview]
Message-ID: <45370656.e11tQEUeGQ@xps> (raw)
In-Reply-To: <20181106214901.1392-3-stephen@networkplumber.org>

+Cc Ferruh

06/11/2018 22:48, Stephen Hemminger:
> Using access followed by open causes a static analysis warning
> about Time of check versus Time of use. Also, access() and
> open() have different UID permission checks.
> 
> This is not a serious problem; but easy to fix by using errno instead.
> 
> Coverity issue: 300870
> Fixes: 4a928ef9f611 ("bus/pci: enable write combining during mapping")
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> ---
>  drivers/bus/pci/linux/pci_uio.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/bus/pci/linux/pci_uio.c b/drivers/bus/pci/linux/pci_uio.c
> index 112ac51dddcc..8521fe63b0ae 100644
> --- a/drivers/bus/pci/linux/pci_uio.c
> +++ b/drivers/bus/pci/linux/pci_uio.c
> @@ -306,12 +306,11 @@ pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
>  			loc->domain, loc->bus, loc->devid,
>  			loc->function, res_idx);
>  
> -		if (access(devname, R_OK|W_OK) != -1) {
> -			fd = open(devname, O_RDWR);
> -			if (fd < 0)
> -				RTE_LOG(INFO, EAL, "%s cannot be mapped. "
> -					"Fall-back to non prefetchable mode.\n",
> -					devname);
> +		fd = open(devname, O_RDWR);
> +		if (fd < 0 && errno != ENOENT) {
> +			RTE_LOG(INFO, EAL, "%s cannot be mapped. "
> +				"Fall-back to non prefetchable mode.\n",
> +				devname);
>  		}
>  	}

  reply	other threads:[~2018-11-18 15:04 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-06 21:48 [dpdk-dev] [RFC 0/5] more Coverity related bug fixes Stephen Hemminger
2018-11-06 21:48 ` [dpdk-dev] [RFC 1/5] bus/pci: fix allocation of pci device path Stephen Hemminger
2018-11-18 15:03   ` Thomas Monjalon
2018-11-22 23:52   ` Ferruh Yigit
2018-11-23  0:29   ` [dpdk-dev] [PATCH] bus/pci: fix allocation of PCI " Ferruh Yigit
2018-11-23 10:45     ` Thomas Monjalon
2018-11-23 10:55       ` Andrew Rybchenko
2018-11-23 11:01     ` Maxime Coquelin
2018-11-25 10:53       ` Thomas Monjalon
2018-11-06 21:48 ` [dpdk-dev] [RFC 2/5] bus/pci: fix TOCTOU issue Stephen Hemminger
2018-11-18 15:04   ` Thomas Monjalon [this message]
2018-11-06 21:48 ` [dpdk-dev] [RFC 3/5] bpf: fix validation of eal_divmod Stephen Hemminger
2018-11-07 12:54   ` Ananyev, Konstantin
2018-11-07 19:51     ` Stephen Hemminger
2018-11-07 20:07       ` Ananyev, Konstantin
2018-11-07 23:04       ` Ananyev, Konstantin
2018-11-06 21:49 ` [dpdk-dev] [RFC 4/5] eal/memory: avoid double munmap in error path Stephen Hemminger
2018-11-06 23:10   ` Thomas Monjalon
2018-11-06 21:49 ` [dpdk-dev] [RFC 5/5] pipeline: remove dead code Stephen Hemminger
2018-11-18 15:07   ` Thomas Monjalon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=45370656.e11tQEUeGQ@xps \
    --to=thomas@monjalon.net \
    --cc=dev@dpdk.org \
    --cc=ferruh.yigit@intel.com \
    --cc=stephen@networkplumber.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).