From: Luca Coelho <luca@coelho.fi>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Laura Abbott <labbott@redhat.com>,
linux-kernel@vger.kernel.org,
Johannes Berg <johannes.berg@intel.com>,
Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
Intel Linux Wireless <linuxwifi@intel.com>,
Kalle Valo <kvalo@codeaurora.org>,
linux-wireless@vger.kernel.org, stable <stable@vger.kernel.org>
Subject: Re: [PATCH] iwlwifi: properly check debugfs dentry before using it
Date: Wed, 17 Apr 2019 10:02:54 +0300 [thread overview]
Message-ID: <05f0923dce988a9c4cfb870013c49ca4136afbdb.camel@coelho.fi> (raw)
In-Reply-To: <20190330093152.GB14300@kroah.com>
On Sat, 2019-03-30 at 10:31 +0100, Greg Kroah-Hartman wrote:
> debugfs can now report an error code if something went wrong instead
> of
> just NULL. So if the return value is to be used as a "real" dentry,
> it
> needs to be checked if it is an error before dereferencing it.
>
> This is now happening because of ff9fb72bc077 ("debugfs: return error
> values, not NULL"). If multiple iwlwifi devices are in the system,
> this
> can cause problems when the driver attempts to create the main
> debugfs
> directory again. Later on in the code we fail horribly by trying to
> dereference a pointer that is an error value.
>
> Reported-by: Laura Abbott <labbott@redhat.com>
> Cc: Johannes Berg <johannes.berg@intel.com>
> Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
> Cc: Luca Coelho <luciano.coelho@intel.com>
> Cc: Intel Linux Wireless <linuxwifi@intel.com>
> Cc: Kalle Valo <kvalo@codeaurora.org>
> Cc: stable <stable@vger.kernel.org> # 5.0
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
> b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
> index 2453ceabf00d..6925527d8457 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
> @@ -774,8 +774,7 @@ void iwl_mvm_vif_dbgfs_register(struct iwl_mvm
> *mvm, struct ieee80211_vif *vif)
> return;
>
> mvmvif->dbgfs_dir = debugfs_create_dir("iwlmvm", dbgfs_dir);
> -
> - if (!mvmvif->dbgfs_dir) {
> + if (IS_ERR_OR_NULL(mvmvif->dbgfs_dir)) {
> IWL_ERR(mvm, "Failed to create debugfs directory under
> %pd\n",
> dbgfs_dir);
> return;
Thanks! I've applied this internally and will send upstream for v5.1-
rc* following our normal upstreaming process.
I added the other Reported-by that Laura asked for and added "mvm:" to
the subject.
--
Cheers,
Luca.
prev parent reply other threads:[~2019-04-17 7:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-22 15:21 [PATCH] iwlwifi: mvm: no need to check return value of debugfs_create functions Greg Kroah-Hartman
2019-01-25 19:30 ` Luciano Coelho
2019-03-26 23:55 ` Laura Abbott
2019-03-27 1:26 ` Greg Kroah-Hartman
2019-03-27 1:47 ` Laura Abbott
2019-03-27 1:53 ` Greg Kroah-Hartman
2019-03-27 6:35 ` Luca Coelho
2019-03-30 9:22 ` Greg Kroah-Hartman
2019-03-30 9:31 ` [PATCH] iwlwifi: properly check debugfs dentry before using it Greg Kroah-Hartman
2019-04-01 15:39 ` Laura Abbott
2019-04-17 7:02 ` Luca Coelho [this message]
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=05f0923dce988a9c4cfb870013c49ca4136afbdb.camel@coelho.fi \
--to=luca@coelho.fi \
--cc=emmanuel.grumbach@intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=johannes.berg@intel.com \
--cc=kvalo@codeaurora.org \
--cc=labbott@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=linuxwifi@intel.com \
--cc=stable@vger.kernel.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).