2021-02-25 06:05:53

by Brian Norris

Subject: [PATCH] mwifiex: don't print SSID to logs

There are a few reasons not to dump SSIDs as-is in kernel logs:

1) they're not guaranteed to be any particular text encoding (UTF-8,
ASCII, ...) in general
2) it's somewhat redundant; the BSSID should be enough to uniquely
identify the AP/STA to which we're connecting
3) BSSIDs have an easily-recognized format, whereas SSIDs do not (they
are free-form)
4) other common drivers (e.g., everything based on mac80211) get along
just fine by only including BSSIDs when logging state transitions

Additional notes on reason #3: this is important for the
privacy-conscious, especially when providing tools that convey
kernel logs on behalf of a user -- e.g., when reporting bugs. So for
example, it's easy to automatically filter logs for MAC addresses, but
it's much harder to filter SSIDs out of unstructured text.

Signed-off-by: Brian Norris <[email protected]>
---
drivers/net/wireless/marvell/mwifiex/cfg80211.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
index a2ed268ce0da..0961f4a5e415 100644
--- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
@@ -2300,8 +2300,7 @@ mwifiex_cfg80211_assoc(struct mwifiex_private *priv, size_t ssid_len,
is_scanning_required = 1;
} else {
mwifiex_dbg(priv->adapter, MSG,
- "info: trying to associate to '%.*s' bssid %pM\n",
- req_ssid.ssid_len, (char *)req_ssid.ssid,
+ "info: trying to associate to bssid %pM\n",
bss->bssid);
memcpy(&priv->cfg_bssid, bss->bssid, ETH_ALEN);
break;
@@ -2378,8 +2377,7 @@ mwifiex_cfg80211_connect(struct wiphy *wiphy, struct net_device *dev,
}

mwifiex_dbg(adapter, INFO,
- "info: Trying to associate to %.*s and bssid %pM\n",
- (int)sme->ssid_len, (char *)sme->ssid, sme->bssid);
+ "info: Trying to associate to bssid %pM\n", sme->bssid);

if (!mwifiex_stop_bg_scan(priv))
cfg80211_sched_scan_stopped_locked(priv->wdev.wiphy, 0);
@@ -2512,9 +2510,8 @@ mwifiex_cfg80211_join_ibss(struct wiphy *wiphy, struct net_device *dev,
goto done;
}

- mwifiex_dbg(priv->adapter, MSG,
- "info: trying to join to %.*s and bssid %pM\n",
- params->ssid_len, (char *)params->ssid, params->bssid);
+ mwifiex_dbg(priv->adapter, MSG, "info: trying to join to bssid %pM\n",
+ params->bssid);

mwifiex_set_ibss_params(priv, params);

--
2.30.0.617.g56c4b15f3c-goog

2021-04-17 17:47:57

by Kalle Valo

Subject: Re: [PATCH] mwifiex: don't print SSID to logs

Brian Norris <[email protected]> wrote:

> There are a few reasons not to dump SSIDs as-is in kernel logs:
>
> 1) they're not guaranteed to be any particular text encoding (UTF-8,
> ASCII, ...) in general
> 2) it's somewhat redundant; the BSSID should be enough to uniquely
> identify the AP/STA to which we're connecting
> 3) BSSIDs have an easily-recognized format, whereas SSIDs do not (they
> are free-form)
> 4) other common drivers (e.g., everything based on mac80211) get along
> just fine by only including BSSIDs when logging state transitions
>
> Additional notes on reason #3: this is important for the
> privacy-conscious, especially when providing tools that convey
> kernel logs on behalf of a user -- e.g., when reporting bugs. So for
> example, it's easy to automatically filter logs for MAC addresses, but
> it's much harder to filter SSIDs out of unstructured text.
>
> Signed-off-by: Brian Norris <[email protected]>

Patch applied to wireless-drivers-next.git, thanks.

d23a96220353 mwifiex: don't print SSID to logs

--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches