linux-stable.git/net/wireless/scan.c, branch linux-4.9.y

cfg80211: Fix possible memory leak in function cfg80211_bss_update

2021-08-04T09:58:03+00:00

commit f9a5c358c8d26fed0cc45f2afc64633d4ba21dff upstream.

When we exceed the limit of BSS entries, this function will free the
new entry, however, at this time, it is the last door to access the
inputed ies, so these ies will be unreferenced objects and cause memory
leak.
Therefore we should free its ies before deallocating the new entry, beside
of dropping it from hidden_list.

Signed-off-by: Nguyen Dinh Phi 
Link: https://lore.kernel.org/r/20210628132334.851095-1-phind.uet@gmail.com
Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

cfg80211: scan: drop entry from hidden_list on overflow

2021-05-22T08:40:21+00:00

commit 010bfbe768f7ecc876ffba92db30432de4997e2a upstream.

If we overflow the maximum number of BSS entries and free the
new entry, drop it from any hidden_list that it may have been
added to in the code above or in cfg80211_combine_bsses().

Reported-by: Dan Carpenter 
Link: https://lore.kernel.org/r/20210416094212.5de7d1676ad7.Ied283b0bc5f504845e7d6ab90626bdfa68bb3dc0@changeid
Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

cfg80211: add and use strongly typed element iteration macros

2019-10-17T20:42:21+00:00

commit 0f3b07f027f87a38ebe5c436490095df762819be upstream.

Rather than always iterating elements from frames with pure
u8 pointers, add a type "struct element" that encapsulates
the id/datalen/data format of them.

Then, add the element iteration macros
 * for_each_element
 * for_each_element_id
 * for_each_element_extid

which take, as their first 'argument', such a structure and
iterate through a given u8 array interpreting it as elements.

While at it and since we'll need it, also add
 * for_each_subelement
 * for_each_subelement_id
 * for_each_subelement_extid

which instead of taking data/length just take an outer element
and use its data/datalen.

Also add for_each_element_completed() to determine if any of
the loops above completed, i.e. it was able to parse all of
the elements successfully and no data remained.

Use for_each_element_id() in cfg80211_find_ie_match() as the
first user of this.

Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

cfg80211: Address some corner cases in scan result channel updating

2018-11-10T15:42:41+00:00

[ Upstream commit 119f94a6fefcc76d47075b83d2b73d04c895df78 ]

cfg80211_get_bss_channel() is used to update the RX channel based on the
available frame payload information (channel number from DSSS Parameter
Set element or HT Operation element). This is needed on 2.4 GHz channels
where frames may be received on neighboring channels due to overlapping
frequency range.

This might of some use on the 5 GHz band in some corner cases, but
things are more complex there since there is no n:1 or 1:n mapping
between channel numbers and frequencies due to multiple different
starting frequencies in different operating classes. This could result
in ieee80211_channel_to_frequency() returning incorrect frequency and
ieee80211_get_channel() returning incorrect channel information (or
indication of no match). In the previous implementation, this could
result in some scan results being dropped completely, e.g., for the 4.9
GHz channels. That prevented connection to such BSSs.

Fix this by using the driver-provided channel pointer if
ieee80211_get_channel() does not find matching channel data for the
channel number in the frame payload and if the scan is done with 5 MHz
or 10 MHz channel bandwidth. While doing this, also add comments
describing what the function is trying to achieve to make it easier to
understand what happens here and why.

Signed-off-by: Jouni Malinen 
Signed-off-by: Johannes Berg 
Signed-off-by: Sasha Levin

cfg80211: limit scan results cache size

2016-11-18T07:44:44+00:00

It's possible to make scanning consume almost arbitrary amounts
of memory, e.g. by sending beacon frames with random BSSIDs at
high rates while somebody is scanning.

Limit the number of BSS table entries we're willing to cache to
1000, limiting maximum memory usage to maybe 4-5MB, but lower
in practice - that would be the case for having both full-sized
beacon and probe response frames for each entry; this seems not
possible in practice, so a limit of 1000 entries will likely be
closer to 0.5 MB.

Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg

cfg80211: add helper to find an IE that matches a byte-array

2016-09-16T12:49:52+00:00

There are a few places where an IE that matches not only the EID, but
also other bytes inside the element, needs to be found.  To simplify
that and reduce the amount of similar code, implement a new helper
function to match the EID and an extra array of bytes.

Additionally, simplify cfg80211_find_vendor_ie() by using the new
match function.

Signed-off-by: Luca Coelho 
Signed-off-by: Johannes Berg

nl80211: support beacon report scanning

2016-07-06T12:51:31+00:00

Beacon report radio measurement requires reporting observed BSSs
on the channels specified in the beacon request. If the measurement
mode is set to passive or active, it requires actually performing a
scan (passive or active, accordingly), and reporting the time that
the scan was started and the time each beacon/probe was received
(both in terms of TSF of the BSS of the requesting AP). If the
request mode is table, this information is optional.
In addition, the radio measurement request specifies the channel
dwell time for the measurement.

In order to use scan for beacon report when the mode is active or
passive, add a parameter to scan request that specifies the
channel dwell time, and add scan start time and beacon received time
to scan results information.

Supporting beacon report is required for Multi Band Operation (MBO).

Signed-off-by: Assaf Krauss 
Signed-off-by: David Spinadel 
Signed-off-by: Avraham Stern 
Signed-off-by: Luca Coelho 
Signed-off-by: Johannes Berg

cfg80211: allow finding vendor with OUI without specifying the OUI type

2016-05-12T09:15:42+00:00

This allows finding vendor IE from a specific vendor.

Signed-off-by: Emmanuel Grumbach 
Signed-off-by: Luca Coelho 
Signed-off-by: Johannes Berg

cfg80211: remove enum ieee80211_band

2016-04-12T13:56:15+00:00

This enum is already perfectly aliased to enum nl80211_band, and
the only reason for it is that we get IEEE80211_NUM_BANDS out of
it. There's no really good reason to not declare the number of
bands in nl80211 though, so do that and remove the cfg80211 one.

Signed-off-by: Johannes Berg

cfg80211: Allow a scan request for a specific BSSID

2016-04-05T08:56:28+00:00

This allows scans for a specific BSSID to be optimized by the user space
application by requesting the driver to set the Probe Request frame
BSSID field (Address 3) to the specified BSSID instead of the wildcard
BSSID. This prevents other APs from replying which reduces airtime need
and latency in getting the response from the target AP through.

This is an optimization and as such, it is acceptable for some of the
drivers not to support the mechanism. If not supported, the wildcard
BSSID will be used and more responses may be received.

Signed-off-by: Jouni Malinen 
Signed-off-by: Johannes Berg