A previous commit 4f68ef64cd ("cw1200: Fix concurrency
use-after-free bugs in cw1200_hw_scan()") tried to fix a seemingly
use-after-free bug between cw1200_bss_info_changed() and
cw1200_hw_scan(), where the former frees a sk_buff pointed
to by frame.skb, and the latter accesses the sk_buff
pointed to by frame.skb. However, this issue should be a
false alarm because:
(1) "frame.skb" is not a shared variable between the above
two functions, because "frame" is a local function variable,
each of the two functions has its own local "frame" - they
just happen to have the same variable name.
(2) the sk_buff(s) pointed to by these two "frame.skb" are
also two different object instances, they are individually
allocated by different dev_alloc_skb() within the two above
functions. To free one object instance will not invalidate
the access of another different one.
Based on these facts, the previous commit should be unnecessary.
Moreover, it also introduced a missing unlock which was
addressed in a subsequent commit 51c8d24101 ("cw1200: fix missing
unlock on error in cw1200_hw_scan()"). Now that the
original use-after-free is unreal, these two commits should
be reverted. This patch performs the reversion.
Fixes: 4f68ef64cd ("cw1200: Fix concurrency use-after-free bugs in cw1200_hw_scan()")
Fixes: 51c8d24101 ("cw1200: fix missing unlock on error in cw1200_hw_scan()")
Signed-off-by: Hang Zhang <zh.nvgt@gmail.com>
Acked-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210521223238.25020-1-zh.nvgt@gmail.com
The dev_kfree_skb() function performs also input parameter validation.
Thus the test around the shown calls is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the missing unlock before return from function cw1200_hw_scan()
in the error handling case.
Fixes: 4f68ef64cd ("cw1200: Fix concurrency use-after-free bugs in cw1200_hw_scan()")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
The function cw1200_bss_info_changed() and cw1200_hw_scan() can be
concurrently executed.
The two functions both access a possible shared variable "frame.skb".
This shared variable is freed by dev_kfree_skb() in cw1200_upload_beacon(),
which is called by cw1200_bss_info_changed(). The free operation is
protected by a mutex lock "priv->conf_mutex" in cw1200_bss_info_changed().
In cw1200_hw_scan(), this shared variable is accessed without the
protection of the mutex lock "priv->conf_mutex".
Thus, concurrency use-after-free bugs may occur.
To fix these bugs, the original calls to mutex_lock(&priv->conf_mutex) and
mutex_unlock(&priv->conf_mutex) are moved to the places, which can
protect the accesses to the shared variable.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.
An spatch similar to the one for skb_put_zero() converts many
of the places using it:
@@
identifier p, p2;
expression len, skb, data;
type t, t2;
@@
(
-p = skb_put(skb, len);
+p = skb_put_data(skb, data, len);
|
-p = (t)skb_put(skb, len);
+p = skb_put_data(skb, data, len);
)
(
p2 = (t2)p;
-memcpy(p2, data, len);
|
-memcpy(p, data, len);
)
@@
type t, t2;
identifier p, p2;
expression skb, data;
@@
t *p;
...
(
-p = skb_put(skb, sizeof(t));
+p = skb_put_data(skb, data, sizeof(t));
|
-p = (t *)skb_put(skb, sizeof(t));
+p = skb_put_data(skb, data, sizeof(t));
)
(
p2 = (t2)p;
-memcpy(p2, data, sizeof(*p));
|
-memcpy(p, data, sizeof(*p));
)
@@
expression skb, len, data;
@@
-memcpy(skb_put(skb, len), data, len);
+skb_put_data(skb, data, len);
(again, manually post-processed to retain some comments)
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the following to support beacon report radio measurement
with the measurement mode field set to passive or active:
1. Propagate the required scan duration to the device
2. Report the scan start time (in terms of TSF)
3. Report each BSS's detection time (also in terms of TSF)
TSF times refer to the BSS that the interface that requested the
scan is connected to.
Signed-off-by: Assaf Krauss <assaf.krauss@intel.com>
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
[changed ath9k/10k, at76c59x-usb, iwlegacy, wl1251 and wlcore to match
the new API]
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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 <johannes.berg@intel.com>
