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staging: rtl8192u: Replace GFP_ATOMIC with GFP_KERNEL in ieee80211_tkip_init

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ieee80211_tkip_init() is never called in atomic context.

ieee80211_tkip_init() is only set as ".init" in
struct ieee80211_crypto_ops.
The call chains ending up at "->init" function are:
[1] ->init() <- ieee80211_wpa_set_encryption() <-
    ieee80211_wpa_supplicant_ioctl()
[2] ->init() <- ieee80211_wx_set_encode_ext_rsl() <-
    r8192_wx_set_enc_ext()
[3] ->init() <- ieee80211_wx_set_encode_rsl() <-
    r8192_wx_set_enc()

ieee80211_wpa_supplicant_ioctl(), r8192_wx_set_enc_ext() and
r8192_wx_set_enc() call mutex_lock(), which indicates these functions
are not called in atomic context.

Despite never getting called from atomic context,
ieee80211_tkip_init() calls kzalloc() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jia-Ju Bai
2018-04-10 20:23:29 +08:00
committed by Greg Kroah-Hartman
parent 98743f8749
commit 2accd50e15
1 changed files with 1 additions and 1 deletions
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2
drivers/staging/rtl8192u/ieee80211/ieee80211_crypt_tkip.c
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@@ -66,7 +66,7 @@ static void *ieee80211_tkip_init(int key_idx)
{
struct ieee80211_tkip_data *priv;
priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
goto fail;
priv->key_idx = key_idx;