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| author | Brian Norris <briannorris@chromium.org> | 2021-11-29 16:47:34 -0800 |
|---|---|---|
| committer | Kalle Valo <kvalo@kernel.org> | 2021-12-08 20:38:29 +0200 |
| commit | 1b8bb8919ef81bfc8873d223b9361f1685f2106d (patch) | |
| tree | 6eacdefdf8eaf6ec70e2e21ca883794b77ce8cf5 /drivers | |
| parent | f2f16ae9cc9cba4e3c70941cf6a6443c9ea920f4 (diff) | |
| download | linux-stable-1b8bb8919ef81bfc8873d223b9361f1685f2106d.tar.gz linux-stable-1b8bb8919ef81bfc8873d223b9361f1685f2106d.tar.bz2 linux-stable-1b8bb8919ef81bfc8873d223b9361f1685f2106d.zip | |
mwifiex: Fix possible ABBA deadlock
Quoting Jia-Ju Bai <baijiaju1990@gmail.com>:
mwifiex_dequeue_tx_packet()
spin_lock_bh(&priv->wmm.ra_list_spinlock); --> Line 1432 (Lock A)
mwifiex_send_addba()
spin_lock_bh(&priv->sta_list_spinlock); --> Line 608 (Lock B)
mwifiex_process_sta_tx_pause()
spin_lock_bh(&priv->sta_list_spinlock); --> Line 398 (Lock B)
mwifiex_update_ralist_tx_pause()
spin_lock_bh(&priv->wmm.ra_list_spinlock); --> Line 941 (Lock A)
Similar report for mwifiex_process_uap_tx_pause().
While the locking expectations in this driver are a bit unclear, the
Fixed commit only intended to protect the sta_ptr, so we can drop the
lock as soon as we're done with it.
IIUC, this deadlock cannot actually happen, because command event
processing (which calls mwifiex_process_sta_tx_pause()) is
sequentialized with TX packet processing (e.g.,
mwifiex_dequeue_tx_packet()) via the main loop (mwifiex_main_process()).
But it's good not to leave this potential issue lurking.
Fixes: f0f7c2275fb9 ("mwifiex: minor cleanups w/ sta_list_spinlock in cfg80211.c")
Cc: Douglas Anderson <dianders@chromium.org>
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Link: https://lore.kernel.org/linux-wireless/0e495b14-efbb-e0da-37bd-af6bd677ee2c@gmail.com/
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/YaV0pllJ5p/EuUat@google.com
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/wireless/marvell/mwifiex/sta_event.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/net/wireless/marvell/mwifiex/sta_event.c b/drivers/net/wireless/marvell/mwifiex/sta_event.c index 80e5d44bad9d..7d42c5d2dbf6 100644 --- a/drivers/net/wireless/marvell/mwifiex/sta_event.c +++ b/drivers/net/wireless/marvell/mwifiex/sta_event.c @@ -365,10 +365,12 @@ static void mwifiex_process_uap_tx_pause(struct mwifiex_private *priv, sta_ptr = mwifiex_get_sta_entry(priv, tp->peermac); if (sta_ptr && sta_ptr->tx_pause != tp->tx_pause) { sta_ptr->tx_pause = tp->tx_pause; + spin_unlock_bh(&priv->sta_list_spinlock); mwifiex_update_ralist_tx_pause(priv, tp->peermac, tp->tx_pause); + } else { + spin_unlock_bh(&priv->sta_list_spinlock); } - spin_unlock_bh(&priv->sta_list_spinlock); } } @@ -400,11 +402,13 @@ static void mwifiex_process_sta_tx_pause(struct mwifiex_private *priv, sta_ptr = mwifiex_get_sta_entry(priv, tp->peermac); if (sta_ptr && sta_ptr->tx_pause != tp->tx_pause) { sta_ptr->tx_pause = tp->tx_pause; + spin_unlock_bh(&priv->sta_list_spinlock); mwifiex_update_ralist_tx_pause(priv, tp->peermac, tp->tx_pause); + } else { + spin_unlock_bh(&priv->sta_list_spinlock); } - spin_unlock_bh(&priv->sta_list_spinlock); } } } |