diff options
| author | Dmitry Antipov <dmantipov@yandex.ru> | 2024-09-06 15:31:51 +0300 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2024-09-09 11:45:06 +0200 |
| commit | 9d301de12da6e1bb069a9835c38359b8e8135121 (patch) | |
| tree | 30ccad67944fb99dc55840126ec7f088cceaf5c0 /net/mac80211/iface.c | |
| parent | 15ea13b1b1fbf6364d4cd568e65e4c8479632999 (diff) | |
wifi: mac80211: use two-phase skb reclamation in ieee80211_do_stop()
Since '__dev_queue_xmit()' should be called with interrupts enabled,
the following backtrace:
ieee80211_do_stop()
...
spin_lock_irqsave(&local->queue_stop_reason_lock, flags)
...
ieee80211_free_txskb()
ieee80211_report_used_skb()
ieee80211_report_ack_skb()
cfg80211_mgmt_tx_status_ext()
nl80211_frame_tx_status()
genlmsg_multicast_netns()
genlmsg_multicast_netns_filtered()
nlmsg_multicast_filtered()
netlink_broadcast_filtered()
do_one_broadcast()
netlink_broadcast_deliver()
__netlink_sendskb()
netlink_deliver_tap()
__netlink_deliver_tap_skb()
dev_queue_xmit()
__dev_queue_xmit() ; with IRQS disabled
...
spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags)
issues the warning (as reported by syzbot reproducer):
WARNING: CPU: 2 PID: 5128 at kernel/softirq.c:362 __local_bh_enable_ip+0xc3/0x120
Fix this by implementing a two-phase skb reclamation in
'ieee80211_do_stop()', where actual work is performed
outside of a section with interrupts disabled.
Fixes: 5061b0c2b906 ("mac80211: cooperate more with network namespaces")
Reported-by: syzbot+1a3986bbd3169c307819@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1a3986bbd3169c307819
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Link: https://patch.msgid.link/20240906123151.351647-1-dmantipov@yandex.ru
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211/iface.c')
| -rw-r--r-- | net/mac80211/iface.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index e074de893ed6..6ef0990d3d29 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -462,6 +462,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, bool going_do { struct ieee80211_local *local = sdata->local; unsigned long flags; + struct sk_buff_head freeq; struct sk_buff *skb, *tmp; u32 hw_reconf_flags = 0; int i, flushed; @@ -637,18 +638,32 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, bool going_do skb_queue_purge(&sdata->status_queue); } + /* + * Since ieee80211_free_txskb() may issue __dev_queue_xmit() + * which should be called with interrupts enabled, reclamation + * is done in two phases: + */ + __skb_queue_head_init(&freeq); + + /* unlink from local queues... */ spin_lock_irqsave(&local->queue_stop_reason_lock, flags); for (i = 0; i < IEEE80211_MAX_QUEUES; i++) { skb_queue_walk_safe(&local->pending[i], skb, tmp) { struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); if (info->control.vif == &sdata->vif) { __skb_unlink(skb, &local->pending[i]); - ieee80211_free_txskb(&local->hw, skb); + __skb_queue_tail(&freeq, skb); } } } spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); + /* ... and perform actual reclamation with interrupts enabled. */ + skb_queue_walk_safe(&freeq, skb, tmp) { + __skb_unlink(skb, &freeq); + ieee80211_free_txskb(&local->hw, skb); + } + if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) ieee80211_txq_remove_vlan(local, sdata); |