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Commit 8b6d5c1e authored by Miaoqing Pan's avatar Miaoqing Pan Committed by Greg Kroah-Hartman
Browse files

mac80211: fix txq null pointer dereference 



[ Upstream commit 8ed31a264065ae92058ce54aa3cc8da8d81dc6d7 ]

If the interface type is P2P_DEVICE or NAN, read the file of
'/sys/kernel/debug/ieee80211/phyx/netdev:wlanx/aqm' will get a
NULL pointer dereference. As for those interface type, the
pointer sdata->vif.txq is NULL.

Unable to handle kernel NULL pointer dereference at virtual address 00000011
CPU: 1 PID: 30936 Comm: cat Not tainted 4.14.104 #1
task: ffffffc0337e4880 task.stack: ffffff800cd20000
PC is at ieee80211_if_fmt_aqm+0x34/0xa0 [mac80211]
LR is at ieee80211_if_fmt_aqm+0x34/0xa0 [mac80211]
[...]
Process cat (pid: 30936, stack limit = 0xffffff800cd20000)
[...]
[<ffffff8000b7cd00>] ieee80211_if_fmt_aqm+0x34/0xa0 [mac80211]
[<ffffff8000b7c414>] ieee80211_if_read+0x60/0xbc [mac80211]
[<ffffff8000b7ccc4>] ieee80211_if_read_aqm+0x28/0x30 [mac80211]
[<ffffff80082eff94>] full_proxy_read+0x2c/0x48
[<ffffff80081eef00>] __vfs_read+0x2c/0xd4
[<ffffff80081ef084>] vfs_read+0x8c/0x108
[<ffffff80081ef494>] SyS_read+0x40/0x7c

Signed-off-by: default avatarMiaoqing Pan <miaoqing@codeaurora.org>
Acked-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/1569549796-8223-1-git-send-email-miaoqing@codeaurora.org


[trim useless data from commit message]
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 2f153000

net/mac80211/debugfs_netdev.c

+9 −2
Original line number Diff line number Diff line
@@ -490,9 +490,14 @@ static ssize_t ieee80211_if_fmt_aqm( 
	const struct ieee80211_sub_if_data *sdata, char *buf, int buflen)

{

	struct ieee80211_local *local = sdata->local;

	struct txq_info *txqi = to_txq_info(sdata->vif.txq);

	struct txq_info *txqi;

	int len;



	if (!sdata->vif.txq)

		return 0;



	txqi = to_txq_info(sdata->vif.txq);



	spin_lock_bh(&local->fq.lock);

	rcu_read_lock();
@@ -657,7 +662,9 @@ static void add_common_files(struct ieee80211_sub_if_data *sdata) 
	DEBUGFS_ADD(rc_rateidx_vht_mcs_mask_5ghz);

	DEBUGFS_ADD(hw_queues);



	if (sdata->local->ops->wake_tx_queue)

	if (sdata->local->ops->wake_tx_queue &&

	    sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&

	    sdata->vif.type != NL80211_IFTYPE_NAN)

		DEBUGFS_ADD(aqm);

}