cfg80211_ch_switch_notify uses ASSERT_WDEV_LOCK to assert that
net_device->ieee80211_ptr->mtx (which is the same as priv->wdev.mtx)
is held during the function's execution.
mwifiex_dfs_chan_sw_work_queue is one of its callers, which does not
hold that lock, therefore violating the assertion.
Add a lock around the call.
Disclaimer:
I am currently working on a static analyser to detect missing locks.
This was a reported case. I manually verified the report by looking
at the code, so that I do not send wrong information or patches.
After concluding that this seems to be a true positive, I created
this patch.
However, as I do not in fact have this particular hardware,
I was unable to test it.
Reviewed-by: Brian Norris <[email protected]>
Signed-off-by: Niels Dossche <[email protected]>
---
drivers/net/wireless/marvell/mwifiex/11h.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/wireless/marvell/mwifiex/11h.c b/drivers/net/wireless/marvell/mwifiex/11h.c
index d2ee6469e67b..3fa25cd64cda 100644
--- a/drivers/net/wireless/marvell/mwifiex/11h.c
+++ b/drivers/net/wireless/marvell/mwifiex/11h.c
@@ -303,5 +303,7 @@ void mwifiex_dfs_chan_sw_work_queue(struct work_struct *work)
mwifiex_dbg(priv->adapter, MSG,
"indicating channel switch completion to kernel\n");
+ mutex_lock(&priv->wdev.mtx);
cfg80211_ch_switch_notify(priv->netdev, &priv->dfs_chandef);
+ mutex_unlock(&priv->wdev.mtx);
}
--
2.35.1
Niels Dossche <[email protected]> wrote:
> cfg80211_ch_switch_notify uses ASSERT_WDEV_LOCK to assert that
> net_device->ieee80211_ptr->mtx (which is the same as priv->wdev.mtx)
> is held during the function's execution.
> mwifiex_dfs_chan_sw_work_queue is one of its callers, which does not
> hold that lock, therefore violating the assertion.
> Add a lock around the call.
>
> Disclaimer:
> I am currently working on a static analyser to detect missing locks.
> This was a reported case. I manually verified the report by looking
> at the code, so that I do not send wrong information or patches.
> After concluding that this seems to be a true positive, I created
> this patch.
> However, as I do not in fact have this particular hardware,
> I was unable to test it.
>
> Reviewed-by: Brian Norris <[email protected]>
> Signed-off-by: Niels Dossche <[email protected]>
Patch applied to wireless-next.git, thanks.
3e12968f6d12 mwifiex: add mutex lock for call in mwifiex_dfs_chan_sw_work_queue
--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches