wifi: cfg80211: convert pmsr_free_wk to wiphy_work to fix deadlock

When a netlink socket that owns a PMSR session is closed,
cfg80211_release_pmsr() clears the request's nl_portid and queues
pmsr_free_wk to call cfg80211_pmsr_process_abort() asynchronously.

If the interface tears down concurrently, cfg80211_pmsr_wdev_down()
is called under wiphy_lock and calls cancel_work_sync(&pmsr_free_wk)
to wait for any running work. The work function acquires wiphy_lock
via guard(wiphy) before calling process_abort.

This is a deadlock: wdev_down holds wiphy_lock and blocks inside
cancel_work_sync(); pmsr_free_wk blocks trying to acquire that same
wiphy_lock. Neither thread can proceed.

The same deadlock is reachable from cfg80211_leave_locked(), which
calls cfg80211_pmsr_wdev_down() for all interface types under
wiphy_lock.

Fix this by converting pmsr_free_wk from a plain work_struct to a
wiphy_work. The wiphy_work dispatcher holds wiphy_lock when running
work items, so the explicit guard(wiphy) in the work function is no
longer needed. wiphy_work_cancel() can be called safely while holding
wiphy_lock - since wiphy_lock prevents the work from running
concurrently, wiphy_work_cancel() never blocks, eliminating the
deadlock.

Remove the cancel_work_sync() for pmsr_free_wk from the
NETDEV_GOING_DOWN handler. cfg80211_leave(), called unconditionally
just before it, already cancels any pending work under wiphy_lock
via wiphy_work_cancel() inside cfg80211_pmsr_wdev_down().

Fixes: 6dccbc9f3e1d ("wifi: cfg80211: cancel pmsr_free_wk in cfg80211_pmsr_wdev_down")
Signed-off-by: Peddolla Harshavardhan Reddy <peddolla.reddy@oss.qualcomm.com>
Link: https://patch.msgid.link/20260703082523.2629324-1-peddolla.reddy@oss.qualcomm.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 8188ad200de5..3751a1d74765 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -7265,7 +7265,7 @@ struct wireless_dev {
 
 	struct list_head pmsr_list;
 	spinlock_t pmsr_lock;
-	struct work_struct pmsr_free_wk;
+	struct wiphy_work pmsr_free_wk;
 
 	unsigned long unprot_beacon_reported;