wifi: nl80211: re-check wiphy netns in testmode and vendor dump continuations

Commit 79240f3f6d76 ("wifi: nl80211: re-check wiphy netns in
nl80211_prepare_wdev_dump() continuation") fixed one dumpit path that
looked the wiphy up by index on a later call without confirming it was
still in the caller's netns. Two more dumpit paths have the same gap.

nl80211_testmode_dump() and nl80211_prepare_vendor_dump() both keep the
wiphy index in cb->args[] and look it up again on later calls, through
cfg80211_rdev_by_wiphy_idx() and wiphy_idx_to_wiphy(). The first call
binds to the caller's netns. A later call does not check it again. In
between, the wiphy can move to another netns via
NL80211_CMD_SET_WIPHY_NETNS.

Add the same net_eq() check to both. On a mismatch, return -ENODEV and
the dump ends.

No mainline driver registers .testmode_dump or
wiphy_vendor_command.dumpit, so these paths are not reachable today.
Drivers outside the tree can register either.

Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Link: https://patch.msgid.link/20260527133358.2853238-1-maoyixie.tju@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c272a2fbad03fa2247a666595af311b894dccf3f..cdb5e9b77143d7a0e9a7631632040b6750699137 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -13730,6 +13730,16 @@ static int nl80211_testmode_dump(struct sk_buff *skb,
                        err = -ENOENT;
                        goto out_err;
                }
+
+               /*
+                * The wiphy may have moved netns between dumpit
+                * invocations (via NL80211_CMD_SET_WIPHY_NETNS), so
+                * re-check that it still matches the caller's netns.
+                */
+               if (!net_eq(wiphy_net(&rdev->wiphy), sock_net(skb->sk))) {
+                       err = -ENODEV;
+                       goto out_err;
+               }
        } else {
                attrbuf = kzalloc_objs(*attrbuf, NUM_NL80211_ATTR);
                if (!attrbuf) {
@@ -17771,6 +17781,15 @@ static int nl80211_prepare_vendor_dump(struct sk_buff *skb,
 
                if (!wiphy)
                        return -ENODEV;
+
+               /*
+                * The wiphy may have moved netns between dumpit
+                * invocations (via NL80211_CMD_SET_WIPHY_NETNS), so
+                * re-check that it still matches the caller's netns.
+                */
+               if (!net_eq(wiphy_net(wiphy), sock_net(skb->sk)))
+                       return -ENODEV;
+
                *rdev = wiphy_to_rdev(wiphy);
                *wdev = NULL;