cfg80211: check dev_set_name() return value

commit 59b179b48ce2a6076448a44531242ac2b3f6cef2 upstream.

syzbot reported a warning from rfkill_alloc(), and after a while
I think that the reason is that it was doing fault injection and
the dev_set_name() failed, leaving the name NULL, and we didn't
check the return value and got to rfkill_alloc() with a NULL name.
Since we really don't want a NULL name, we ought to check the
return value.

Fixes: fb28ad35906a ("net: struct device - replace bus_id with dev_name(), dev_set_name()")
Reported-by: syzbot+1ddfb3357e1d7bb5b5d3@syzkaller.appspotmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 59bc2ff8cfc59ed696eeaf45562f3f5b1d97f294..e2813667d5904848e7ba6860f8fe88cce8bb7076 100644 (file)
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -315,6 +315,7 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
 
        struct cfg80211_registered_device *rdev;
        int alloc_size;
+       int rv;
 
        WARN_ON(ops->add_key && (!ops->del_key || !ops->set_default_key));
        WARN_ON(ops->auth && (!ops->assoc || !ops->deauth || !ops->disassoc));
@@ -346,7 +347,11 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
        rdev->wiphy_idx--;
 
        /* give it a proper name */
-       dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
+       rv = dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
+       if (rv < 0) {
+               kfree(rdev);
+               return NULL;
+       }
 
        INIT_LIST_HEAD(&rdev->wdev_list);
        INIT_LIST_HEAD(&rdev->beacon_registrations);