From: Johannes Berg johannes.berg@intel.com
commit 7bc40aedf24d31d8bea80e1161e996ef4299fb10 upstream.
If sta_info_insert_finish() fails, we currently keep the station around and free it only in the caller, but there's only one such caller and it always frees it immediately.
As syzbot found, another consequence of this split is that we can put things that sleep only into __cleanup_single_sta() and not in sta_info_free(), but this is the only place that requires such of sta_info_free() now.
Change this to free the station in sta_info_insert_finish(), in which case we can still sleep. This will also let us unify the cleanup code later.
Cc: stable@vger.kernel.org Fixes: dcd479e10a05 ("mac80211: always wind down STA state") Reported-by: syzbot+32c6c38c4812d22f2f0b@syzkaller.appspotmail.com Reported-by: syzbot+4c81fe92e372d26c4246@syzkaller.appspotmail.com Reported-by: syzbot+6a7fe9faf0d1d61bc24a@syzkaller.appspotmail.com Reported-by: syzbot+abed06851c5ffe010921@syzkaller.appspotmail.com Reported-by: syzbot+b7aeb9318541a1c709f1@syzkaller.appspotmail.com Reported-by: syzbot+d5a9416c6cafe53b5dd0@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20201112112201.ee6b397b9453.I9c31d667a0ea2151441cc... Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/mac80211/sta_info.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-)
--- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -705,7 +705,7 @@ static int sta_info_insert_finish(struct out_drop_sta: local->num_sta--; synchronize_net(); - __cleanup_single_sta(sta); + cleanup_single_sta(sta); out_err: mutex_unlock(&local->sta_mtx); kfree(sinfo); @@ -724,19 +724,13 @@ int sta_info_insert_rcu(struct sta_info
err = sta_info_insert_check(sta); if (err) { + sta_info_free(local, sta); mutex_unlock(&local->sta_mtx); rcu_read_lock(); - goto out_free; + return err; }
- err = sta_info_insert_finish(sta); - if (err) - goto out_free; - - return 0; - out_free: - sta_info_free(local, sta); - return err; + return sta_info_insert_finish(sta); }
int sta_info_insert(struct sta_info *sta)