This is a note to let you know that I've just added the patch titled
mac80211: free sta in sta_info_insert_finish() on errors
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mac80211-free-sta-in-sta_info_insert_finish-on-errors.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7bc40aedf24d31d8bea80e1161e996ef4299fb10 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@xxxxxxxxx>
Date: Thu, 12 Nov 2020 11:22:04 +0100
Subject: mac80211: free sta in sta_info_insert_finish() on errors
From: Johannes Berg <johannes.berg@xxxxxxxxx>
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@xxxxxxxxxxxxxxx
Fixes: dcd479e10a05 ("mac80211: always wind down STA state")
Reported-by: syzbot+32c6c38c4812d22f2f0b@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+4c81fe92e372d26c4246@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+6a7fe9faf0d1d61bc24a@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+abed06851c5ffe010921@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+b7aeb9318541a1c709f1@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+d5a9416c6cafe53b5dd0@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20201112112201.ee6b397b9453.I9c31d667a0ea2151441cc64ed6613d36c18a48e0@changeid
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -583,7 +583,7 @@ 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);
@@ -602,19 +602,13 @@ 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)
Patches currently in stable-queue which might be from johannes.berg@xxxxxxxxx are
queue-4.4/mac80211-minstrel-fix-tx-status-processing-corner-case.patch
queue-4.4/mac80211-allow-driver-to-prevent-two-stations-w-same-address.patch
queue-4.4/mac80211-minstrel-remove-deferred-sampling-code.patch
queue-4.4/mac80211-free-sta-in-sta_info_insert_finish-on-errors.patch
