diff options
| author | Xin Long <lucien.xin@gmail.com> | 2021-05-17 02:28:58 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-03 09:00:37 +0200 |
| commit | 5195ec5e365a2a9331bfeb585b613a6e94f98dba (patch) | |
| tree | 914c504995ed766bf8936bc1388bb6aa5dfadf6f /net/tipc/core.c | |
| parent | 0aa2212940b85f71b81383e6bfdf70c439eeff04 (diff) | |
tipc: wait and exit until all work queues are done
commit 04c26faa51d1e2fe71cf13c45791f5174c37f986 upstream.
On some host, a crash could be triggered simply by repeating these
commands several times:
# modprobe tipc
# tipc bearer enable media udp name UDP1 localip 127.0.0.1
# rmmod tipc
[] BUG: unable to handle kernel paging request at ffffffffc096bb00
[] Workqueue: events 0xffffffffc096bb00
[] Call Trace:
[] ? process_one_work+0x1a7/0x360
[] ? worker_thread+0x30/0x390
[] ? create_worker+0x1a0/0x1a0
[] ? kthread+0x116/0x130
[] ? kthread_flush_work_fn+0x10/0x10
[] ? ret_from_fork+0x35/0x40
When removing the TIPC module, the UDP tunnel sock will be delayed to
release in a work queue as sock_release() can't be done in rtnl_lock().
If the work queue is schedule to run after the TIPC module is removed,
kernel will crash as the work queue function cleanup_beareri() code no
longer exists when trying to invoke it.
To fix it, this patch introduce a member wq_count in tipc_net to track
the numbers of work queues in schedule, and wait and exit until all
work queues are done in tipc_exit_net().
Fixes: d0f91938bede ("tipc: add ip/udp media type")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/tipc/core.c')
| -rw-r--r-- | net/tipc/core.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/tipc/core.c b/net/tipc/core.c index c2ff42900b53..40c03085c0ea 100644 --- a/net/tipc/core.c +++ b/net/tipc/core.c @@ -121,6 +121,8 @@ static void __net_exit tipc_exit_net(struct net *net) #ifdef CONFIG_TIPC_CRYPTO tipc_crypto_stop(&tipc_net(net)->crypto_tx); #endif + while (atomic_read(&tn->wq_count)) + cond_resched(); } static void __net_exit tipc_pernet_pre_exit(struct net *net) |