diff options
| author | Jakub Kicinski <[email protected]> | 2022-06-29 11:19:10 -0700 |
|---|---|---|
| committer | Jakub Kicinski <[email protected]> | 2022-06-30 11:34:10 -0700 |
| commit | ff1fa2081d173b01cebe2fbf0a2d0f1cee9ce4b5 (patch) | |
| tree | 257bdc6083b6cb0de9b9fb20c4cea6dc724fb60a | |
| parent | 9c5de246c1dbe785268fc2e83c88624b92e4ec93 (diff) | |
net: tun: avoid disabling NAPI twice
Eric reports that syzbot made short work out of my speculative
fix. Indeed when queue gets detached its tfile->tun remains,
so we would try to stop NAPI twice with a detach(), close()
sequence.
Alternative fix would be to move tun_napi_disable() to
tun_detach_all() and let the NAPI run after the queue
has been detached.
Fixes: a8fc8cb5692a ("net: tun: stop NAPI when detaching queues")
Reported-by: syzbot <[email protected]>
Reported-by: Eric Dumazet <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
| -rw-r--r-- | drivers/net/tun.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e2eb35887394..259b2b84b2b3 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -640,7 +640,8 @@ static void __tun_detach(struct tun_file *tfile, bool clean) tun = rtnl_dereference(tfile->tun); if (tun && clean) { - tun_napi_disable(tfile); + if (!tfile->detached) + tun_napi_disable(tfile); tun_napi_del(tfile); } |