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| author |   Jakub Kicinski <kuba@kernel.org> | 2022-06-29 11:19:10 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-06-30 11:34:10 -0700 |
| commit | ff1fa2081d173b01cebe2fbf0a2d0f1cee9ce4b5 (patch) | |
| tree | 257bdc6083b6cb0de9b9fb20c4cea6dc724fb60a /drivers | |
| parent | net: sparx5: mdb add/del handle non-sparx5 devices (diff) | |
| download | wireguard-linux-ff1fa2081d173b01cebe2fbf0a2d0f1cee9ce4b5.tar.xz wireguard-linux-ff1fa2081d173b01cebe2fbf0a2d0f1cee9ce4b5.zip | |
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 <syzkaller@googlegroups.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220629181911.372047-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -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); } |