[Patch net v3] tun: fix a memory leak for tfile->tx_array
From: Cong Wang <hidden>
Date: 2018-01-15 19:37:35
Subsystem:
networking drivers, the rest, tun/tap driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn, Jason Wang
tfile->tun could be detached before we close the tun fd,
via tun_detach_all(), so it should not be used to check for
tfile->tx_array.
As Jason suggested, we probably have to clean it up
unconditionally both in __tun_deatch() and tun_detach_all(),
but this requires to check if it is initialized or not.
Currently skb_array_cleanup() doesn't have such a check,
so I check it in the caller and introduce a helper function,
it is a bit ugly but we can always improve it in net-next.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: 1576d9860599 ("tun: switch to use skb array for tx")
Cc: Jason Wang <redacted>
Signed-off-by: Cong Wang <redacted>
---
drivers/net/tun.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 4f4a842a1c9c..a8ec589d1359 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c@@ -611,6 +611,14 @@ static void tun_queue_purge(struct tun_file *tfile) skb_queue_purge(&tfile->sk.sk_error_queue); } +static void tun_cleanup_tx_array(struct tun_file *tfile) +{ + if (tfile->tx_array.ring.queue) { + skb_array_cleanup(&tfile->tx_array); + memset(&tfile->tx_array, 0, sizeof(tfile->tx_array)); + } +} + static void __tun_detach(struct tun_file *tfile, bool clean) { struct tun_file *ntfile;
@@ -657,8 +665,7 @@ static void __tun_detach(struct tun_file *tfile, bool clean) tun->dev->reg_state == NETREG_REGISTERED) unregister_netdevice(tun->dev); } - if (tun) - skb_array_cleanup(&tfile->tx_array); + tun_cleanup_tx_array(tfile); sock_put(&tfile->sk); } }
@@ -700,11 +707,13 @@ static void tun_detach_all(struct net_device *dev) /* Drop read queue */ tun_queue_purge(tfile); sock_put(&tfile->sk); + tun_cleanup_tx_array(tfile); } list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) { tun_enable_queue(tfile); tun_queue_purge(tfile); sock_put(&tfile->sk); + tun_cleanup_tx_array(tfile); } BUG_ON(tun->numdisabled != 0);
@@ -2851,6 +2860,8 @@ static int tun_chr_open(struct inode *inode, struct file * file) sock_set_flag(&tfile->sk, SOCK_ZEROCOPY); + memset(&tfile->tx_array, 0, sizeof(tfile->tx_array)); + return 0; }
--
2.13.0