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authorJason Wang <jasowang@redhat.com>2018-05-16 20:39:33 +0800
committerDavid S. Miller <davem@davemloft.net>2018-05-16 14:53:10 -0400
commit7063efd33bb15abc0160347f89eb5aba6b7d000e (patch)
treeb60645544d7381dd2337323566ed402620d0e163 /drivers/net/tun.c
parentfee8fb952d1e1c1a60e2017878a16cf83c92c154 (diff)
downloadlinux-7063efd33bb15abc0160347f89eb5aba6b7d000e.tar.bz2
tuntap: fix use after free during release
After commit b196d88aba8a ("tun: fix use after free for ptr_ring") we need clean up tx ring during release(). But unfortunately, it tries to do the cleanup blindly after socket were destroyed which will lead another use-after-free. Fix this by doing the cleanup before dropping the last reference of the socket in __tun_detach(). Reported-by: Andrei Vagin <avagin@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Fixes: b196d88aba8a ("tun: fix use after free for ptr_ring") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 9fbbb328b95b..d45ac37e1287 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -729,6 +729,7 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
}
if (tun)
xdp_rxq_info_unreg(&tfile->xdp_rxq);
+ ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
sock_put(&tfile->sk);
}
}
@@ -3245,7 +3246,6 @@ static int tun_chr_close(struct inode *inode, struct file *file)
struct tun_file *tfile = file->private_data;
tun_detach(tfile, true);
- ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
return 0;
}