diff options
| author | Cong Wang <xiyou.wangcong@gmail.com> | 2020-05-01 21:11:08 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-05-04 21:59:20 +0300 |
| commit | 93a2014afbace907178afc3c9c1e62c9a338595a (patch) | |
| tree | 4d072dccbc4a89676c4c0b16a27162c9a4cdbe79 /net | |
| parent | 44d95cc6b10ff7439d45839c96c581cb4368c088 (diff) | |
| download | linux-93a2014afbace907178afc3c9c1e62c9a338595a.tar.xz | |
atm: fix a UAF in lec_arp_clear_vccs()
Gengming reported a UAF in lec_arp_clear_vccs(),
where we add a vcc socket to an entry in a per-device
list but free the socket without removing it from the
list when vcc->dev is NULL.
We need to call lec_vcc_close() to search and remove
those entries contain the vcc being destroyed. This can
be done by calling vcc->push(vcc, NULL) unconditionally
in vcc_destroy_socket().
Another issue discovered by Gengming's reproducer is
the vcc->dev may point to the static device lecatm_dev,
for which we don't need to register/unregister device,
so we can just check for vcc->dev->ops->owner.
Reported-by: Gengming Liu <l.dmxcsnsbh@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/atm/common.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/net/atm/common.c b/net/atm/common.c index 0ce530af534d..8575f5d52087 100644 --- a/net/atm/common.c +++ b/net/atm/common.c @@ -177,18 +177,18 @@ static void vcc_destroy_socket(struct sock *sk) set_bit(ATM_VF_CLOSE, &vcc->flags); clear_bit(ATM_VF_READY, &vcc->flags); - if (vcc->dev) { - if (vcc->dev->ops->close) - vcc->dev->ops->close(vcc); - if (vcc->push) - vcc->push(vcc, NULL); /* atmarpd has no push */ - module_put(vcc->owner); - - while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { - atm_return(vcc, skb->truesize); - kfree_skb(skb); - } + if (vcc->dev && vcc->dev->ops->close) + vcc->dev->ops->close(vcc); + if (vcc->push) + vcc->push(vcc, NULL); /* atmarpd has no push */ + module_put(vcc->owner); + + while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) { + atm_return(vcc, skb->truesize); + kfree_skb(skb); + } + if (vcc->dev && vcc->dev->ops->owner) { module_put(vcc->dev->ops->owner); atm_dev_put(vcc->dev); } |