* [PATCH AUTOSEL 4.4 1/3] ax25: NPD bug when detaching AX25 device
@ 2021-12-27 19:06 Sasha Levin
2021-12-27 19:06 ` [PATCH AUTOSEL 4.4 2/3] phonet/pep: refuse to enable an unbound pipe Sasha Levin
0 siblings, 1 reply; 2+ messages in thread
From: Sasha Levin @ 2021-12-27 19:06 UTC (permalink / raw
To: linux-kernel, stable
Cc: Lin Ma, Hanjie Wu, David S . Miller, Sasha Levin, jreuter, kuba,
linux-hams, netdev
From: Lin Ma <linma@zju.edu.cn>
[ Upstream commit 1ade48d0c27d5da1ccf4b583d8c5fc8b534a3ac8 ]
The existing cleanup routine implementation is not well synchronized
with the syscall routine. When a device is detaching, below race could
occur.
static int ax25_sendmsg(...) {
...
lock_sock()
ax25 = sk_to_ax25(sk);
if (ax25->ax25_dev == NULL) // CHECK
...
ax25_queue_xmit(skb, ax25->ax25_dev->dev); // USE
...
}
static void ax25_kill_by_device(...) {
...
if (s->ax25_dev == ax25_dev) {
s->ax25_dev = NULL;
...
}
Other syscall functions like ax25_getsockopt, ax25_getname,
ax25_info_show also suffer from similar races. To fix them, this patch
introduce lock_sock() into ax25_kill_by_device in order to guarantee
that the nullify action in cleanup routine cannot proceed when another
socket request is pending.
Signed-off-by: Hanjie Wu <nagi@zju.edu.cn>
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ax25/af_ax25.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index 64fede18aa33f..f4c8567e91b38 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -88,8 +88,10 @@ static void ax25_kill_by_device(struct net_device *dev)
again:
ax25_for_each(s, &ax25_list) {
if (s->ax25_dev == ax25_dev) {
- s->ax25_dev = NULL;
spin_unlock_bh(&ax25_list_lock);
+ lock_sock(s->sk);
+ s->ax25_dev = NULL;
+ release_sock(s->sk);
ax25_disconnect(s, ENETUNREACH);
spin_lock_bh(&ax25_list_lock);
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH AUTOSEL 4.4 2/3] phonet/pep: refuse to enable an unbound pipe
2021-12-27 19:06 [PATCH AUTOSEL 4.4 1/3] ax25: NPD bug when detaching AX25 device Sasha Levin
@ 2021-12-27 19:06 ` Sasha Levin
0 siblings, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2021-12-27 19:06 UTC (permalink / raw
To: linux-kernel, stable
Cc: Rémi Denis-Courmont, syzbot+2dc91e7fc3dea88b1e8a,
David S . Miller, Sasha Levin, courmisch, kuba, netdev
From: Rémi Denis-Courmont <remi@remlab.net>
[ Upstream commit 75a2f31520095600f650597c0ac41f48b5ba0068 ]
This ioctl() implicitly assumed that the socket was already bound to
a valid local socket name, i.e. Phonet object. If the socket was not
bound, two separate problems would occur:
1) We'd send an pipe enablement request with an invalid source object.
2) Later socket calls could BUG on the socket unexpectedly being
connected yet not bound to a valid object.
Reported-by: syzbot+2dc91e7fc3dea88b1e8a@syzkaller.appspotmail.com
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/phonet/pep.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/phonet/pep.c b/net/phonet/pep.c
index f6aa532bcbf64..1e7945df39928 100644
--- a/net/phonet/pep.c
+++ b/net/phonet/pep.c
@@ -956,6 +956,8 @@ static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
ret = -EBUSY;
else if (sk->sk_state == TCP_ESTABLISHED)
ret = -EISCONN;
+ else if (!pn->pn_sk.sobject)
+ ret = -EADDRNOTAVAIL;
else
ret = pep_sock_enable(sk, NULL, 0);
release_sock(sk);
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
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