This is a note to let you know that I've just added the patch titled
ppp: fix race in ppp device destruction
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
ppp-fix-race-in-ppp-device-destruction.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Guillaume Nault <g.nault(a)alphalink.fr>
Date: Fri, 6 Oct 2017 17:05:49 +0200
Subject: ppp: fix race in ppp device destruction
From: Guillaume Nault <g.nault(a)alphalink.fr>
[ Upstream commit 6151b8b37b119e8e3a8401b080d532520c95faf4 ]
ppp_release() tries to ensure that netdevices are unregistered before
decrementing the unit refcount and running ppp_destroy_interface().
This is all fine as long as the the device is unregistered by
ppp_release(): the unregister_netdevice() call, followed by
rtnl_unlock(), guarantee that the unregistration process completes
before rtnl_unlock() returns.
However, the device may be unregistered by other means (like
ppp_nl_dellink()). If this happens right before ppp_release() calling
rtnl_lock(), then ppp_release() has to wait for the concurrent
unregistration code to release the lock.
But rtnl_unlock() releases the lock before completing the device
unregistration process. This allows ppp_release() to proceed and
eventually call ppp_destroy_interface() before the unregistration
process completes. Calling free_netdev() on this partially unregistered
device will BUG():
------------[ cut here ]------------
kernel BUG at net/core/dev.c:8141!
invalid opcode: 0000 [#1] SMP
CPU: 1 PID: 1557 Comm: pppd Not tainted 4.14.0-rc2+ #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014
Call Trace:
ppp_destroy_interface+0xd8/0xe0 [ppp_generic]
ppp_disconnect_channel+0xda/0x110 [ppp_generic]
ppp_unregister_channel+0x5e/0x110 [ppp_generic]
pppox_unbind_sock+0x23/0x30 [pppox]
pppoe_connect+0x130/0x440 [pppoe]
SYSC_connect+0x98/0x110
? do_fcntl+0x2c0/0x5d0
SyS_connect+0xe/0x10
entry_SYSCALL_64_fastpath+0x1a/0xa5
RIP: free_netdev+0x107/0x110 RSP: ffffc28a40573d88
---[ end trace ed294ff0cc40eeff ]---
We could set the ->needs_free_netdev flag on PPP devices and move the
ppp_destroy_interface() logic in the ->priv_destructor() callback. But
that'd be quite intrusive as we'd first need to unlink from the other
channels and units that depend on the device (the ones that used the
PPPIOCCONNECT and PPPIOCATTACH ioctls).
Instead, we can just let the netdevice hold a reference on its
ppp_file. This reference is dropped in ->priv_destructor(), at the very
end of the unregistration process, so that neither ppp_release() nor
ppp_disconnect_channel() can call ppp_destroy_interface() in the interim.
Reported-by: Beniamino Galvani <bgalvani(a)redhat.com>
Fixes: 8cb775bc0a34 ("ppp: fix device unregistration upon netns deletion")
Signed-off-by: Guillaume Nault <g.nault(a)alphalink.fr>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/net/ppp/ppp_generic.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -1338,7 +1338,17 @@ ppp_get_stats64(struct net_device *dev,
static int ppp_dev_init(struct net_device *dev)
{
+ struct ppp *ppp;
+
netdev_lockdep_set_classes(dev);
+
+ ppp = netdev_priv(dev);
+ /* Let the netdevice take a reference on the ppp file. This ensures
+ * that ppp_destroy_interface() won't run before the device gets
+ * unregistered.
+ */
+ atomic_inc(&ppp->file.refcnt);
+
return 0;
}
@@ -1361,6 +1371,15 @@ static void ppp_dev_uninit(struct net_de
wake_up_interruptible(&ppp->file.rwait);
}
+static void ppp_dev_priv_destructor(struct net_device *dev)
+{
+ struct ppp *ppp;
+
+ ppp = netdev_priv(dev);
+ if (atomic_dec_and_test(&ppp->file.refcnt))
+ ppp_destroy_interface(ppp);
+}
+
static const struct net_device_ops ppp_netdev_ops = {
.ndo_init = ppp_dev_init,
.ndo_uninit = ppp_dev_uninit,
@@ -1386,6 +1405,7 @@ static void ppp_setup(struct net_device
dev->tx_queue_len = 3;
dev->type = ARPHRD_PPP;
dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+ dev->destructor = ppp_dev_priv_destructor;
netif_keep_dst(dev);
}
Patches currently in stable-queue which might be from g.nault(a)alphalink.fr are
queue-4.9/ppp-fix-race-in-ppp-device-destruction.patch
queue-4.9/l2tp-check-ps-sock-before-running-pppol2tp_session_ioctl.patch
This is a note to let you know that I've just added the patch titled
packet: avoid panic in packet_getsockopt()
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
packet-avoid-panic-in-packet_getsockopt.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Eric Dumazet <edumazet(a)google.com>
Date: Wed, 18 Oct 2017 16:14:52 -0700
Subject: packet: avoid panic in packet_getsockopt()
From: Eric Dumazet <edumazet(a)google.com>
[ Upstream commit 509c7a1ecc8601f94ffba8a00889fefb239c00c6 ]
syzkaller got crashes in packet_getsockopt() processing
PACKET_ROLLOVER_STATS command while another thread was managing
to change po->rollover
Using RCU will fix this bug. We might later add proper RCU annotations
for sparse sake.
In v2: I replaced kfree(rollover) in fanout_add() to kfree_rcu()
variant, as spotted by John.
Fixes: a9b6391814d5 ("packet: rollover statistics")
Signed-off-by: Eric Dumazet <edumazet(a)google.com>
Cc: Willem de Bruijn <willemb(a)google.com>
Cc: John Sperbeck <jsperbeck(a)google.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
net/packet/af_packet.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1720,7 +1720,7 @@ static int fanout_add(struct sock *sk, u
out:
if (err && rollover) {
- kfree(rollover);
+ kfree_rcu(rollover, rcu);
po->rollover = NULL;
}
mutex_unlock(&fanout_mutex);
@@ -1747,8 +1747,10 @@ static struct packet_fanout *fanout_rele
else
f = NULL;
- if (po->rollover)
+ if (po->rollover) {
kfree_rcu(po->rollover, rcu);
+ po->rollover = NULL;
+ }
}
mutex_unlock(&fanout_mutex);
@@ -3851,6 +3853,7 @@ static int packet_getsockopt(struct sock
void *data = &val;
union tpacket_stats_u st;
struct tpacket_rollover_stats rstats;
+ struct packet_rollover *rollover;
if (level != SOL_PACKET)
return -ENOPROTOOPT;
@@ -3929,13 +3932,18 @@ static int packet_getsockopt(struct sock
0);
break;
case PACKET_ROLLOVER_STATS:
- if (!po->rollover)
+ rcu_read_lock();
+ rollover = rcu_dereference(po->rollover);
+ if (rollover) {
+ rstats.tp_all = atomic_long_read(&rollover->num);
+ rstats.tp_huge = atomic_long_read(&rollover->num_huge);
+ rstats.tp_failed = atomic_long_read(&rollover->num_failed);
+ data = &rstats;
+ lv = sizeof(rstats);
+ }
+ rcu_read_unlock();
+ if (!rollover)
return -EINVAL;
- rstats.tp_all = atomic_long_read(&po->rollover->num);
- rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
- rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
- data = &rstats;
- lv = sizeof(rstats);
break;
case PACKET_TX_HAS_OFF:
val = po->tp_tx_has_off;
Patches currently in stable-queue which might be from edumazet(a)google.com are
queue-4.9/net-call-cgroup_sk_alloc-earlier-in-sk_clone_lock.patch
queue-4.9/tcp-dccp-fix-ireq-opt-races.patch
queue-4.9/tcp-fix-tcp_mtu_probe-vs-highest_sack.patch
queue-4.9/ipv6-addrconf-increment-ifp-refcount-before-ipv6_del_addr.patch
queue-4.9/ipv6-flowlabel-do-not-leave-opt-tot_len-with-garbage.patch
queue-4.9/packet-avoid-panic-in-packet_getsockopt.patch
queue-4.9/sctp-add-the-missing-sock_owned_by_user-check-in-sctp_icmp_redirect.patch
queue-4.9/net_sched-avoid-matching-qdisc-with-zero-handle.patch
queue-4.9/tun-tap-sanitize-tunsetsndbuf-input.patch
queue-4.9/tcp-dccp-fix-lockdep-splat-in-inet_csk_route_req.patch
queue-4.9/tcp-dccp-fix-other-lockdep-splats-accessing-ireq_opt.patch
This is a note to let you know that I've just added the patch titled
netlink: do not set cb_running if dump's start() errs
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
netlink-do-not-set-cb_running-if-dump-s-start-errs.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: "Jason A. Donenfeld" <Jason(a)zx2c4.com>
Date: Mon, 9 Oct 2017 14:14:51 +0200
Subject: netlink: do not set cb_running if dump's start() errs
From: "Jason A. Donenfeld" <Jason(a)zx2c4.com>
[ Upstream commit 41c87425a1ac9b633e0fcc78eb1f19640c8fb5a0 ]
It turns out that multiple places can call netlink_dump(), which means
it's still possible to dereference partially initialized values in
dump() that were the result of a faulty returned start().
This fixes the issue by calling start() _before_ setting cb_running to
true, so that there's no chance at all of hitting the dump() function
through any indirect paths.
It also moves the call to start() to be when the mutex is held. This has
the nice side effect of serializing invocations to start(), which is
likely desirable anyway. It also prevents any possible other races that
might come out of this logic.
In testing this with several different pieces of tricky code to trigger
these issues, this commit fixes all avenues that I'm aware of.
Signed-off-by: Jason A. Donenfeld <Jason(a)zx2c4.com>
Cc: Johannes Berg <johannes(a)sipsolutions.net>
Reviewed-by: Johannes Berg <johannes(a)sipsolutions.net>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
net/netlink/af_netlink.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2207,16 +2207,17 @@ int __netlink_dump_start(struct sock *ss
cb->min_dump_alloc = control->min_dump_alloc;
cb->skb = skb;
+ if (cb->start) {
+ ret = cb->start(cb);
+ if (ret)
+ goto error_unlock;
+ }
+
nlk->cb_running = true;
mutex_unlock(nlk->cb_mutex);
- ret = 0;
- if (cb->start)
- ret = cb->start(cb);
-
- if (!ret)
- ret = netlink_dump(sk);
+ ret = netlink_dump(sk);
sock_put(sk);
Patches currently in stable-queue which might be from Jason(a)zx2c4.com are
queue-4.9/netlink-do-not-set-cb_running-if-dump-s-start-errs.patch
This is a note to let you know that I've just added the patch titled
net_sched: avoid matching qdisc with zero handle
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
net_sched-avoid-matching-qdisc-with-zero-handle.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Cong Wang <xiyou.wangcong(a)gmail.com>
Date: Fri, 27 Oct 2017 22:08:56 -0700
Subject: net_sched: avoid matching qdisc with zero handle
From: Cong Wang <xiyou.wangcong(a)gmail.com>
[ Upstream commit 50317fce2cc70a2bbbc4b42c31bbad510382a53c ]
Davide found the following script triggers a NULL pointer
dereference:
ip l a name eth0 type dummy
tc q a dev eth0 parent :1 handle 1: htb
This is because for a freshly created netdevice noop_qdisc
is attached and when passing 'parent :1', kernel actually
tries to match the major handle which is 0 and noop_qdisc
has handle 0 so is matched by mistake. Commit 69012ae425d7
tries to fix a similar bug but still misses this case.
Handle 0 is not a valid one, should be just skipped. In
fact, kernel uses it as TC_H_UNSPEC.
Fixes: 69012ae425d7 ("net: sched: fix handling of singleton qdiscs with qdisc_hash")
Fixes: 59cc1f61f09c ("net: sched:convert qdisc linked list to hashtable")
Reported-by: Davide Caratti <dcaratti(a)redhat.com>
Cc: Jiri Kosina <jkosina(a)suse.cz>
Cc: Eric Dumazet <edumazet(a)google.com>
Cc: Jamal Hadi Salim <jhs(a)mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong(a)gmail.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
net/sched/sch_api.c | 2 ++
1 file changed, 2 insertions(+)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -296,6 +296,8 @@ struct Qdisc *qdisc_lookup(struct net_de
{
struct Qdisc *q;
+ if (!handle)
+ return NULL;
q = qdisc_match_from_root(dev->qdisc, handle);
if (q)
goto out;
Patches currently in stable-queue which might be from xiyou.wangcong(a)gmail.com are
queue-4.9/tun-call-dev_get_valid_name-before-register_netdevice.patch
queue-4.9/net_sched-avoid-matching-qdisc-with-zero-handle.patch
queue-4.9/tun-allow-positive-return-values-on-dev_get_valid_name-call.patch
This is a note to let you know that I've just added the patch titled
net/unix: don't show information about sockets from other namespaces
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
net-unix-don-t-show-information-about-sockets-from-other-namespaces.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Andrei Vagin <avagin(a)openvz.org>
Date: Wed, 25 Oct 2017 10:16:42 -0700
Subject: net/unix: don't show information about sockets from other namespaces
From: Andrei Vagin <avagin(a)openvz.org>
[ Upstream commit 0f5da659d8f1810f44de14acf2c80cd6499623a0 ]
socket_diag shows information only about sockets from a namespace where
a diag socket lives.
But if we request information about one unix socket, the kernel don't
check that its netns is matched with a diag socket namespace, so any
user can get information about any unix socket in a system. This looks
like a bug.
v2: add a Fixes tag
Fixes: 51d7cccf0723 ("net: make sock diag per-namespace")
Signed-off-by: Andrei Vagin <avagin(a)openvz.org>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
net/unix/diag.c | 2 ++
1 file changed, 2 insertions(+)
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -257,6 +257,8 @@ static int unix_diag_get_exact(struct sk
err = -ENOENT;
if (sk == NULL)
goto out_nosk;
+ if (!net_eq(sock_net(sk), net))
+ goto out;
err = sock_diag_check_cookie(sk, req->udiag_cookie);
if (err)
Patches currently in stable-queue which might be from avagin(a)openvz.org are
queue-4.9/net-unix-don-t-show-information-about-sockets-from-other-namespaces.patch
This is a note to let you know that I've just added the patch titled
net: call cgroup_sk_alloc() earlier in sk_clone_lock()
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
net-call-cgroup_sk_alloc-earlier-in-sk_clone_lock.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Eric Dumazet <edumazet(a)google.com>
Date: Tue, 10 Oct 2017 19:12:33 -0700
Subject: net: call cgroup_sk_alloc() earlier in sk_clone_lock()
From: Eric Dumazet <edumazet(a)google.com>
[ Upstream commit c0576e3975084d4699b7bfef578613fb8e1144f6 ]
If for some reason, the newly allocated child need to be freed,
we will call cgroup_put() (via sk_free_unlock_clone()) while the
corresponding cgroup_get() was not yet done, and we will free memory
too soon.
Fixes: d979a39d7242 ("cgroup: duplicate cgroup reference when cloning sockets")
Signed-off-by: Eric Dumazet <edumazet(a)google.com>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: Tejun Heo <tj(a)kernel.org>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
net/core/sock.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1526,6 +1526,7 @@ struct sock *sk_clone_lock(const struct
newsk->sk_userlocks = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
sock_reset_flag(newsk, SOCK_DONE);
+ cgroup_sk_alloc(&newsk->sk_cgrp_data);
skb_queue_head_init(&newsk->sk_error_queue);
filter = rcu_dereference_protected(newsk->sk_filter, 1);
@@ -1560,8 +1561,6 @@ struct sock *sk_clone_lock(const struct
atomic64_set(&newsk->sk_cookie, 0);
mem_cgroup_sk_alloc(newsk);
- cgroup_sk_alloc(&newsk->sk_cgrp_data);
-
/*
* Before updating sk_refcnt, we must commit prior changes to memory
* (Documentation/RCU/rculist_nulls.txt for details)
Patches currently in stable-queue which might be from edumazet(a)google.com are
queue-4.9/net-call-cgroup_sk_alloc-earlier-in-sk_clone_lock.patch
queue-4.9/tcp-dccp-fix-ireq-opt-races.patch
queue-4.9/tcp-fix-tcp_mtu_probe-vs-highest_sack.patch
queue-4.9/ipv6-addrconf-increment-ifp-refcount-before-ipv6_del_addr.patch
queue-4.9/ipv6-flowlabel-do-not-leave-opt-tot_len-with-garbage.patch
queue-4.9/packet-avoid-panic-in-packet_getsockopt.patch
queue-4.9/sctp-add-the-missing-sock_owned_by_user-check-in-sctp_icmp_redirect.patch
queue-4.9/net_sched-avoid-matching-qdisc-with-zero-handle.patch
queue-4.9/tun-tap-sanitize-tunsetsndbuf-input.patch
queue-4.9/tcp-dccp-fix-lockdep-splat-in-inet_csk_route_req.patch
queue-4.9/tcp-dccp-fix-other-lockdep-splats-accessing-ireq_opt.patch
This is a note to let you know that I've just added the patch titled
l2tp: check ps->sock before running pppol2tp_session_ioctl()
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
l2tp-check-ps-sock-before-running-pppol2tp_session_ioctl.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Guillaume Nault <g.nault(a)alphalink.fr>
Date: Fri, 13 Oct 2017 19:22:35 +0200
Subject: l2tp: check ps->sock before running pppol2tp_session_ioctl()
From: Guillaume Nault <g.nault(a)alphalink.fr>
[ Upstream commit 5903f594935a3841137c86b9d5b75143a5b7121c ]
When pppol2tp_session_ioctl() is called by pppol2tp_tunnel_ioctl(),
the session may be unconnected. That is, it was created by
pppol2tp_session_create() and hasn't been connected with
pppol2tp_connect(). In this case, ps->sock is NULL, so we need to check
for this case in order to avoid dereferencing a NULL pointer.
Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault <g.nault(a)alphalink.fr>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
net/l2tp/l2tp_ppp.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -993,6 +993,9 @@ static int pppol2tp_session_ioctl(struct
session->name, cmd, arg);
sk = ps->sock;
+ if (!sk)
+ return -EBADR;
+
sock_hold(sk);
switch (cmd) {
Patches currently in stable-queue which might be from g.nault(a)alphalink.fr are
queue-4.9/ppp-fix-race-in-ppp-device-destruction.patch
queue-4.9/l2tp-check-ps-sock-before-running-pppol2tp_session_ioctl.patch
This is a note to let you know that I've just added the patch titled
ipv6: flowlabel: do not leave opt->tot_len with garbage
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
ipv6-flowlabel-do-not-leave-opt-tot_len-with-garbage.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Eric Dumazet <edumazet(a)google.com>
Date: Sat, 21 Oct 2017 12:26:23 -0700
Subject: ipv6: flowlabel: do not leave opt->tot_len with garbage
From: Eric Dumazet <edumazet(a)google.com>
[ Upstream commit 864e2a1f8aac05effac6063ce316b480facb46ff ]
When syzkaller team brought us a C repro for the crash [1] that
had been reported many times in the past, I finally could find
the root cause.
If FlowLabel info is merged by fl6_merge_options(), we leave
part of the opt_space storage provided by udp/raw/l2tp with random value
in opt_space.tot_len, unless a control message was provided at sendmsg()
time.
Then ip6_setup_cork() would use this random value to perform a kzalloc()
call. Undefined behavior and crashes.
Fix is to properly set tot_len in fl6_merge_options()
At the same time, we can also avoid consuming memory and cpu cycles
to clear it, if every option is copied via a kmemdup(). This is the
change in ip6_setup_cork().
[1]
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 6613 Comm: syz-executor0 Not tainted 4.14.0-rc4+ #127
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cb64a100 task.stack: ffff8801cc350000
RIP: 0010:ip6_setup_cork+0x274/0x15c0 net/ipv6/ip6_output.c:1168
RSP: 0018:ffff8801cc357550 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: ffff8801cc357748 RCX: 0000000000000010
RDX: 0000000000000002 RSI: ffffffff842bd1d9 RDI: 0000000000000014
RBP: ffff8801cc357620 R08: ffff8801cb17f380 R09: ffff8801cc357b10
R10: ffff8801cb64a100 R11: 0000000000000000 R12: ffff8801cc357ab0
R13: ffff8801cc357b10 R14: 0000000000000000 R15: ffff8801c3bbf0c0
FS: 00007f9c5c459700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020324000 CR3: 00000001d1cf2000 CR4: 00000000001406f0
DR0: 0000000020001010 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
ip6_make_skb+0x282/0x530 net/ipv6/ip6_output.c:1729
udpv6_sendmsg+0x2769/0x3380 net/ipv6/udp.c:1340
inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:762
sock_sendmsg_nosec net/socket.c:633 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:643
SYSC_sendto+0x358/0x5a0 net/socket.c:1750
SyS_sendto+0x40/0x50 net/socket.c:1718
entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x4520a9
RSP: 002b:00007f9c5c458c08 EFLAGS: 00000216 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 00000000004520a9
RDX: 0000000000000001 RSI: 0000000020fd1000 RDI: 0000000000000016
RBP: 0000000000000086 R08: 0000000020e0afe4 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004bb1ee
R13: 00000000ffffffff R14: 0000000000000016 R15: 0000000000000029
Code: e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 ea 0f 00 00 48 8d 79 04 48 b8 00 00 00 00 00 fc ff df 45 8b 74 24 04 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85
RIP: ip6_setup_cork+0x274/0x15c0 net/ipv6/ip6_output.c:1168 RSP: ffff8801cc357550
Signed-off-by: Eric Dumazet <edumazet(a)google.com>
Reported-by: Dmitry Vyukov <dvyukov(a)google.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
net/ipv6/ip6_flowlabel.c | 1 +
net/ipv6/ip6_output.c | 4 ++--
2 files changed, 3 insertions(+), 2 deletions(-)
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -315,6 +315,7 @@ struct ipv6_txoptions *fl6_merge_options
}
opt_space->dst1opt = fopt->dst1opt;
opt_space->opt_flen = fopt->opt_flen;
+ opt_space->tot_len = fopt->tot_len;
return opt_space;
}
EXPORT_SYMBOL_GPL(fl6_merge_options);
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1215,11 +1215,11 @@ static int ip6_setup_cork(struct sock *s
if (WARN_ON(v6_cork->opt))
return -EINVAL;
- v6_cork->opt = kzalloc(opt->tot_len, sk->sk_allocation);
+ v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation);
if (unlikely(!v6_cork->opt))
return -ENOBUFS;
- v6_cork->opt->tot_len = opt->tot_len;
+ v6_cork->opt->tot_len = sizeof(*opt);
v6_cork->opt->opt_flen = opt->opt_flen;
v6_cork->opt->opt_nflen = opt->opt_nflen;
Patches currently in stable-queue which might be from edumazet(a)google.com are
queue-4.9/net-call-cgroup_sk_alloc-earlier-in-sk_clone_lock.patch
queue-4.9/tcp-dccp-fix-ireq-opt-races.patch
queue-4.9/tcp-fix-tcp_mtu_probe-vs-highest_sack.patch
queue-4.9/ipv6-addrconf-increment-ifp-refcount-before-ipv6_del_addr.patch
queue-4.9/ipv6-flowlabel-do-not-leave-opt-tot_len-with-garbage.patch
queue-4.9/packet-avoid-panic-in-packet_getsockopt.patch
queue-4.9/sctp-add-the-missing-sock_owned_by_user-check-in-sctp_icmp_redirect.patch
queue-4.9/net_sched-avoid-matching-qdisc-with-zero-handle.patch
queue-4.9/tun-tap-sanitize-tunsetsndbuf-input.patch
queue-4.9/tcp-dccp-fix-lockdep-splat-in-inet_csk_route_req.patch
queue-4.9/tcp-dccp-fix-other-lockdep-splats-accessing-ireq_opt.patch
This is a note to let you know that I've just added the patch titled
ipip: only increase err_count for some certain type icmp in ipip_err
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
ipip-only-increase-err_count-for-some-certain-type-icmp-in-ipip_err.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Xin Long <lucien.xin(a)gmail.com>
Date: Thu, 26 Oct 2017 19:19:56 +0800
Subject: ipip: only increase err_count for some certain type icmp in ipip_err
From: Xin Long <lucien.xin(a)gmail.com>
[ Upstream commit f3594f0a7ea36661d7fd942facd7f31a64245f1a ]
t->err_count is used to count the link failure on tunnel and an err
will be reported to user socket in tx path if t->err_count is not 0.
udp socket could even return EHOSTUNREACH to users.
Since commit fd58156e456d ("IPIP: Use ip-tunneling code.") removed
the 'switch check' for icmp type in ipip_err(), err_count would be
increased by the icmp packet with ICMP_EXC_FRAGTIME code. an link
failure would be reported out due to this.
In Jianlin's case, when receiving ICMP_EXC_FRAGTIME a icmp packet,
udp netperf failed with the err:
send_data: data send error: No route to host (errno 113)
We expect this error reported from tunnel to socket when receiving
some certain type icmp, but not ICMP_EXC_FRAGTIME, ICMP_SR_FAILED
or ICMP_PARAMETERPROB ones.
This patch is to bring 'switch check' for icmp type back to ipip_err
so that it only reports link failure for the right type icmp, just as
in ipgre_err() and ipip6_err().
Fixes: fd58156e456d ("IPIP: Use ip-tunneling code.")
Reported-by: Jianlin Shi <jishi(a)redhat.com>
Signed-off-by: Xin Long <lucien.xin(a)gmail.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
net/ipv4/ipip.c | 59 +++++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 42 insertions(+), 17 deletions(-)
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -128,43 +128,68 @@ static struct rtnl_link_ops ipip_link_op
static int ipip_err(struct sk_buff *skb, u32 info)
{
-
-/* All the routers (except for Linux) return only
- 8 bytes of packet payload. It means, that precise relaying of
- ICMP in the real Internet is absolutely infeasible.
- */
+ /* All the routers (except for Linux) return only
+ * 8 bytes of packet payload. It means, that precise relaying of
+ * ICMP in the real Internet is absolutely infeasible.
+ */
struct net *net = dev_net(skb->dev);
struct ip_tunnel_net *itn = net_generic(net, ipip_net_id);
const struct iphdr *iph = (const struct iphdr *)skb->data;
- struct ip_tunnel *t;
- int err;
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
+ struct ip_tunnel *t;
+ int err = 0;
+
+ switch (type) {
+ case ICMP_DEST_UNREACH:
+ switch (code) {
+ case ICMP_SR_FAILED:
+ /* Impossible event. */
+ goto out;
+ default:
+ /* All others are translated to HOST_UNREACH.
+ * rfc2003 contains "deep thoughts" about NET_UNREACH,
+ * I believe they are just ether pollution. --ANK
+ */
+ break;
+ }
+ break;
+
+ case ICMP_TIME_EXCEEDED:
+ if (code != ICMP_EXC_TTL)
+ goto out;
+ break;
+
+ case ICMP_REDIRECT:
+ break;
+
+ default:
+ goto out;
+ }
- err = -ENOENT;
t = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
iph->daddr, iph->saddr, 0);
- if (!t)
+ if (!t) {
+ err = -ENOENT;
goto out;
+ }
if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
- ipv4_update_pmtu(skb, dev_net(skb->dev), info,
- t->parms.link, 0, iph->protocol, 0);
- err = 0;
+ ipv4_update_pmtu(skb, net, info, t->parms.link, 0,
+ iph->protocol, 0);
goto out;
}
if (type == ICMP_REDIRECT) {
- ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
- iph->protocol, 0);
- err = 0;
+ ipv4_redirect(skb, net, t->parms.link, 0, iph->protocol, 0);
goto out;
}
- if (t->parms.iph.daddr == 0)
+ if (t->parms.iph.daddr == 0) {
+ err = -ENOENT;
goto out;
+ }
- err = 0;
if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
goto out;
Patches currently in stable-queue which might be from lucien.xin(a)gmail.com are
queue-4.9/sctp-reset-owner-sk-for-data-chunks-on-out-queues-when-migrating-a-sock.patch
queue-4.9/ipip-only-increase-err_count-for-some-certain-type-icmp-in-ipip_err.patch
queue-4.9/sctp-full-support-for-ipv6-ip_nonlocal_bind-ip_freebind.patch
queue-4.9/sctp-add-the-missing-sock_owned_by_user-check-in-sctp_icmp_redirect.patch
queue-4.9/ip6_gre-only-increase-err_count-for-some-certain-type-icmpv6-in-ip6gre_err.patch
queue-4.9/ip6_gre-update-dst-pmtu-if-dev-mtu-has-been-updated-by-toobig-in-__gre6_xmit.patch