Skip to content

Commit 56c5ee1

Browse files
NicolasDichtelklassert
NicolasDichtel
authored and
klassert
committed
xfrm interface: fix memory leak on creation
The following commands produce a backtrace and return an error but the xfrm interface is created (in the wrong netns): $ ip netns add foo $ ip netns add bar $ ip -n foo netns set bar 0 $ ip -n foo link add xfrmi0 link-netnsid 0 type xfrm dev lo if_id 23 RTNETLINK answers: Invalid argument $ ip -n bar link ls xfrmi0 2: xfrmi0@lo: <NOARP,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/none 00:00:00:00:00:00 brd 00:00:00:00:00:00 Here is the backtrace: [ 79.879174] WARNING: CPU: 0 PID: 1178 at net/core/dev.c:8172 rollback_registered_many+0x86/0x3c1 [ 79.880260] Modules linked in: xfrm_interface nfsv3 nfs_acl auth_rpcgss nfsv4 nfs lockd grace sunrpc fscache button parport_pc parport serio_raw evdev pcspkr loop ext4 crc16 mbcache jbd2 crc32c_generic ide_cd_mod ide_gd_mod cdrom ata_$ eneric ata_piix libata scsi_mod 8139too piix psmouse i2c_piix4 ide_core 8139cp mii i2c_core floppy [ 79.883698] CPU: 0 PID: 1178 Comm: ip Not tainted 5.2.0-rc6+ torvalds#106 [ 79.884462] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 79.885447] RIP: 0010:rollback_registered_many+0x86/0x3c1 [ 79.886120] Code: 01 e8 d7 7d c6 ff 0f 0b 48 8b 45 00 4c 8b 20 48 8d 58 90 49 83 ec 70 48 8d 7b 70 48 39 ef 74 44 8a 83 d0 04 00 00 84 c0 75 1f <0f> 0b e8 61 cd ff ff 48 b8 00 01 00 00 00 00 ad de 48 89 43 70 66 [ 79.888667] RSP: 0018:ffffc900015ab740 EFLAGS: 00010246 [ 79.889339] RAX: ffff8882353e5700 RBX: ffff8882353e56a0 RCX: ffff8882353e5710 [ 79.890174] RDX: ffffc900015ab7e0 RSI: ffffc900015ab7e0 RDI: ffff8882353e5710 [ 79.891029] RBP: ffffc900015ab7e0 R08: ffffc900015ab7e0 R09: ffffc900015ab7e0 [ 79.891866] R10: ffffc900015ab7a0 R11: ffffffff82233fec R12: ffffc900015ab770 [ 79.892728] R13: ffffffff81eb7ec0 R14: ffff88822ed6cf00 R15: 00000000ffffffea [ 79.893557] FS: 00007ff350f31740(0000) GS:ffff888237a00000(0000) knlGS:0000000000000000 [ 79.894581] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 79.895317] CR2: 00000000006c8580 CR3: 000000022c272000 CR4: 00000000000006f0 [ 79.896137] Call Trace: [ 79.896464] unregister_netdevice_many+0x12/0x6c [ 79.896998] __rtnl_newlink+0x6e2/0x73b [ 79.897446] ? __kmalloc_node_track_caller+0x15e/0x185 [ 79.898039] ? pskb_expand_head+0x5f/0x1fe [ 79.898556] ? stack_access_ok+0xd/0x2c [ 79.899009] ? deref_stack_reg+0x12/0x20 [ 79.899462] ? stack_access_ok+0xd/0x2c [ 79.899927] ? stack_access_ok+0xd/0x2c [ 79.900404] ? __module_text_address+0x9/0x4f [ 79.900910] ? is_bpf_text_address+0x5/0xc [ 79.901390] ? kernel_text_address+0x67/0x7b [ 79.901884] ? __kernel_text_address+0x1a/0x25 [ 79.902397] ? unwind_get_return_address+0x12/0x23 [ 79.903122] ? __cmpxchg_double_slab.isra.37+0x46/0x77 [ 79.903772] rtnl_newlink+0x43/0x56 [ 79.904217] rtnetlink_rcv_msg+0x200/0x24c In fact, each time a xfrm interface was created, a netdev was allocated by __rtnl_newlink()/rtnl_create_link() and then another one by xfrmi_newlink()/xfrmi_create(). Only the second one was registered, it's why the previous commands produce a backtrace: dev_change_net_namespace() was called on a netdev with reg_state set to NETREG_UNINITIALIZED (the first one). CC: Lorenzo Colitti <lorenzo@google.com> CC: Benedict Wong <benedictwong@google.com> CC: Steffen Klassert <steffen.klassert@secunet.com> CC: Shannon Nelson <shannon.nelson@oracle.com> CC: Antony Antony <antony@phenome.org> CC: Eyal Birger <eyal.birger@gmail.com> Fixes: f203b76 ("xfrm: Add virtual xfrm interfaces") Reported-by: Julien Floret <julien.floret@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
1 parent fd70972 commit 56c5ee1

File tree

1 file changed

+28
-70
lines changed

1 file changed

+28
-70
lines changed

‎net/xfrm/xfrm_interface.c

+28-70
Original file line numberDiff line numberDiff line change
@@ -133,7 +133,7 @@ static void xfrmi_dev_free(struct net_device *dev)
133133
free_percpu(dev->tstats);
134134
}
135135

136-
static int xfrmi_create2(struct net_device *dev)
136+
static int xfrmi_create(struct net_device *dev)
137137
{
138138
struct xfrm_if *xi = netdev_priv(dev);
139139
struct net *net = dev_net(dev);
@@ -156,72 +156,19 @@ static int xfrmi_create2(struct net_device *dev)
156156
return err;
157157
}
158158

159-
static struct xfrm_if *xfrmi_create(struct net *net, struct xfrm_if_parms *p)
160-
{
161-
struct net_device *dev;
162-
struct xfrm_if *xi;
163-
char name[IFNAMSIZ];
164-
int err;
165-
166-
if (p->name[0]) {
167-
strlcpy(name, p->name, IFNAMSIZ);
168-
} else {
169-
err = -EINVAL;
170-
goto failed;
171-
}
172-
173-
dev = alloc_netdev(sizeof(*xi), name, NET_NAME_UNKNOWN, xfrmi_dev_setup);
174-
if (!dev) {
175-
err = -EAGAIN;
176-
goto failed;
177-
}
178-
179-
dev_net_set(dev, net);
180-
181-
xi = netdev_priv(dev);
182-
xi->p = *p;
183-
xi->net = net;
184-
xi->dev = dev;
185-
xi->phydev = dev_get_by_index(net, p->link);
186-
if (!xi->phydev) {
187-
err = -ENODEV;
188-
goto failed_free;
189-
}
190-
191-
err = xfrmi_create2(dev);
192-
if (err < 0)
193-
goto failed_dev_put;
194-
195-
return xi;
196-
197-
failed_dev_put:
198-
dev_put(xi->phydev);
199-
failed_free:
200-
free_netdev(dev);
201-
failed:
202-
return ERR_PTR(err);
203-
}
204-
205-
static struct xfrm_if *xfrmi_locate(struct net *net, struct xfrm_if_parms *p,
206-
int create)
159+
static struct xfrm_if *xfrmi_locate(struct net *net, struct xfrm_if_parms *p)
207160
{
208161
struct xfrm_if __rcu **xip;
209162
struct xfrm_if *xi;
210163
struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id);
211164

212165
for (xip = &xfrmn->xfrmi[0];
213166
(xi = rtnl_dereference(*xip)) != NULL;
214-
xip = &xi->next) {
215-
if (xi->p.if_id == p->if_id) {
216-
if (create)
217-
return ERR_PTR(-EEXIST);
218-
167+
xip = &xi->next)
168+
if (xi->p.if_id == p->if_id)
219169
return xi;
220-
}
221-
}
222-
if (!create)
223-
return ERR_PTR(-ENODEV);
224-
return xfrmi_create(net, p);
170+
171+
return NULL;
225172
}
226173

227174
static void xfrmi_dev_uninit(struct net_device *dev)
@@ -686,21 +633,33 @@ static int xfrmi_newlink(struct net *src_net, struct net_device *dev,
686633
struct netlink_ext_ack *extack)
687634
{
688635
struct net *net = dev_net(dev);
689-
struct xfrm_if_parms *p;
636+
struct xfrm_if_parms p;
690637
struct xfrm_if *xi;
638+
int err;
691639

692-
xi = netdev_priv(dev);
693-
p = &xi->p;
694-
695-
xfrmi_netlink_parms(data, p);
640+
xfrmi_netlink_parms(data, &p);
696641

697642
if (!tb[IFLA_IFNAME])
698643
return -EINVAL;
699644

700-
nla_strlcpy(p->name, tb[IFLA_IFNAME], IFNAMSIZ);
645+
nla_strlcpy(p.name, tb[IFLA_IFNAME], IFNAMSIZ);
701646

702-
xi = xfrmi_locate(net, p, 1);
703-
return PTR_ERR_OR_ZERO(xi);
647+
xi = xfrmi_locate(net, &p);
648+
if (xi)
649+
return -EEXIST;
650+
651+
xi = netdev_priv(dev);
652+
xi->p = p;
653+
xi->net = net;
654+
xi->dev = dev;
655+
xi->phydev = dev_get_by_index(net, p.link);
656+
if (!xi->phydev)
657+
return -ENODEV;
658+
659+
err = xfrmi_create(dev);
660+
if (err < 0)
661+
dev_put(xi->phydev);
662+
return err;
704663
}
705664

706665
static void xfrmi_dellink(struct net_device *dev, struct list_head *head)
@@ -717,9 +676,8 @@ static int xfrmi_changelink(struct net_device *dev, struct nlattr *tb[],
717676

718677
xfrmi_netlink_parms(data, &xi->p);
719678

720-
xi = xfrmi_locate(net, &xi->p, 0);
721-
722-
if (IS_ERR_OR_NULL(xi)) {
679+
xi = xfrmi_locate(net, &xi->p);
680+
if (!xi) {
723681
xi = netdev_priv(dev);
724682
} else {
725683
if (xi->dev != dev)

0 commit comments

Comments
 (0)