From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Hulk Robot <hulkci@huawei.com>,
Wei Yongjun <weiyongjun1@huawei.com>,
Eric Dumazet <edumazet@google.com>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.14 09/14] ip6_gre: fix null-ptr-deref in ip6gre_init_net()
Date: Thu, 30 Jul 2020 10:04:52 +0200 [thread overview]
Message-ID: <20200730074419.359661406@linuxfoundation.org> (raw)
In-Reply-To: <20200730074418.882736401@linuxfoundation.org>
From: Wei Yongjun <weiyongjun1@huawei.com>
[ Upstream commit 46ef5b89ec0ecf290d74c4aee844f063933c4da4 ]
KASAN report null-ptr-deref error when register_netdev() failed:
KASAN: null-ptr-deref in range [0x00000000000003c0-0x00000000000003c7]
CPU: 2 PID: 422 Comm: ip Not tainted 5.8.0-rc4+ #12
Call Trace:
ip6gre_init_net+0x4ab/0x580
? ip6gre_tunnel_uninit+0x3f0/0x3f0
ops_init+0xa8/0x3c0
setup_net+0x2de/0x7e0
? rcu_read_lock_bh_held+0xb0/0xb0
? ops_init+0x3c0/0x3c0
? kasan_unpoison_shadow+0x33/0x40
? __kasan_kmalloc.constprop.0+0xc2/0xd0
copy_net_ns+0x27d/0x530
create_new_namespaces+0x382/0xa30
unshare_nsproxy_namespaces+0xa1/0x1d0
ksys_unshare+0x39c/0x780
? walk_process_tree+0x2a0/0x2a0
? trace_hardirqs_on+0x4a/0x1b0
? _raw_spin_unlock_irq+0x1f/0x30
? syscall_trace_enter+0x1a7/0x330
? do_syscall_64+0x1c/0xa0
__x64_sys_unshare+0x2d/0x40
do_syscall_64+0x56/0xa0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
ip6gre_tunnel_uninit() has set 'ign->fb_tunnel_dev' to NULL, later
access to ign->fb_tunnel_dev cause null-ptr-deref. Fix it by saving
'ign->fb_tunnel_dev' to local variable ndev.
Fixes: dafabb6590cb ("ip6_gre: fix use-after-free in ip6gre_tunnel_lookup()")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv6/ip6_gre.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -1169,15 +1169,16 @@ static void ip6gre_destroy_tunnels(struc
static int __net_init ip6gre_init_net(struct net *net)
{
struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
+ struct net_device *ndev;
int err;
- ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
- NET_NAME_UNKNOWN,
- ip6gre_tunnel_setup);
- if (!ign->fb_tunnel_dev) {
+ ndev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0",
+ NET_NAME_UNKNOWN, ip6gre_tunnel_setup);
+ if (!ndev) {
err = -ENOMEM;
goto err_alloc_dev;
}
+ ign->fb_tunnel_dev = ndev;
dev_net_set(ign->fb_tunnel_dev, net);
/* FB netdevice is special: we have one, and only one per netns.
* Allowing to move it to another netns is clearly unsafe.
@@ -1197,7 +1198,7 @@ static int __net_init ip6gre_init_net(st
return 0;
err_reg_dev:
- free_netdev(ign->fb_tunnel_dev);
+ free_netdev(ndev);
err_alloc_dev:
return err;
}
next prev parent reply other threads:[~2020-07-30 8:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-30 8:04 [PATCH 4.14 00/14] 4.14.191-rc1 review Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 01/14] AX.25: Fix out-of-bounds read in ax25_connect() Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 02/14] AX.25: Prevent out-of-bounds read in ax25_sendmsg() Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 03/14] dev: Defer free of skbs in flush_backlog Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 04/14] drivers/net/wan/x25_asy: Fix to make it work Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 05/14] net-sysfs: add a newline when printing tx_timeout by sysfs Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 06/14] net: udp: Fix wrong clean up for IS_UDPLITE macro Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 07/14] rxrpc: Fix sendmsg() returning EPIPE due to recvmsg() returning ENODATA Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 08/14] AX.25: Prevent integer overflows in connect and sendmsg Greg Kroah-Hartman
2020-07-30 8:04 ` Greg Kroah-Hartman [this message]
2020-07-30 8:04 ` [PATCH 4.14 10/14] rtnetlink: Fix memory(net_device) leak when ->newlink fails Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 11/14] tcp: allow at most one TLP probe per flight Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 12/14] mm/page_owner.c: remove drain_all_pages from init_early_allocated_pages Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 13/14] regmap: debugfs: check count when read regmap file Greg Kroah-Hartman
2020-07-30 8:04 ` [PATCH 4.14 14/14] xfs: set format back to extents if xfs_bmap_extents_to_btree Greg Kroah-Hartman
2020-07-30 16:47 ` [PATCH 4.14 00/14] 4.14.191-rc1 review Guenter Roeck
2020-07-31 12:15 ` Naresh Kamboju
2020-07-31 12:42 ` Jon Hunter
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