From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Ben Greear <greearb@candelatech.com>,
Eric Dumazet <edumazet@google.com>,
"David S. Miller" <davem@davemloft.net>
Subject: [ 18/36] net: loopback: fix a dst refcounting issue
Date: Tue, 12 Feb 2013 12:41:12 -0800 [thread overview]
Message-ID: <20130212203859.457340717@linuxfoundation.org> (raw)
In-Reply-To: <20130212203857.305594226@linuxfoundation.org>
3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@google.com>
[ Upstream commit 794ed393b707f01858f5ebe2ae5eabaf89d00022 ]
Ben Greear reported crashes in ip_rcv_finish() on a stress
test involving many macvlans.
We tracked the bug to a dst use after free. ip_rcv_finish()
was calling dst->input() and got garbage for dst->input value.
It appears the bug is in loopback driver, lacking
a skb_dst_force() before calling netif_rx().
As a result, a non refcounted dst, normally protected by a
RCU read_lock section, was escaping this section and could
be freed before the packet being processed.
[<ffffffff813a3c4d>] loopback_xmit+0x64/0x83
[<ffffffff81477364>] dev_hard_start_xmit+0x26c/0x35e
[<ffffffff8147771a>] dev_queue_xmit+0x2c4/0x37c
[<ffffffff81477456>] ? dev_hard_start_xmit+0x35e/0x35e
[<ffffffff8148cfa6>] ? eth_header+0x28/0xb6
[<ffffffff81480f09>] neigh_resolve_output+0x176/0x1a7
[<ffffffff814ad835>] ip_finish_output2+0x297/0x30d
[<ffffffff814ad6d5>] ? ip_finish_output2+0x137/0x30d
[<ffffffff814ad90e>] ip_finish_output+0x63/0x68
[<ffffffff814ae412>] ip_output+0x61/0x67
[<ffffffff814ab904>] dst_output+0x17/0x1b
[<ffffffff814adb6d>] ip_local_out+0x1e/0x23
[<ffffffff814ae1c4>] ip_queue_xmit+0x315/0x353
[<ffffffff814adeaf>] ? ip_send_unicast_reply+0x2cc/0x2cc
[<ffffffff814c018f>] tcp_transmit_skb+0x7ca/0x80b
[<ffffffff814c3571>] tcp_connect+0x53c/0x587
[<ffffffff810c2f0c>] ? getnstimeofday+0x44/0x7d
[<ffffffff810c2f56>] ? ktime_get_real+0x11/0x3e
[<ffffffff814c6f9b>] tcp_v4_connect+0x3c2/0x431
[<ffffffff814d6913>] __inet_stream_connect+0x84/0x287
[<ffffffff814d6b38>] ? inet_stream_connect+0x22/0x49
[<ffffffff8108d695>] ? _local_bh_enable_ip+0x84/0x9f
[<ffffffff8108d6c8>] ? local_bh_enable+0xd/0x11
[<ffffffff8146763c>] ? lock_sock_nested+0x6e/0x79
[<ffffffff814d6b38>] ? inet_stream_connect+0x22/0x49
[<ffffffff814d6b49>] inet_stream_connect+0x33/0x49
[<ffffffff814632c6>] sys_connect+0x75/0x98
This bug was introduced in linux-2.6.35, in commit
7fee226ad2397b (net: add a noref bit on skb dst)
skb_dst_force() is enforced in dev_queue_xmit() for devices having a
qdisc.
Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/loopback.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -77,6 +77,11 @@ static netdev_tx_t loopback_xmit(struct
skb_orphan(skb);
+ /* Before queueing this packet to netif_rx(),
+ * make sure dst is refcounted.
+ */
+ skb_dst_force(skb);
+
skb->protocol = eth_type_trans(skb, dev);
/* it's OK to use per_cpu_ptr() because BHs are off */
next prev parent reply other threads:[~2013-02-12 20:41 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-12 20:40 [ 00/36] 3.4.31-stable review Greg Kroah-Hartman
2013-02-12 20:40 ` [ 01/36] rtlwifi: Fix the usage of the wrong variable in usb.c Greg Kroah-Hartman
2013-02-12 20:40 ` [ 02/36] rtlwifi: Fix scheduling while atomic bug Greg Kroah-Hartman
2013-02-12 20:40 ` [ 03/36] virtio_console: Dont access uninitialized data Greg Kroah-Hartman
2013-02-12 20:40 ` [ 04/36] kernel/resource.c: fix stack overflow in __reserve_region_with_split() Greg Kroah-Hartman
2013-02-12 20:40 ` [ 05/36] Bluetooth: Fix handling of unexpected SMP PDUs Greg Kroah-Hartman
2013-02-12 20:41 ` [ 06/36] efi: Make efi_enabled a function to query EFI facilities Greg Kroah-Hartman
2013-02-12 20:41 ` [ 07/36] samsung-laptop: Disable on EFI hardware Greg Kroah-Hartman
2013-02-12 20:41 ` [ 08/36] net: prevent setting ttl=0 via IP_TTL Greg Kroah-Hartman
2013-02-12 20:41 ` [ 09/36] ipv6: fix the noflags test in addrconf_get_prefix_route Greg Kroah-Hartman
2013-02-12 20:41 ` [ 10/36] MAINTAINERS: Stephen Hemminger email change Greg Kroah-Hartman
2013-02-12 20:41 ` [ 11/36] ipv6: fix header length calculation in ip6_append_data() Greg Kroah-Hartman
2013-02-12 20:41 ` [ 12/36] net: calxedaxgmac: throw away overrun frames Greg Kroah-Hartman
2013-02-12 20:41 ` [ 13/36] net/mlx4_en: Fix bridged vSwitch configuration for non SRIOV mode Greg Kroah-Hartman
2013-02-12 20:41 ` [ 14/36] net/mlx4_core: Set number of msix vectors under SRIOV mode to firmware defaults Greg Kroah-Hartman
2013-02-12 20:41 ` [ 15/36] isdn/gigaset: fix zero size border case in debug dump Greg Kroah-Hartman
2013-02-12 20:41 ` [ 16/36] netxen: fix off by one bug in netxen_release_tx_buffer() Greg Kroah-Hartman
2013-02-12 20:41 ` [ 17/36] r8169: remove the obsolete and incorrect AMD workaround Greg Kroah-Hartman
2013-02-12 20:41 ` Greg Kroah-Hartman [this message]
2013-02-12 20:41 ` [ 19/36] pktgen: correctly handle failures when adding a device Greg Kroah-Hartman
2013-02-12 20:41 ` [ 20/36] ipv6: do not create neighbor entries for local delivery Greg Kroah-Hartman
2013-02-12 20:41 ` [ 21/36] via-rhine: Fix bugs in NAPI support Greg Kroah-Hartman
2013-02-12 20:41 ` [ 22/36] packet: fix leakage of tx_ring memory Greg Kroah-Hartman
2013-02-12 20:41 ` [ 23/36] atm/iphase: rename fregt_t -> ffreg_t Greg Kroah-Hartman
2013-02-12 20:41 ` [ 24/36] sctp: refactor sctp_outq_teardown to insure proper re-initalization Greg Kroah-Hartman
2013-02-12 20:41 ` [ 25/36] net: sctp: sctp_setsockopt_auth_key: use kzfree instead of kfree Greg Kroah-Hartman
2013-02-12 20:41 ` [ 26/36] net: sctp: sctp_endpoint_free: zero out secret key data Greg Kroah-Hartman
2013-02-12 20:41 ` [ 27/36] xen/netback: shutdown the ring if it contains garbage Greg Kroah-Hartman
2013-02-12 20:41 ` [ 28/36] xen/netback: dont leak pages on failure in xen_netbk_tx_check_gop Greg Kroah-Hartman
2013-02-12 20:41 ` [ 29/36] xen/netback: free already allocated memory on failure in xen_netbk_get_requests Greg Kroah-Hartman
2013-02-12 20:41 ` [ 30/36] netback: correct netbk_tx_err to handle wrap around Greg Kroah-Hartman
2013-02-12 20:41 ` [ 31/36] tcp: frto should not set snd_cwnd to 0 Greg Kroah-Hartman
2013-02-12 20:41 ` [ 32/36] tcp: fix for zero packets_in_flight was too broad Greg Kroah-Hartman
2013-02-12 20:41 ` [ 33/36] bridge: Pull ip header into skb->data before looking into ip header Greg Kroah-Hartman
2013-02-12 20:41 ` [ 34/36] tg3: Avoid null pointer dereference in tg3_interrupt in netconsole mode Greg Kroah-Hartman
2013-02-12 20:41 ` [ 35/36] tg3: Fix crc errors on jumbo frame receive Greg Kroah-Hartman
2013-02-12 20:41 ` [ 36/36] be2net: Fix to trim skb for padded vlan packets to workaround an ASIC Bug Greg Kroah-Hartman
2013-02-13 9:23 ` [ 00/36] 3.4.31-stable review Satoru Takeuchi
2013-02-13 15:52 ` Shuah Khan
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