user/sven/linux.git/include, branch v4.3.3

ext4, jbd2: ensure entering into panic after recording an error in superblock

2015-12-15T05:41:07Z

commit 4327ba52afd03fc4b5afa0ee1d774c9c5b0e85c5 upstream. If a EXT4 filesystem utilizes JBD2 journaling and an error occurs, the journaling will be aborted first and the error number will be recorded into JBD2 superblock and, finally, the system will enter into the panic state in "errors=panic" option. But, in the rare case, this sequence is little twisted like the below figure and it will happen that the system enters into panic state, which means the system reset in mobile environment, before completion of recording an error in the journal superblock. In this case, e2fsck cannot recognize that the filesystem failure occurred in the previous run and the corruption wouldn't be fixed. Task A Task B ext4_handle_error() -> jbd2_journal_abort() -> __journal_abort_soft() -> __jbd2_journal_abort_hard() | -> journal->j_flags |= JBD2_ABORT; | | __ext4_abort() | -> jbd2_journal_abort() | | -> __journal_abort_soft() | | -> if (journal->j_flags & JBD2_ABORT) | | return; | -> panic() | -> jbd2_journal_update_sb_errno() Tested-by: Hobin Woo Signed-off-by: Daeho Jeong Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

net_sched: fix qdisc_tree_decrease_qlen() races

2015-12-15T05:41:04Z

[ Upstream commit 4eaf3b84f2881c9c028f1d5e76c52ab575fe3a66 ] qdisc_tree_decrease_qlen() suffers from two problems on multiqueue devices. One problem is that it updates sch->q.qlen and sch->qstats.drops on the mq/mqprio root qdisc, while it should not : Daniele reported underflows errors : [ 681.774821] PAX: sch->q.qlen: 0 n: 1 [ 681.774825] PAX: size overflow detected in function qdisc_tree_decrease_qlen net/sched/sch_api.c:769 cicus.693_49 min, count: 72, decl: qlen; num: 0; context: sk_buff_head; [ 681.774954] CPU: 2 PID: 19 Comm: ksoftirqd/2 Tainted: G O 4.2.6.201511282239-1-grsec #1 [ 681.774955] Hardware name: ASUSTeK COMPUTER INC. X302LJ/X302LJ, BIOS X302LJ.202 03/05/2015 [ 681.774956] ffffffffa9a04863 0000000000000000 0000000000000000 ffffffffa990ff7c [ 681.774959] ffffc90000d3bc38 ffffffffa95d2810 0000000000000007 ffffffffa991002b [ 681.774960] ffffc90000d3bc68 ffffffffa91a44f4 0000000000000001 0000000000000001 [ 681.774962] Call Trace: [ 681.774967] [] dump_stack+0x4c/0x7f [ 681.774970] [] report_size_overflow+0x34/0x50 [ 681.774972] [] qdisc_tree_decrease_qlen+0x152/0x160 [ 681.774976] [] fq_codel_dequeue+0x7b1/0x820 [sch_fq_codel] [ 681.774978] [] ? qdisc_peek_dequeued+0xa0/0xa0 [sch_fq_codel] [ 681.774980] [] __qdisc_run+0x4d/0x1d0 [ 681.774983] [] net_tx_action+0xc2/0x160 [ 681.774985] [] __do_softirq+0xf1/0x200 [ 681.774987] [] run_ksoftirqd+0x1e/0x30 [ 681.774989] [] smpboot_thread_fn+0x150/0x260 [ 681.774991] [] ? sort_range+0x40/0x40 [ 681.774992] [] kthread+0xe4/0x100 [ 681.774994] [] ? kthread_worker_fn+0x170/0x170 [ 681.774995] [] ret_from_fork+0x3e/0x70 mq/mqprio have their own ways to report qlen/drops by folding stats on all their queues, with appropriate locking. A second problem is that qdisc_tree_decrease_qlen() calls qdisc_lookup() without proper locking : concurrent qdisc updates could corrupt the list that qdisc_match_from_root() parses to find a qdisc given its handle. Fix first problem adding a TCQ_F_NOPARENT qdisc flag that qdisc_tree_decrease_qlen() can use to abort its tree traversal, as soon as it meets a mq/mqprio qdisc children. Second problem can be fixed by RCU protection. Qdisc are already freed after RCU grace period, so qdisc_list_add() and qdisc_list_del() simply have to use appropriate rcu list variants. A future patch will add a per struct netdev_queue list anchor, so that qdisc_tree_decrease_qlen() can have more efficient lookups. Reported-by: Daniele Fucini Signed-off-by: Eric Dumazet Cc: Cong Wang Cc: Jamal Hadi Salim Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv6: add complete rcu protection around np->opt

2015-12-15T05:41:04Z

[ Upstream commit 45f6fad84cc305103b28d73482b344d7f5b76f39 ] This patch addresses multiple problems : UDP/RAW sendmsg() need to get a stable struct ipv6_txoptions while socket is not locked : Other threads can change np->opt concurrently. Dmitry posted a syzkaller (http://github.com/google/syzkaller) program desmonstrating use-after-free. Starting with TCP/DCCP lockless listeners, tcp_v6_syn_recv_sock() and dccp_v6_request_recv_sock() also need to use RCU protection to dereference np->opt once (before calling ipv6_dup_options()) This patch adds full RCU protection to np->opt Reported-by: Dmitry Vyukov Signed-off-by: Eric Dumazet Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv6: distinguish frag queues by device for multicast and link-local packets

2015-12-15T05:41:03Z

[ Upstream commit 264640fc2c5f4f913db5c73fa3eb1ead2c45e9d7 ] If a fragmented multicast packet is received on an ethernet device which has an active macvlan on top of it, each fragment is duplicated and received both on the underlying device and the macvlan. If some fragments for macvlan are processed before the whole packet for the underlying device is reassembled, the "overlapping fragments" test in ip6_frag_queue() discards the whole fragment queue. To resolve this, add device ifindex to the search key and require it to match reassembling multicast packets and packets to link-local addresses. Note: similar patch has been already submitted by Yoshifuji Hideaki in http://patchwork.ozlabs.org/patch/220979/ but got lost and forgotten for some reason. Signed-off-by: Michal Kubecek Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: switchdev: fix return code of fdb_dump stub

2015-12-15T05:40:59Z

[ Upstream commit 24cb7055a3066634a0f3fa0cd6a4780652905d35 ] rtnl_fdb_dump always expects an index to be returned by the ndo_fdb_dump op, but when CONFIG_NET_SWITCHDEV is off, it returns an error. Fix that by returning the given unmodified idx. A similar fix was 0890cf6cb6ab ("switchdev: fix return value of switchdev_port_fdb_dump in case of error") but for the CONFIG_NET_SWITCHDEV=y case. Fixes: 45d4122ca7cd ("switchdev: add support for fdb add/del/dump via switchdev_port_obj ops.") Signed-off-by: Dragos Tatulea Acked-by: Jiri Pirko Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ip_tunnel: disable preemption when updating per-cpu tstats

2015-12-15T05:40:59Z

[ Upstream commit b4fe85f9c9146f60457e9512fb6055e69e6a7a65 ] Drivers like vxlan use the recently introduced udp_tunnel_xmit_skb/udp_tunnel6_xmit_skb APIs. udp_tunnel6_xmit_skb makes use of ip6tunnel_xmit, and ip6tunnel_xmit, after sending the packet, updates the struct stats using the usual u64_stats_update_begin/end calls on this_cpu_ptr(dev->tstats). udp_tunnel_xmit_skb makes use of iptunnel_xmit, which doesn't touch tstats, so drivers like vxlan, immediately after, call iptunnel_xmit_stats, which does the same thing - calls u64_stats_update_begin/end on this_cpu_ptr(dev->tstats). While vxlan is probably fine (I don't know?), calling a similar function from, say, an unbound workqueue, on a fully preemptable kernel causes real issues: [ 188.434537] BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u8:0/6 [ 188.435579] caller is debug_smp_processor_id+0x17/0x20 [ 188.435583] CPU: 0 PID: 6 Comm: kworker/u8:0 Not tainted 4.2.6 #2 [ 188.435607] Call Trace: [ 188.435611] [] dump_stack+0x4f/0x7b [ 188.435615] [] check_preemption_disabled+0x19d/0x1c0 [ 188.435619] [] debug_smp_processor_id+0x17/0x20 The solution would be to protect the whole this_cpu_ptr(dev->tstats)/u64_stats_update_begin/end blocks with disabling preemption and then reenabling it. Signed-off-by: Jason A. Donenfeld Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net/mlx5e: Added self loopback prevention

2015-12-15T05:40:58Z

[ Upstream commit 66189961e986e53ae39822898fc2ce88f44c61bb ] Prevent outgoing multicast frames from looping back to the RX queue. By introducing new HW capability self_lb_en_modifiable, which indicates the support to modify self_lb_en bit in modify_tir command. When this capability is set we can prevent TIRs from sending back loopback multicast traffic to their own RQs, by "refreshing TIRs" with modify_tir command, on every time new channels (SQs/RQs) are created at device open. This is needed since TIRs are static and only allocated once on driver load, and the loopback decision is under their responsibility. Fixes issues of the kind: "IPv6: eth2: IPv6 duplicate address fe80::e61d:2dff:fe5c:f2e9 detected!" The issue is seen since the IPv6 solicitations multicast messages are loopedback and the network stack thinks they are coming from another host. Fixes: 5c50368f3831 ("net/mlx5e: Light-weight netdev open/stop") Signed-off-by: Tariq Toukan Signed-off-by: Saeed Mahameed Signed-off-by: Or Gerlitz Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

Revert "ipv6: ndisc: inherit metadata dst when creating ndisc requests"

2015-12-15T05:40:56Z

[ Upstream commit 304d888b29cf96f1dd53511ee686499cd8cdf249 ] This reverts commit ab450605b35caa768ca33e86db9403229bf42be4. In IPv6, we cannot inherit the dst of the original dst. ndisc packets are IPv6 packets and may take another route than the original packet. This patch breaks the following scenario: a packet comes from eth0 and is forwarded through vxlan1. The encapsulated packet triggers an NS which cannot be sent because of the wrong route. CC: Jiri Benc CC: Thomas Graf Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv6: Check rt->dst.from for the DST_NOCACHE route

2015-12-15T05:40:56Z

[ Upstrem commit 02bcf4e082e4dc634409a6a6cb7def8806d6e5e6 ] All DST_NOCACHE rt6_info used to have rt->dst.from set to its parent. After commit 8e3d5be73681 ("ipv6: Avoid double dst_free"), DST_NOCACHE is also set to rt6_info which does not have a parent (i.e. rt->dst.from is NULL). This patch catches the rt->dst.from == NULL case. Fixes: 8e3d5be73681 ("ipv6: Avoid double dst_free") Signed-off-by: Martin KaFai Lau Cc: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

unix: avoid use-after-free in ep_remove_wait_queue

2015-12-15T05:40:55Z

[ Upstream commit 7d267278a9ece963d77eefec61630223fce08c6c ] Rainer Weikusat writes: An AF_UNIX datagram socket being the client in an n:1 association with some server socket is only allowed to send messages to the server if the receive queue of this socket contains at most sk_max_ack_backlog datagrams. This implies that prospective writers might be forced to go to sleep despite none of the message presently enqueued on the server receive queue were sent by them. In order to ensure that these will be woken up once space becomes again available, the present unix_dgram_poll routine does a second sock_poll_wait call with the peer_wait wait queue of the server socket as queue argument (unix_dgram_recvmsg does a wake up on this queue after a datagram was received). This is inherently problematic because the server socket is only guaranteed to remain alive for as long as the client still holds a reference to it. In case the connection is dissolved via connect or by the dead peer detection logic in unix_dgram_sendmsg, the server socket may be freed despite "the polling mechanism" (in particular, epoll) still has a pointer to the corresponding peer_wait queue. There's no way to forcibly deregister a wait queue with epoll. Based on an idea by Jason Baron, the patch below changes the code such that a wait_queue_t belonging to the client socket is enqueued on the peer_wait queue of the server whenever the peer receive queue full condition is detected by either a sendmsg or a poll. A wake up on the peer queue is then relayed to the ordinary wait queue of the client socket via wake function. The connection to the peer wait queue is again dissolved if either a wake up is about to be relayed or the client socket reconnects or a dead peer is detected or the client socket is itself closed. This enables removing the second sock_poll_wait from unix_dgram_poll, thus avoiding the use-after-free, while still ensuring that no blocked writer sleeps forever. Signed-off-by: Rainer Weikusat Fixes: ec0d215f9420 ("af_unix: fix 'poll for write'/connected DGRAM sockets") Reviewed-by: Jason Baron Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman