BMC/Intel-BMC/linux.git/net/dccp/ipv6.c, branch dev-4.6

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-02-23T05:09:14+00:00

Conflicts: drivers/net/phy/bcm7xxx.c drivers/net/phy/marvell.c drivers/net/vxlan.c All three conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller

tcp/dccp: fix another race at listener dismantle

2016-02-18T16:35:51+00:00

Ilya reported following lockdep splat: kernel: ========================= kernel: [ BUG: held lock freed! ] kernel: 4.5.0-rc1-ceph-00026-g5e0a311 #1 Not tainted kernel: ------------------------- kernel: swapper/5/0 is freeing memory ffff880035c9d200-ffff880035c9dbff, with a lock still held there! kernel: (&(&queue->rskq_lock)->rlock){+.-...}, at: [] inet_csk_reqsk_queue_add+0x28/0xa0 kernel: 4 locks held by swapper/5/0: kernel: #0: (rcu_read_lock){......}, at: [] netif_receive_skb_internal+0x4b/0x1f0 kernel: #1: (rcu_read_lock){......}, at: [] ip_local_deliver_finish+0x3f/0x380 kernel: #2: (slock-AF_INET){+.-...}, at: [] sk_clone_lock+0x19b/0x440 kernel: #3: (&(&queue->rskq_lock)->rlock){+.-...}, at: [] inet_csk_reqsk_queue_add+0x28/0xa0 To properly fix this issue, inet_csk_reqsk_queue_add() needs to return to its callers if the child as been queued into accept queue. We also need to make sure listener is still there before calling sk->sk_data_ready(), by holding a reference on it, since the reference carried by the child can disappear as soon as the child is put on accept queue. Reported-by: Ilya Dryomov Fixes: ebb516af60e1 ("tcp/dccp: fix race at listener dismantle phase") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

inet: refactor inet[6]_lookup functions to take skb

2016-02-11T08:54:14+00:00

This is a preliminary step to allow fast socket lookup of SO_REUSEPORT groups. Doing so with a BPF filter will require access to the skb in question. This change plumbs the skb (and offset to payload data) through the call stack to the listening socket lookup implementations where it will be used in a following patch. Signed-off-by: Craig Gallek Signed-off-by: David S. Miller

inet: create IPv6-equivalent inet_hash function

2016-02-11T08:54:14+00:00

In order to support fast lookups for TCP sockets with SO_REUSEPORT, the function that adds sockets to the listening hash set needs to be able to check receive address equality. Since this equality check is different for IPv4 and IPv6, we will need two different socket hashing functions. This patch adds inet6_hash identical to the existing inet_hash function and updates the appropriate references. A following patch will differentiate the two by passing different comparison functions to __inet_hash. Additionally, in order to use the IPv6 address equality function from inet6_hashtables (which is compiled as a built-in object when IPv6 is enabled) it also needs to be in a built-in object file as well. This moves ipv6_rcv_saddr_equal into inet_hashtables to accomplish this. Signed-off-by: Craig Gallek Signed-off-by: David S. Miller

ipv6: kill sk_dst_lock

2015-12-03T16:32:06+00:00

While testing the np->opt RCU conversion, I found that UDP/IPv6 was using a mixture of xchg() and sk_dst_lock to protect concurrent changes to sk->sk_dst_cache, leading to possible corruptions and crashes. ip6_sk_dst_lookup_flow() uses sk_dst_check() anyway, so the simplest way to fix the mess is to remove sk_dst_lock completely, as we did for IPv4. __ip6_dst_store() and ip6_dst_store() share same implementation. sk_setup_caps() being called with socket lock being held or not, we have to use sk_dst_set() instead of __sk_dst_set() Note that I had to move the "np->dst_cookie = rt6_get_cookie(rt);" in ip6_dst_store() before the sk_setup_caps(sk, dst) call. This is because ip6_dst_store() can be called from process context, without any lock held. As soon as the dst is installed in sk->sk_dst_cache, dst can be freed from another cpu doing a concurrent ip6_dst_store() Doing the dst dereference before doing the install is needed to make sure no use after free would trigger. Signed-off-by: Eric Dumazet Reported-by: Dmitry Vyukov Signed-off-by: David S. Miller

ipv6: add complete rcu protection around np->opt

2015-12-03T04:37:16+00:00

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

tcp/dccp: fix ireq->pktopts race

2015-11-02T20:38:26+00:00

IPv6 request sockets store a pointer to skb containing the SYN packet to be able to transfer it to full blown socket when 3WHS is done (ireq->pktopts -> np->pktoptions) As explained in commit 5e0724d027f0 ("tcp/dccp: fix hashdance race for passive sessions"), we must transfer the skb only if we won the hashdance race, if multiple cpus receive the 'ack' packet completing 3WHS at the same time. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp/dccp: fix hashdance race for passive sessions

2015-10-23T12:42:21+00:00

Multiple cpus can process duplicates of incoming ACK messages matching a SYN_RECV request socket. This is a rare event under normal operations, but definitely can happen. Only one must win the race, otherwise corruption would occur. To fix this without adding new atomic ops, we use logic in inet_ehash_nolisten() to detect the request was present in the same ehash bucket where we try to insert the new child. If request socket was not found, we have to undo the child creation. This actually removes a spin_lock()/spin_unlock() pair in reqsk_queue_unlink() for the fast path. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp/dccp: add inet_csk_reqsk_queue_drop_and_put() helper

2015-10-16T07:52:18+00:00

Let's reduce the confusion about inet_csk_reqsk_queue_drop() : In many cases we also need to release reference on request socket, so add a helper to do this, reducing code size and complexity. Fixes: 4bdc3d66147b ("tcp/dccp: fix behavior of stale SYN_RECV request sockets") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp/dccp: fix behavior of stale SYN_RECV request sockets

2015-10-14T01:26:34+00:00

When a TCP/DCCP listener is closed, its pending SYN_RECV request sockets become stale, meaning 3WHS can not complete. But current behavior is wrong : incoming packets finding such stale sockets are dropped. We need instead to cleanup the request socket and perform another lookup : - Incoming ACK will give a RST answer, - SYN rtx might find another listener if available. - We expedite cleanup of request sockets and old listener socket. Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller