kernel.git/net/dccp/ipv4.c, branch linux-4.12.y

dccp: fix a memleak that dccp_ipv4 doesn't put reqsk properly

2017-08-11T15:33:57Z

[ Upstream commit b7953d3c0e30a5fc944f6b7bd0bcceb0794bcd85 ] The patch "dccp: fix a memleak that dccp_ipv6 doesn't put reqsk properly" fixed reqsk refcnt leak for dccp_ipv6. The same issue exists on dccp_ipv4. This patch is to fix it for dccp_ipv4. Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

2017-04-23T09:12:44Z

Pull RCU updates from Paul E. McKenney: - Documentation updates. - Miscellaneous fixes. - Parallelize SRCU callback handling (plus overlapping patches). Signed-off-by: Ingo Molnar

mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU

2017-04-18T18:42:36Z

A group of Linux kernel hackers reported chasing a bug that resulted from their assumption that SLAB_DESTROY_BY_RCU provided an existence guarantee, that is, that no block from such a slab would be reallocated during an RCU read-side critical section. Of course, that is not the case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire slab of blocks. However, there is a phrase for this, namely "type safety". This commit therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order to avoid future instances of this sort of confusion. Signed-off-by: Paul E. McKenney Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Andrew Morton Cc: Acked-by: Johannes Weiner Acked-by: Vlastimil Babka [ paulmck: Add comments mentioning the old name, as requested by Eric Dumazet, in order to help people familiar with the old name find the new one. ] Acked-by: David Rientjes

dccp/tcp: fix routing redirect race

2017-03-14T04:55:47Z

As Eric Dumazet pointed out this also needs to be fixed in IPv6. v2: Contains the IPv6 tcp/Ipv6 dccp patches as well. We have seen a few incidents lately where a dst_enty has been freed with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that dst_entry. If the conditions/timings are right a crash then ensues when the freed dst_entry is referenced later on. A Common crashing back trace is: #8 [] page_fault at ffffffff8163e648 [exception RIP: __tcp_ack_snd_check+74] . . #9 [] tcp_rcv_established at ffffffff81580b64 #10 [] tcp_v4_do_rcv at ffffffff8158b54a #11 [] tcp_v4_rcv at ffffffff8158cd02 #12 [] ip_local_deliver_finish at ffffffff815668f4 #13 [] ip_local_deliver at ffffffff81566bd9 #14 [] ip_rcv_finish at ffffffff8156656d #15 [] ip_rcv at ffffffff81566f06 #16 [] __netif_receive_skb_core at ffffffff8152b3a2 #17 [] __netif_receive_skb at ffffffff8152b608 #18 [] netif_receive_skb at ffffffff8152b690 #19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3] #20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3] #21 [] net_rx_action at ffffffff8152bac2 #22 [] __do_softirq at ffffffff81084b4f #23 [] call_softirq at ffffffff8164845c #24 [] do_softirq at ffffffff81016fc5 #25 [] irq_exit at ffffffff81084ee5 #26 [] do_IRQ at ffffffff81648ff8 Of course it may happen with other NIC drivers as well. It's found the freed dst_entry here: 224 static bool tcp_in_quickack_mode(struct sock *sk)↩ 225 {↩ 226 ▹ const struct inet_connection_sock *icsk = inet_csk(sk);↩ 227 ▹ const struct dst_entry *dst = __sk_dst_get(sk);↩ 228 ↩ 229 ▹ return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩ 230 ▹ ▹ (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩ 231 }↩ But there are other backtraces attributed to the same freed dst_entry in netfilter code as well. All the vmcores showed 2 significant clues: - Remote hosts behind the default gateway had always been redirected to a different gateway. A rtable/dst_entry will be added for that host. Making more dst_entrys with lower reference counts. Making this more probable. - All vmcores showed a postitive LockDroppedIcmps value, e.g: LockDroppedIcmps 267 A closer look at the tcp_v4_err() handler revealed that do_redirect() will run regardless of whether user space has the socket locked. This can result in a race condition where the same dst_entry cached in sk->sk_dst_entry can be decremented twice for the same socket via: do_redirect()->__sk_dst_check()-> dst_release(). Which leads to the dst_entry being prematurely freed with another socket pointing to it via sk->sk_dst_cache and a subsequent crash. To fix this skip do_redirect() if usespace has the socket locked. Instead let the redirect take place later when user space does not have the socket locked. The dccp/IPv6 code is very similar in this respect, so fixing it there too. As Eric Garver pointed out the following commit now invalidates routes. Which can set the dst->obsolete flag so that ipv4_dst_check() returns null and triggers the dst_release(). Fixes: ceb3320610d6 ("ipv4: Kill routes during PMTU/redirect updates.") Cc: Eric Garver Cc: Hannes Sowa Signed-off-by: Jon Maxwell Signed-off-by: David S. Miller

net/dccp: fix use after free in tw_timer_handler()

2017-02-22T21:14:07Z

DCCP doesn't purge timewait sockets on network namespace shutdown. So, after net namespace destroyed we could still have an active timer which will trigger use after free in tw_timer_handler(): BUG: KASAN: use-after-free in tw_timer_handler+0x4a/0xa0 at addr ffff88010e0d1e10 Read of size 8 by task swapper/1/0 Call Trace: __asan_load8+0x54/0x90 tw_timer_handler+0x4a/0xa0 call_timer_fn+0x127/0x480 expire_timers+0x1db/0x2e0 run_timer_softirq+0x12f/0x2a0 __do_softirq+0x105/0x5b4 irq_exit+0xdd/0xf0 smp_apic_timer_interrupt+0x57/0x70 apic_timer_interrupt+0x90/0xa0 Object at ffff88010e0d1bc0, in cache net_namespace size: 6848 Allocated: save_stack_trace+0x1b/0x20 kasan_kmalloc+0xee/0x180 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc+0x134/0x310 copy_net_ns+0x8d/0x280 create_new_namespaces+0x23f/0x340 unshare_nsproxy_namespaces+0x75/0xf0 SyS_unshare+0x299/0x4f0 entry_SYSCALL_64_fastpath+0x18/0xad Freed: save_stack_trace+0x1b/0x20 kasan_slab_free+0xae/0x180 kmem_cache_free+0xb4/0x350 net_drop_ns+0x3f/0x50 cleanup_net+0x3df/0x450 process_one_work+0x419/0xbb0 worker_thread+0x92/0x850 kthread+0x192/0x1e0 ret_from_fork+0x2e/0x40 Add .exit_batch hook to dccp_v4_ops()/dccp_v6_ops() which will purge timewait sockets on net namespace destruction and prevent above issue. Fixes: f2bf415cfed7 ("mib: add net to NET_ADD_STATS_BH") Reported-by: Dmitry Vyukov Signed-off-by: Andrey Ryabinin Acked-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller

inet: drop ->bind_conflict

2017-01-18T18:04:28Z

The only difference between inet6_csk_bind_conflict and inet_csk_bind_conflict is how they check the rcv_saddr, so delete this call back and simply change inet_csk_bind_conflict to call inet_rcv_saddr_equal. Signed-off-by: Josef Bacik Signed-off-by: David S. Miller

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

2016-12-03T17:29:53Z

Couple conflicts resolved here: 1) In the MACB driver, a bug fix to properly initialize the RX tail pointer properly overlapped with some changes to support variable sized rings. 2) In XGBE we had a "CONFIG_PM" --> "CONFIG_PM_SLEEP" fix overlapping with a reorganization of the driver to support ACPI, OF, as well as PCI variants of the chip. 3) In 'net' we had several probe error path bug fixes to the stmmac driver, meanwhile a lot of this code was cleaned up and reorganized in 'net-next'. 4) The cls_flower classifier obtained a helper function in 'net-next' called __fl_delete() and this overlapped with Daniel Borkamann's bug fix to use RCU for object destruction in 'net'. It also overlapped with Jiri's change to guard the rhashtable_remove_fast() call with a check against tc_skip_sw(). 5) In mlx4, a revert bug fix in 'net' overlapped with some unrelated changes in 'net-next'. 6) In geneve, a stale header pointer after pskb_expand_head() bug fix in 'net' overlapped with a large reorganization of the same code in 'net-next'. Since the 'net-next' code no longer had the bug in question, there was nothing to do other than to simply take the 'net-next' hunks. Signed-off-by: David S. Miller

net/dccp: fix use-after-free in dccp_invalid_packet

2016-11-30T01:37:26Z

pskb_may_pull() can reallocate skb->head, we need to reload dh pointer in dccp_invalid_packet() or risk use after free. Bug found by Andrey Konovalov using syzkaller. Signed-off-by: Eric Dumazet Reported-by: Andrey Konovalov Signed-off-by: David S. Miller

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

2016-11-15T15:54:36Z

Several cases of bug fixes in 'net' overlapping other changes in 'net-next-. Signed-off-by: David S. Miller

dccp: fix out of bound access in dccp_v4_err()

2016-11-03T20:16:51Z

dccp_v4_err() does not use pskb_may_pull() and might access garbage. We only need 4 bytes at the beginning of the DCCP header, like TCP, so the 8 bytes pulled in icmp_socket_deliver() are more than enough. This patch might allow to process more ICMP messages, as some routers are still limiting the size of reflected bytes to 28 (RFC 792), instead of extended lengths (RFC 1812 4.3.2.3) Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller