linux-stable.git/net/ipv4, branch v3.14.13 Linux kernel stable tree udp: ipv4: do not waste time in __udp4_lib_mcast_demux_lookup 2014-06-26T19:15:40+00:00 Eric Dumazet edumazet@google.com 2014-06-12T23:13:06+00:00 724d0d32fa2a6242a0f03c1baeb8310e7ddcf9a9 [ Upstream commit 63c6f81cdde58c41da62a8d8a209592e42a0203e ] Its too easy to add thousand of UDP sockets on a particular bucket, and slow down an innocent multicast receiver. Early demux is supposed to be an optimization, we should avoid spending too much time in it. It is interesting to note __udp4_lib_demux_lookup() only tries to match first socket in the chain. 10 is the threshold we already have in __udp4_lib_lookup() to switch to secondary hash. Fixes: 421b3885bf6d5 ("udp: ipv4: Add udp early demux") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: David Held <drheld@google.com> Cc: Shawn Bohrer <sbohrer@rgmadvisors.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 63c6f81cdde58c41da62a8d8a209592e42a0203e ]

Its too easy to add thousand of UDP sockets on a particular bucket,
and slow down an innocent multicast receiver.

Early demux is supposed to be an optimization, we should avoid spending
too much time in it.

It is interesting to note __udp4_lib_demux_lookup() only tries to
match first socket in the chain.

10 is the threshold we already have in __udp4_lib_lookup() to switch
to secondary hash.

Fixes: 421b3885bf6d5 ("udp: ipv4: Add udp early demux")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: David Held <drheld@google.com>
Cc: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv4: fix a race in ip4_datagram_release_cb() 2014-06-26T19:15:40+00:00 Eric Dumazet edumazet@google.com 2014-06-10T13:43:01+00:00 3480c0154964f155afef8abceb1118debaf3d5b3 [ Upstream commit 9709674e68646cee5a24e3000b3558d25412203a ] Alexey gave a AddressSanitizer[1] report that finally gave a good hint at where was the origin of various problems already reported by Dormando in the past [2] Problem comes from the fact that UDP can have a lockless TX path, and concurrent threads can manipulate sk_dst_cache, while another thread, is holding socket lock and calls __sk_dst_set() in ip4_datagram_release_cb() (this was added in linux-3.8) It seems that all we need to do is to use sk_dst_check() and sk_dst_set() so that all the writers hold same spinlock (sk->sk_dst_lock) to prevent corruptions. TCP stack do not need this protection, as all sk_dst_cache writers hold the socket lock. [1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel AddressSanitizer: heap-use-after-free in ipv4_dst_check Read of size 2 by thread T15453: [<ffffffff817daa3a>] ipv4_dst_check+0x1a/0x90 ./net/ipv4/route.c:1116 [<ffffffff8175b789>] __sk_dst_check+0x89/0xe0 ./net/core/sock.c:531 [<ffffffff81830a36>] ip4_datagram_release_cb+0x46/0x390 ??:0 [<ffffffff8175eaea>] release_sock+0x17a/0x230 ./net/core/sock.c:2413 [<ffffffff81830882>] ip4_datagram_connect+0x462/0x5d0 ??:0 [<ffffffff81846d06>] inet_dgram_connect+0x76/0xd0 ./net/ipv4/af_inet.c:534 [<ffffffff817580ac>] SYSC_connect+0x15c/0x1c0 ./net/socket.c:1701 [<ffffffff817596ce>] SyS_connect+0xe/0x10 ./net/socket.c:1682 [<ffffffff818b0a29>] system_call_fastpath+0x16/0x1b ./arch/x86/kernel/entry_64.S:629 Freed by thread T15455: [<ffffffff8178d9b8>] dst_destroy+0xa8/0x160 ./net/core/dst.c:251 [<ffffffff8178de25>] dst_release+0x45/0x80 ./net/core/dst.c:280 [<ffffffff818304c1>] ip4_datagram_connect+0xa1/0x5d0 ??:0 [<ffffffff81846d06>] inet_dgram_connect+0x76/0xd0 ./net/ipv4/af_inet.c:534 [<ffffffff817580ac>] SYSC_connect+0x15c/0x1c0 ./net/socket.c:1701 [<ffffffff817596ce>] SyS_connect+0xe/0x10 ./net/socket.c:1682 [<ffffffff818b0a29>] system_call_fastpath+0x16/0x1b ./arch/x86/kernel/entry_64.S:629 Allocated by thread T15453: [<ffffffff8178d291>] dst_alloc+0x81/0x2b0 ./net/core/dst.c:171 [<ffffffff817db3b7>] rt_dst_alloc+0x47/0x50 ./net/ipv4/route.c:1406 [< inlined >] __ip_route_output_key+0x3e8/0xf70 __mkroute_output ./net/ipv4/route.c:1939 [<ffffffff817dde08>] __ip_route_output_key+0x3e8/0xf70 ./net/ipv4/route.c:2161 [<ffffffff817deb34>] ip_route_output_flow+0x14/0x30 ./net/ipv4/route.c:2249 [<ffffffff81830737>] ip4_datagram_connect+0x317/0x5d0 ??:0 [<ffffffff81846d06>] inet_dgram_connect+0x76/0xd0 ./net/ipv4/af_inet.c:534 [<ffffffff817580ac>] SYSC_connect+0x15c/0x1c0 ./net/socket.c:1701 [<ffffffff817596ce>] SyS_connect+0xe/0x10 ./net/socket.c:1682 [<ffffffff818b0a29>] system_call_fastpath+0x16/0x1b ./arch/x86/kernel/entry_64.S:629 [2] <4>[196727.311203] general protection fault: 0000 [#1] SMP <4>[196727.311224] Modules linked in: xt_TEE xt_dscp xt_DSCP macvlan bridge coretemp crc32_pclmul ghash_clmulni_intel gpio_ich microcode ipmi_watchdog ipmi_devintf sb_edac edac_core lpc_ich mfd_core tpm_tis tpm tpm_bios ipmi_si ipmi_msghandler isci igb libsas i2c_algo_bit ixgbe ptp pps_core mdio <4>[196727.311333] CPU: 17 PID: 0 Comm: swapper/17 Not tainted 3.10.26 #1 <4>[196727.311344] Hardware name: Supermicro X9DRi-LN4+/X9DR3-LN4+/X9DRi-LN4+/X9DR3-LN4+, BIOS 3.0 07/05/2013 <4>[196727.311364] task: ffff885e6f069700 ti: ffff885e6f072000 task.ti: ffff885e6f072000 <4>[196727.311377] RIP: 0010:[<ffffffff815f8c7f>] [<ffffffff815f8c7f>] ipv4_dst_destroy+0x4f/0x80 <4>[196727.311399] RSP: 0018:ffff885effd23a70 EFLAGS: 00010282 <4>[196727.311409] RAX: dead000000200200 RBX: ffff8854c398ecc0 RCX: 0000000000000040 <4>[196727.311423] RDX: dead000000100100 RSI: dead000000100100 RDI: dead000000200200 <4>[196727.311437] RBP: ffff885effd23a80 R08: ffffffff815fd9e0 R09: ffff885d5a590800 <4>[196727.311451] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 <4>[196727.311464] R13: ffffffff81c8c280 R14: 0000000000000000 R15: ffff880e85ee16ce <4>[196727.311510] FS: 0000000000000000(0000) GS:ffff885effd20000(0000) knlGS:0000000000000000 <4>[196727.311554] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 <4>[196727.311581] CR2: 00007a46751eb000 CR3: 0000005e65688000 CR4: 00000000000407e0 <4>[196727.311625] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 <4>[196727.311669] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 <4>[196727.311713] Stack: <4>[196727.311733] ffff8854c398ecc0 ffff8854c398ecc0 ffff885effd23ab0 ffffffff815b7f42 <4>[196727.311784] ffff88be6595bc00 ffff8854c398ecc0 0000000000000000 ffff8854c398ecc0 <4>[196727.311834] ffff885effd23ad0 ffffffff815b86c6 ffff885d5a590800 ffff8816827821c0 <4>[196727.311885] Call Trace: <4>[196727.311907] <IRQ> <4>[196727.311912] [<ffffffff815b7f42>] dst_destroy+0x32/0xe0 <4>[196727.311959] [<ffffffff815b86c6>] dst_release+0x56/0x80 <4>[196727.311986] [<ffffffff81620bd5>] tcp_v4_do_rcv+0x2a5/0x4a0 <4>[196727.312013] [<ffffffff81622b5a>] tcp_v4_rcv+0x7da/0x820 <4>[196727.312041] [<ffffffff815fd9e0>] ? ip_rcv_finish+0x360/0x360 <4>[196727.312070] [<ffffffff815de02d>] ? nf_hook_slow+0x7d/0x150 <4>[196727.312097] [<ffffffff815fd9e0>] ? ip_rcv_finish+0x360/0x360 <4>[196727.312125] [<ffffffff815fda92>] ip_local_deliver_finish+0xb2/0x230 <4>[196727.312154] [<ffffffff815fdd9a>] ip_local_deliver+0x4a/0x90 <4>[196727.312183] [<ffffffff815fd799>] ip_rcv_finish+0x119/0x360 <4>[196727.312212] [<ffffffff815fe00b>] ip_rcv+0x22b/0x340 <4>[196727.312242] [<ffffffffa0339680>] ? macvlan_broadcast+0x160/0x160 [macvlan] <4>[196727.312275] [<ffffffff815b0c62>] __netif_receive_skb_core+0x512/0x640 <4>[196727.312308] [<ffffffff811427fb>] ? kmem_cache_alloc+0x13b/0x150 <4>[196727.312338] [<ffffffff815b0db1>] __netif_receive_skb+0x21/0x70 <4>[196727.312368] [<ffffffff815b0fa1>] netif_receive_skb+0x31/0xa0 <4>[196727.312397] [<ffffffff815b1ae8>] napi_gro_receive+0xe8/0x140 <4>[196727.312433] [<ffffffffa00274f1>] ixgbe_poll+0x551/0x11f0 [ixgbe] <4>[196727.312463] [<ffffffff815fe00b>] ? ip_rcv+0x22b/0x340 <4>[196727.312491] [<ffffffff815b1691>] net_rx_action+0x111/0x210 <4>[196727.312521] [<ffffffff815b0db1>] ? __netif_receive_skb+0x21/0x70 <4>[196727.312552] [<ffffffff810519d0>] __do_softirq+0xd0/0x270 <4>[196727.312583] [<ffffffff816cef3c>] call_softirq+0x1c/0x30 <4>[196727.312613] [<ffffffff81004205>] do_softirq+0x55/0x90 <4>[196727.312640] [<ffffffff81051c85>] irq_exit+0x55/0x60 <4>[196727.312668] [<ffffffff816cf5c3>] do_IRQ+0x63/0xe0 <4>[196727.312696] [<ffffffff816c5aaa>] common_interrupt+0x6a/0x6a <4>[196727.312722] <EOI> <1>[196727.313071] RIP [<ffffffff815f8c7f>] ipv4_dst_destroy+0x4f/0x80 <4>[196727.313100] RSP <ffff885effd23a70> <4>[196727.313377] ---[ end trace 64b3f14fae0f2e29 ]--- <0>[196727.380908] Kernel panic - not syncing: Fatal exception in interrupt Reported-by: Alexey Preobrazhensky <preobr@google.com> Reported-by: dormando <dormando@rydia.ne> Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: 8141ed9fcedb2 ("ipv4: Add a socket release callback for datagram sockets") Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 9709674e68646cee5a24e3000b3558d25412203a ]

Alexey gave a AddressSanitizer[1] report that finally gave a good hint
at where was the origin of various problems already reported by Dormando
in the past [2]

Problem comes from the fact that UDP can have a lockless TX path, and
concurrent threads can manipulate sk_dst_cache, while another thread,
is holding socket lock and calls __sk_dst_set() in
ip4_datagram_release_cb() (this was added in linux-3.8)

It seems that all we need to do is to use sk_dst_check() and
sk_dst_set() so that all the writers hold same spinlock
(sk->sk_dst_lock) to prevent corruptions.

TCP stack do not need this protection, as all sk_dst_cache writers hold
the socket lock.

[1]
https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel

AddressSanitizer: heap-use-after-free in ipv4_dst_check
Read of size 2 by thread T15453:
 [<ffffffff817daa3a>] ipv4_dst_check+0x1a/0x90 ./net/ipv4/route.c:1116
 [<ffffffff8175b789>] __sk_dst_check+0x89/0xe0 ./net/core/sock.c:531
 [<ffffffff81830a36>] ip4_datagram_release_cb+0x46/0x390 ??:0
 [<ffffffff8175eaea>] release_sock+0x17a/0x230 ./net/core/sock.c:2413
 [<ffffffff81830882>] ip4_datagram_connect+0x462/0x5d0 ??:0
 [<ffffffff81846d06>] inet_dgram_connect+0x76/0xd0 ./net/ipv4/af_inet.c:534
 [<ffffffff817580ac>] SYSC_connect+0x15c/0x1c0 ./net/socket.c:1701
 [<ffffffff817596ce>] SyS_connect+0xe/0x10 ./net/socket.c:1682
 [<ffffffff818b0a29>] system_call_fastpath+0x16/0x1b
./arch/x86/kernel/entry_64.S:629

Freed by thread T15455:
 [<ffffffff8178d9b8>] dst_destroy+0xa8/0x160 ./net/core/dst.c:251
 [<ffffffff8178de25>] dst_release+0x45/0x80 ./net/core/dst.c:280
 [<ffffffff818304c1>] ip4_datagram_connect+0xa1/0x5d0 ??:0
 [<ffffffff81846d06>] inet_dgram_connect+0x76/0xd0 ./net/ipv4/af_inet.c:534
 [<ffffffff817580ac>] SYSC_connect+0x15c/0x1c0 ./net/socket.c:1701
 [<ffffffff817596ce>] SyS_connect+0xe/0x10 ./net/socket.c:1682
 [<ffffffff818b0a29>] system_call_fastpath+0x16/0x1b
./arch/x86/kernel/entry_64.S:629

Allocated by thread T15453:
 [<ffffffff8178d291>] dst_alloc+0x81/0x2b0 ./net/core/dst.c:171
 [<ffffffff817db3b7>] rt_dst_alloc+0x47/0x50 ./net/ipv4/route.c:1406
 [<     inlined    >] __ip_route_output_key+0x3e8/0xf70
__mkroute_output ./net/ipv4/route.c:1939
 [<ffffffff817dde08>] __ip_route_output_key+0x3e8/0xf70 ./net/ipv4/route.c:2161
 [<ffffffff817deb34>] ip_route_output_flow+0x14/0x30 ./net/ipv4/route.c:2249
 [<ffffffff81830737>] ip4_datagram_connect+0x317/0x5d0 ??:0
 [<ffffffff81846d06>] inet_dgram_connect+0x76/0xd0 ./net/ipv4/af_inet.c:534
 [<ffffffff817580ac>] SYSC_connect+0x15c/0x1c0 ./net/socket.c:1701
 [<ffffffff817596ce>] SyS_connect+0xe/0x10 ./net/socket.c:1682
 [<ffffffff818b0a29>] system_call_fastpath+0x16/0x1b
./arch/x86/kernel/entry_64.S:629

[2]
<4>[196727.311203] general protection fault: 0000 [#1] SMP
<4>[196727.311224] Modules linked in: xt_TEE xt_dscp xt_DSCP macvlan bridge coretemp crc32_pclmul ghash_clmulni_intel gpio_ich microcode ipmi_watchdog ipmi_devintf sb_edac edac_core lpc_ich mfd_core tpm_tis tpm tpm_bios ipmi_si ipmi_msghandler isci igb libsas i2c_algo_bit ixgbe ptp pps_core mdio
<4>[196727.311333] CPU: 17 PID: 0 Comm: swapper/17 Not tainted 3.10.26 #1
<4>[196727.311344] Hardware name: Supermicro X9DRi-LN4+/X9DR3-LN4+/X9DRi-LN4+/X9DR3-LN4+, BIOS 3.0 07/05/2013
<4>[196727.311364] task: ffff885e6f069700 ti: ffff885e6f072000 task.ti: ffff885e6f072000
<4>[196727.311377] RIP: 0010:[<ffffffff815f8c7f>]  [<ffffffff815f8c7f>] ipv4_dst_destroy+0x4f/0x80
<4>[196727.311399] RSP: 0018:ffff885effd23a70  EFLAGS: 00010282
<4>[196727.311409] RAX: dead000000200200 RBX: ffff8854c398ecc0 RCX: 0000000000000040
<4>[196727.311423] RDX: dead000000100100 RSI: dead000000100100 RDI: dead000000200200
<4>[196727.311437] RBP: ffff885effd23a80 R08: ffffffff815fd9e0 R09: ffff885d5a590800
<4>[196727.311451] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
<4>[196727.311464] R13: ffffffff81c8c280 R14: 0000000000000000 R15: ffff880e85ee16ce
<4>[196727.311510] FS:  0000000000000000(0000) GS:ffff885effd20000(0000) knlGS:0000000000000000
<4>[196727.311554] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[196727.311581] CR2: 00007a46751eb000 CR3: 0000005e65688000 CR4: 00000000000407e0
<4>[196727.311625] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
<4>[196727.311669] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
<4>[196727.311713] Stack:
<4>[196727.311733]  ffff8854c398ecc0 ffff8854c398ecc0 ffff885effd23ab0 ffffffff815b7f42
<4>[196727.311784]  ffff88be6595bc00 ffff8854c398ecc0 0000000000000000 ffff8854c398ecc0
<4>[196727.311834]  ffff885effd23ad0 ffffffff815b86c6 ffff885d5a590800 ffff8816827821c0
<4>[196727.311885] Call Trace:
<4>[196727.311907]  <IRQ>
<4>[196727.311912]  [<ffffffff815b7f42>] dst_destroy+0x32/0xe0
<4>[196727.311959]  [<ffffffff815b86c6>] dst_release+0x56/0x80
<4>[196727.311986]  [<ffffffff81620bd5>] tcp_v4_do_rcv+0x2a5/0x4a0
<4>[196727.312013]  [<ffffffff81622b5a>] tcp_v4_rcv+0x7da/0x820
<4>[196727.312041]  [<ffffffff815fd9e0>] ? ip_rcv_finish+0x360/0x360
<4>[196727.312070]  [<ffffffff815de02d>] ? nf_hook_slow+0x7d/0x150
<4>[196727.312097]  [<ffffffff815fd9e0>] ? ip_rcv_finish+0x360/0x360
<4>[196727.312125]  [<ffffffff815fda92>] ip_local_deliver_finish+0xb2/0x230
<4>[196727.312154]  [<ffffffff815fdd9a>] ip_local_deliver+0x4a/0x90
<4>[196727.312183]  [<ffffffff815fd799>] ip_rcv_finish+0x119/0x360
<4>[196727.312212]  [<ffffffff815fe00b>] ip_rcv+0x22b/0x340
<4>[196727.312242]  [<ffffffffa0339680>] ? macvlan_broadcast+0x160/0x160 [macvlan]
<4>[196727.312275]  [<ffffffff815b0c62>] __netif_receive_skb_core+0x512/0x640
<4>[196727.312308]  [<ffffffff811427fb>] ? kmem_cache_alloc+0x13b/0x150
<4>[196727.312338]  [<ffffffff815b0db1>] __netif_receive_skb+0x21/0x70
<4>[196727.312368]  [<ffffffff815b0fa1>] netif_receive_skb+0x31/0xa0
<4>[196727.312397]  [<ffffffff815b1ae8>] napi_gro_receive+0xe8/0x140
<4>[196727.312433]  [<ffffffffa00274f1>] ixgbe_poll+0x551/0x11f0 [ixgbe]
<4>[196727.312463]  [<ffffffff815fe00b>] ? ip_rcv+0x22b/0x340
<4>[196727.312491]  [<ffffffff815b1691>] net_rx_action+0x111/0x210
<4>[196727.312521]  [<ffffffff815b0db1>] ? __netif_receive_skb+0x21/0x70
<4>[196727.312552]  [<ffffffff810519d0>] __do_softirq+0xd0/0x270
<4>[196727.312583]  [<ffffffff816cef3c>] call_softirq+0x1c/0x30
<4>[196727.312613]  [<ffffffff81004205>] do_softirq+0x55/0x90
<4>[196727.312640]  [<ffffffff81051c85>] irq_exit+0x55/0x60
<4>[196727.312668]  [<ffffffff816cf5c3>] do_IRQ+0x63/0xe0
<4>[196727.312696]  [<ffffffff816c5aaa>] common_interrupt+0x6a/0x6a
<4>[196727.312722]  <EOI>
<1>[196727.313071] RIP  [<ffffffff815f8c7f>] ipv4_dst_destroy+0x4f/0x80
<4>[196727.313100]  RSP <ffff885effd23a70>
<4>[196727.313377] ---[ end trace 64b3f14fae0f2e29 ]---
<0>[196727.380908] Kernel panic - not syncing: Fatal exception in interrupt

Reported-by: Alexey Preobrazhensky <preobr@google.com>
Reported-by: dormando <dormando@rydia.ne>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 8141ed9fcedb2 ("ipv4: Add a socket release callback for datagram sockets")
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipip, sit: fix ipv4_{update_pmtu,redirect} calls 2014-06-26T19:15:40+00:00 Dmitry Popov ixaphire@qrator.net 2014-06-06T19:19:21+00:00 a7b791bc2b6fcc29f7c56a375823d436f7f233ce [ Upstream commit 2346829e641b804ece9ac9298136b56d9567c278 ] ipv4_{update_pmtu,redirect} were called with tunnel's ifindex (t->dev is a tunnel netdevice). It caused wrong route lookup and failure of pmtu update or redirect. We should use the same ifindex that we use in ip_route_output_* in *tunnel_xmit code. It is t->parms.link . Signed-off-by: Dmitry Popov <ixaphire@qrator.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 2346829e641b804ece9ac9298136b56d9567c278 ]

ipv4_{update_pmtu,redirect} were called with tunnel's ifindex (t->dev is a
tunnel netdevice). It caused wrong route lookup and failure of pmtu update or
redirect. We should use the same ifindex that we use in ip_route_output_* in
*tunnel_xmit code. It is t->parms.link .

Signed-off-by: Dmitry Popov <ixaphire@qrator.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp: fix cwnd undo on DSACK in F-RTO 2014-06-26T19:15:39+00:00 Yuchung Cheng ycheng@google.com 2014-05-30T22:25:59+00:00 d86b9e396a82cf7988a9ba3b9943f47f146ad770 [ Upstream commit 0cfa5c07d6d1d7f8e710fc671c5ba1ce85e09fa4 ] This bug is discovered by an recent F-RTO issue on tcpm list https://www.ietf.org/mail-archive/web/tcpm/current/msg08794.html The bug is that currently F-RTO does not use DSACK to undo cwnd in certain cases: upon receiving an ACK after the RTO retransmission in F-RTO, and the ACK has DSACK indicating the retransmission is spurious, the sender only calls tcp_try_undo_loss() if some never retransmisted data is sacked (FLAG_ORIG_DATA_SACKED). The correct behavior is to unconditionally call tcp_try_undo_loss so the DSACK information is used properly to undo the cwnd reduction. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 0cfa5c07d6d1d7f8e710fc671c5ba1ce85e09fa4 ]

This bug is discovered by an recent F-RTO issue on tcpm list
https://www.ietf.org/mail-archive/web/tcpm/current/msg08794.html

The bug is that currently F-RTO does not use DSACK to undo cwnd in
certain cases: upon receiving an ACK after the RTO retransmission in
F-RTO, and the ACK has DSACK indicating the retransmission is spurious,
the sender only calls tcp_try_undo_loss() if some never retransmisted
data is sacked (FLAG_ORIG_DATA_SACKED).

The correct behavior is to unconditionally call tcp_try_undo_loss so
the DSACK information is used properly to undo the cwnd reduction.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: tunnels - enable module autoloading 2014-06-26T19:15:39+00:00 Tom Gundersen teg@jklm.no 2014-05-15T21:21:30+00:00 54b3bda49c9888d8e1655bf8c7b73c5d15fda34c [ Upstream commit f98f89a0104454f35a62d681683c844f6dbf4043 ] Enable the module alias hookup to allow tunnel modules to be autoloaded on demand. This is in line with how most other netdev kinds work, and will allow userspace to create tunnels without having CAP_SYS_MODULE. Signed-off-by: Tom Gundersen <teg@jklm.no> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit f98f89a0104454f35a62d681683c844f6dbf4043 ]

Enable the module alias hookup to allow tunnel modules to be autoloaded on demand.

This is in line with how most other netdev kinds work, and will allow userspace
to create tunnels without having CAP_SYS_MODULE.

Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: ipv4: defrag: set local_df flag on defragmented skb 2014-06-16T20:40:32+00:00 Florian Westphal fw@strlen.de 2014-05-02T13:32:16+00:00 806d009907bd86a03ecc7889e5794db74ba24ba6 commit 895162b1101b3ea5db08ca6822ae9672717efec0 upstream. else we may fail to forward skb even if original fragments do fit outgoing link mtu: 1. remote sends 2k packets in two 1000 byte frags, DF set 2. we want to forward but only see '2k > mtu and DF set' 3. we then send icmp error saying that outgoing link is 1500 But original sender never sent a packet that would not fit the outgoing link. Setting local_df makes outgoing path test size vs. IPCB(skb)->frag_max_size, so we will still send the correct error in case the largest original size did not fit outgoing link mtu. Reported-by: Maxime Bizon <mbizon@freebox.fr> Suggested-by: Maxime Bizon <mbizon@freebox.fr> Fixes: 5f2d04f1f9 (ipv4: fix path MTU discovery with connection tracking) Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 895162b1101b3ea5db08ca6822ae9672717efec0 upstream.

else we may fail to forward skb even if original fragments do fit
outgoing link mtu:

1. remote sends 2k packets in two 1000 byte frags, DF set
2. we want to forward but only see '2k > mtu and DF set'
3. we then send icmp error saying that outgoing link is 1500

But original sender never sent a packet that would not fit
the outgoing link.

Setting local_df makes outgoing path test size vs.
IPCB(skb)->frag_max_size, so we will still send the correct
error in case the largest original size did not fit
outgoing link mtu.

Reported-by: Maxime Bizon <mbizon@freebox.fr>
Suggested-by: Maxime Bizon <mbizon@freebox.fr>
Fixes: 5f2d04f1f9 (ipv4: fix path MTU discovery with connection tracking)
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv4: initialise the itag variable in __mkroute_input 2014-05-31T20:20:39+00:00 Li RongQing roy.qing.li@gmail.com 2014-05-22T08:36:55+00:00 242339a25ed829432d99e6571d170b308432ed55 [ Upstream commit fbdc0ad095c0a299e9abf5d8ac8f58374951149a ] the value of itag is a random value from stack, and may not be initiated by fib_validate_source, which called fib_combine_itag if CONFIG_IP_ROUTE_CLASSID is not set This will make the cached dst uncertainty Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit fbdc0ad095c0a299e9abf5d8ac8f58374951149a ]

the value of itag is a random value from stack, and may not be initiated by
fib_validate_source, which called fib_combine_itag if CONFIG_IP_ROUTE_CLASSID
is not set

This will make the cached dst uncertainty

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip_tunnel: Initialize the fallback device properly 2014-05-31T20:20:39+00:00 Steffen Klassert steffen.klassert@secunet.com 2014-05-19T09:36:56+00:00 49da0655e28b5bf9d869e1c50c15c990c5db5f94 [ Upstream commit 78ff4be45a4c51d8fb21ad92e4fabb467c6c3eeb ] We need to initialize the fallback device to have a correct mtu set on this device. Otherwise the mtu is set to null and the device is unusable. Fixes: fd58156e456d ("IPIP: Use ip-tunneling code.") Cc: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 78ff4be45a4c51d8fb21ad92e4fabb467c6c3eeb ]

We need to initialize the fallback device to have a correct mtu
set on this device. Otherwise the mtu is set to null and the device
is unusable.

Fixes: fd58156e456d ("IPIP: Use ip-tunneling code.")
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv4: fib_semantics: increment fib_info_cnt after fib_info allocation 2014-05-31T20:20:37+00:00 Sergey Popovich popovich_sergei@mail.ru 2014-05-06T15:23:08+00:00 13c5c91b6b4a68dd9ac5b4ea9974c0d1402daa0f [ Upstream commit aeefa1ecfc799b0ea2c4979617f14cecd5cccbfd ] Increment fib_info_cnt in fib_create_info() right after successfuly alllocating fib_info structure, overwise fib_metrics allocation failure leads to fib_info_cnt incorrectly decremented in free_fib_info(), called on error path from fib_create_info(). Signed-off-by: Sergey Popovich <popovich_sergei@mail.ru> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit aeefa1ecfc799b0ea2c4979617f14cecd5cccbfd ]

Increment fib_info_cnt in fib_create_info() right after successfuly
alllocating fib_info structure, overwise fib_metrics allocation failure
leads to fib_info_cnt incorrectly decremented in free_fib_info(), called
on error path from fib_create_info().

Signed-off-by: Sergey Popovich <popovich_sergei@mail.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: ipv4: ip_forward: fix inverted local_df test 2014-05-31T20:20:37+00:00 Florian Westphal fw@strlen.de 2014-05-04T21:24:31+00:00 1f68835d92bbfe3a14d369d3dce123c94521b105 [ Upstream commit ca6c5d4ad216d5942ae544bbf02503041bd802aa ] local_df means 'ignore DF bit if set', so if its set we're allowed to perform ip fragmentation. This wasn't noticed earlier because the output path also drops such skbs (and emits needed icmp error) and because netfilter ip defrag did not set local_df until couple of days ago. Only difference is that DF-packets-larger-than MTU now discarded earlier (f.e. we avoid pointless netfilter postrouting trip). While at it, drop the repeated test ip_exceeds_mtu, checking it once is enough... Fixes: fe6cc55f3a9 ("net: ip, ipv6: handle gso skbs in forwarding path") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit ca6c5d4ad216d5942ae544bbf02503041bd802aa ]

local_df means 'ignore DF bit if set', so if its set we're
allowed to perform ip fragmentation.

This wasn't noticed earlier because the output path also drops such skbs
(and emits needed icmp error) and because netfilter ip defrag did not
set local_df until couple of days ago.

Only difference is that DF-packets-larger-than MTU now discarded
earlier (f.e. we avoid pointless netfilter postrouting trip).

While at it, drop the repeated test ip_exceeds_mtu, checking it once
is enough...

Fixes: fe6cc55f3a9 ("net: ip, ipv6: handle gso skbs in forwarding path")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>