<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include/net, branch v4.9.64</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>netfilter: nat: Revert "netfilter: nat: convert nat bysrc hash to rhashtable"</title>
<updated>2017-11-18T10:22:24+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2017-09-06T12:39:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a23349bb9f1283e6262c096e7b805168772dd8ca'/>
<id>a23349bb9f1283e6262c096e7b805168772dd8ca</id>
<content type='text'>
commit e1bf1687740ce1a3598a1c5e452b852ff2190682 upstream.

This reverts commit 870190a9ec9075205c0fa795a09fa931694a3ff1.

It was not a good idea. The custom hash table was a much better
fit for this purpose.

A fast lookup is not essential, in fact for most cases there is no lookup
at all because original tuple is not taken and can be used as-is.
What needs to be fast is insertion and deletion.

rhlist removal however requires a rhlist walk.
We can have thousands of entries in such a list if source port/addresses
are reused for multiple flows, if this happens removal requests are so
expensive that deletions of a few thousand flows can take several
seconds(!).

The advantages that we got from rhashtable are:
1) table auto-sizing
2) multiple locks

1) would be nice to have, but it is not essential as we have at
most one lookup per new flow, so even a million flows in the bysource
table are not a problem compared to current deletion cost.
2) is easy to add to custom hash table.

I tried to add hlist_node to rhlist to speed up rhltable_remove but this
isn't doable without changing semantics.  rhltable_remove_fast will
check that the to-be-deleted object is part of the table and that
requires a list walk that we want to avoid.

Furthermore, using hlist_node increases size of struct rhlist_head, which
in turn increases nf_conn size.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=196821
Reported-by: Ivan Babrou &lt;ibobrik@gmail.com&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit e1bf1687740ce1a3598a1c5e452b852ff2190682 upstream.

This reverts commit 870190a9ec9075205c0fa795a09fa931694a3ff1.

It was not a good idea. The custom hash table was a much better
fit for this purpose.

A fast lookup is not essential, in fact for most cases there is no lookup
at all because original tuple is not taken and can be used as-is.
What needs to be fast is insertion and deletion.

rhlist removal however requires a rhlist walk.
We can have thousands of entries in such a list if source port/addresses
are reused for multiple flows, if this happens removal requests are so
expensive that deletions of a few thousand flows can take several
seconds(!).

The advantages that we got from rhashtable are:
1) table auto-sizing
2) multiple locks

1) would be nice to have, but it is not essential as we have at
most one lookup per new flow, so even a million flows in the bysource
table are not a problem compared to current deletion cost.
2) is easy to add to custom hash table.

I tried to add hlist_node to rhlist to speed up rhltable_remove but this
isn't doable without changing semantics.  rhltable_remove_fast will
check that the to-be-deleted object is part of the table and that
requires a list walk that we want to avoid.

Furthermore, using hlist_node increases size of struct rhlist_head, which
in turn increases nf_conn size.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=196821
Reported-by: Ivan Babrou &lt;ibobrik@gmail.com&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>tcp/dccp: fix other lockdep splats accessing ireq_opt</title>
<updated>2017-11-18T10:22:22+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2017-10-24T15:20:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2af59c6557a5f5e18b5552fe8526033b032978d5'/>
<id>2af59c6557a5f5e18b5552fe8526033b032978d5</id>
<content type='text'>
[ Upstream commit 06f877d613be3621604c2520ec0351d9fbdca15f ]

In my first attempt to fix the lockdep splat, I forgot we could
enter inet_csk_route_req() with a freshly allocated request socket,
for which refcount has not yet been elevated, due to complex
SLAB_TYPESAFE_BY_RCU rules.

We either are in rcu_read_lock() section _or_ we own a refcount on the
request.

Correct RCU verb to use here is rcu_dereference_check(), although it is
not possible to prove we actually own a reference on a shared
refcount :/

In v2, I added ireq_opt_deref() helper and use in three places, to fix other
possible splats.

[   49.844590]  lockdep_rcu_suspicious+0xea/0xf3
[   49.846487]  inet_csk_route_req+0x53/0x14d
[   49.848334]  tcp_v4_route_req+0xe/0x10
[   49.850174]  tcp_conn_request+0x31c/0x6a0
[   49.851992]  ? __lock_acquire+0x614/0x822
[   49.854015]  tcp_v4_conn_request+0x5a/0x79
[   49.855957]  ? tcp_v4_conn_request+0x5a/0x79
[   49.858052]  tcp_rcv_state_process+0x98/0xdcc
[   49.859990]  ? sk_filter_trim_cap+0x2f6/0x307
[   49.862085]  tcp_v4_do_rcv+0xfc/0x145
[   49.864055]  ? tcp_v4_do_rcv+0xfc/0x145
[   49.866173]  tcp_v4_rcv+0x5ab/0xaf9
[   49.868029]  ip_local_deliver_finish+0x1af/0x2e7
[   49.870064]  ip_local_deliver+0x1b2/0x1c5
[   49.871775]  ? inet_del_offload+0x45/0x45
[   49.873916]  ip_rcv_finish+0x3f7/0x471
[   49.875476]  ip_rcv+0x3f1/0x42f
[   49.876991]  ? ip_local_deliver_finish+0x2e7/0x2e7
[   49.878791]  __netif_receive_skb_core+0x6d3/0x950
[   49.880701]  ? process_backlog+0x7e/0x216
[   49.882589]  __netif_receive_skb+0x1d/0x5e
[   49.884122]  process_backlog+0x10c/0x216
[   49.885812]  net_rx_action+0x147/0x3df

Fixes: a6ca7abe53633 ("tcp/dccp: fix lockdep splat in inet_csk_route_req()")
Fixes: c92e8c02fe66 ("tcp/dccp: fix ireq-&gt;opt races")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: kernel test robot &lt;fengguang.wu@intel.com&gt;
Reported-by: Maciej Żenczykowski &lt;maze@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 06f877d613be3621604c2520ec0351d9fbdca15f ]

In my first attempt to fix the lockdep splat, I forgot we could
enter inet_csk_route_req() with a freshly allocated request socket,
for which refcount has not yet been elevated, due to complex
SLAB_TYPESAFE_BY_RCU rules.

We either are in rcu_read_lock() section _or_ we own a refcount on the
request.

Correct RCU verb to use here is rcu_dereference_check(), although it is
not possible to prove we actually own a reference on a shared
refcount :/

In v2, I added ireq_opt_deref() helper and use in three places, to fix other
possible splats.

[   49.844590]  lockdep_rcu_suspicious+0xea/0xf3
[   49.846487]  inet_csk_route_req+0x53/0x14d
[   49.848334]  tcp_v4_route_req+0xe/0x10
[   49.850174]  tcp_conn_request+0x31c/0x6a0
[   49.851992]  ? __lock_acquire+0x614/0x822
[   49.854015]  tcp_v4_conn_request+0x5a/0x79
[   49.855957]  ? tcp_v4_conn_request+0x5a/0x79
[   49.858052]  tcp_rcv_state_process+0x98/0xdcc
[   49.859990]  ? sk_filter_trim_cap+0x2f6/0x307
[   49.862085]  tcp_v4_do_rcv+0xfc/0x145
[   49.864055]  ? tcp_v4_do_rcv+0xfc/0x145
[   49.866173]  tcp_v4_rcv+0x5ab/0xaf9
[   49.868029]  ip_local_deliver_finish+0x1af/0x2e7
[   49.870064]  ip_local_deliver+0x1b2/0x1c5
[   49.871775]  ? inet_del_offload+0x45/0x45
[   49.873916]  ip_rcv_finish+0x3f7/0x471
[   49.875476]  ip_rcv+0x3f1/0x42f
[   49.876991]  ? ip_local_deliver_finish+0x2e7/0x2e7
[   49.878791]  __netif_receive_skb_core+0x6d3/0x950
[   49.880701]  ? process_backlog+0x7e/0x216
[   49.882589]  __netif_receive_skb+0x1d/0x5e
[   49.884122]  process_backlog+0x10c/0x216
[   49.885812]  net_rx_action+0x147/0x3df

Fixes: a6ca7abe53633 ("tcp/dccp: fix lockdep splat in inet_csk_route_req()")
Fixes: c92e8c02fe66 ("tcp/dccp: fix ireq-&gt;opt races")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: kernel test robot &lt;fengguang.wu@intel.com&gt;
Reported-by: Maciej Żenczykowski &lt;maze@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp/dccp: fix ireq-&gt;opt races</title>
<updated>2017-11-18T10:22:22+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2017-10-20T16:04:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2ffd261337246d9a2992ca5083882790869f8986'/>
<id>2ffd261337246d9a2992ca5083882790869f8986</id>
<content type='text'>
[ Upstream commit c92e8c02fe664155ac4234516e32544bec0f113d ]

syzkaller found another bug in DCCP/TCP stacks [1]

For the reasons explained in commit ce1050089c96 ("tcp/dccp: fix
ireq-&gt;pktopts race"), we need to make sure we do not access
ireq-&gt;opt unless we own the request sock.

Note the opt field is renamed to ireq_opt to ease grep games.

[1]
BUG: KASAN: use-after-free in ip_queue_xmit+0x1687/0x18e0 net/ipv4/ip_output.c:474
Read of size 1 at addr ffff8801c951039c by task syz-executor5/3295

CPU: 1 PID: 3295 Comm: syz-executor5 Not tainted 4.14.0-rc4+ #80
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
 ip_queue_xmit+0x1687/0x18e0 net/ipv4/ip_output.c:474
 tcp_transmit_skb+0x1ab7/0x3840 net/ipv4/tcp_output.c:1135
 tcp_send_ack.part.37+0x3bb/0x650 net/ipv4/tcp_output.c:3587
 tcp_send_ack+0x49/0x60 net/ipv4/tcp_output.c:3557
 __tcp_ack_snd_check+0x2c6/0x4b0 net/ipv4/tcp_input.c:5072
 tcp_ack_snd_check net/ipv4/tcp_input.c:5085 [inline]
 tcp_rcv_state_process+0x2eff/0x4850 net/ipv4/tcp_input.c:6071
 tcp_child_process+0x342/0x990 net/ipv4/tcp_minisocks.c:816
 tcp_v4_rcv+0x1827/0x2f80 net/ipv4/tcp_ipv4.c:1682
 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:464 [inline]
 ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
 netif_receive_skb+0xae/0x390 net/core/dev.c:4611
 tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
 tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
 call_write_iter include/linux/fs.h:1770 [inline]
 new_sync_write fs/read_write.c:468 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:481
 vfs_write+0x18f/0x510 fs/read_write.c:543
 SYSC_write fs/read_write.c:588 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:580
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x40c341
RSP: 002b:00007f469523ec10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 000000000040c341
RDX: 0000000000000037 RSI: 0000000020004000 RDI: 0000000000000015
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000f4240 R11: 0000000000000293 R12: 00000000004b7fd1
R13: 00000000ffffffff R14: 0000000020000000 R15: 0000000000025000

Allocated by task 3295:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3725 [inline]
 __kmalloc+0x162/0x760 mm/slab.c:3734
 kmalloc include/linux/slab.h:498 [inline]
 tcp_v4_save_options include/net/tcp.h:1962 [inline]
 tcp_v4_init_req+0x2d3/0x3e0 net/ipv4/tcp_ipv4.c:1271
 tcp_conn_request+0xf6d/0x3410 net/ipv4/tcp_input.c:6283
 tcp_v4_conn_request+0x157/0x210 net/ipv4/tcp_ipv4.c:1313
 tcp_rcv_state_process+0x8ea/0x4850 net/ipv4/tcp_input.c:5857
 tcp_v4_do_rcv+0x55c/0x7d0 net/ipv4/tcp_ipv4.c:1482
 tcp_v4_rcv+0x2d10/0x2f80 net/ipv4/tcp_ipv4.c:1711
 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:464 [inline]
 ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
 netif_receive_skb+0xae/0x390 net/core/dev.c:4611
 tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
 tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
 call_write_iter include/linux/fs.h:1770 [inline]
 new_sync_write fs/read_write.c:468 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:481
 vfs_write+0x18f/0x510 fs/read_write.c:543
 SYSC_write fs/read_write.c:588 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:580
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 3306:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xca/0x250 mm/slab.c:3820
 inet_sock_destruct+0x59d/0x950 net/ipv4/af_inet.c:157
 __sk_destruct+0xfd/0x910 net/core/sock.c:1560
 sk_destruct+0x47/0x80 net/core/sock.c:1595
 __sk_free+0x57/0x230 net/core/sock.c:1603
 sk_free+0x2a/0x40 net/core/sock.c:1614
 sock_put include/net/sock.h:1652 [inline]
 inet_csk_complete_hashdance+0xd5/0xf0 net/ipv4/inet_connection_sock.c:959
 tcp_check_req+0xf4d/0x1620 net/ipv4/tcp_minisocks.c:765
 tcp_v4_rcv+0x17f6/0x2f80 net/ipv4/tcp_ipv4.c:1675
 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:464 [inline]
 ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
 netif_receive_skb+0xae/0x390 net/core/dev.c:4611
 tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
 tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
 call_write_iter include/linux/fs.h:1770 [inline]
 new_sync_write fs/read_write.c:468 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:481
 vfs_write+0x18f/0x510 fs/read_write.c:543
 SYSC_write fs/read_write.c:588 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:580
 entry_SYSCALL_64_fastpath+0x1f/0xbe

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 &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c92e8c02fe664155ac4234516e32544bec0f113d ]

syzkaller found another bug in DCCP/TCP stacks [1]

For the reasons explained in commit ce1050089c96 ("tcp/dccp: fix
ireq-&gt;pktopts race"), we need to make sure we do not access
ireq-&gt;opt unless we own the request sock.

Note the opt field is renamed to ireq_opt to ease grep games.

[1]
BUG: KASAN: use-after-free in ip_queue_xmit+0x1687/0x18e0 net/ipv4/ip_output.c:474
Read of size 1 at addr ffff8801c951039c by task syz-executor5/3295

CPU: 1 PID: 3295 Comm: syz-executor5 Not tainted 4.14.0-rc4+ #80
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
 ip_queue_xmit+0x1687/0x18e0 net/ipv4/ip_output.c:474
 tcp_transmit_skb+0x1ab7/0x3840 net/ipv4/tcp_output.c:1135
 tcp_send_ack.part.37+0x3bb/0x650 net/ipv4/tcp_output.c:3587
 tcp_send_ack+0x49/0x60 net/ipv4/tcp_output.c:3557
 __tcp_ack_snd_check+0x2c6/0x4b0 net/ipv4/tcp_input.c:5072
 tcp_ack_snd_check net/ipv4/tcp_input.c:5085 [inline]
 tcp_rcv_state_process+0x2eff/0x4850 net/ipv4/tcp_input.c:6071
 tcp_child_process+0x342/0x990 net/ipv4/tcp_minisocks.c:816
 tcp_v4_rcv+0x1827/0x2f80 net/ipv4/tcp_ipv4.c:1682
 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:464 [inline]
 ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
 netif_receive_skb+0xae/0x390 net/core/dev.c:4611
 tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
 tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
 call_write_iter include/linux/fs.h:1770 [inline]
 new_sync_write fs/read_write.c:468 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:481
 vfs_write+0x18f/0x510 fs/read_write.c:543
 SYSC_write fs/read_write.c:588 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:580
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x40c341
RSP: 002b:00007f469523ec10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 000000000040c341
RDX: 0000000000000037 RSI: 0000000020004000 RDI: 0000000000000015
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000f4240 R11: 0000000000000293 R12: 00000000004b7fd1
R13: 00000000ffffffff R14: 0000000020000000 R15: 0000000000025000

Allocated by task 3295:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3725 [inline]
 __kmalloc+0x162/0x760 mm/slab.c:3734
 kmalloc include/linux/slab.h:498 [inline]
 tcp_v4_save_options include/net/tcp.h:1962 [inline]
 tcp_v4_init_req+0x2d3/0x3e0 net/ipv4/tcp_ipv4.c:1271
 tcp_conn_request+0xf6d/0x3410 net/ipv4/tcp_input.c:6283
 tcp_v4_conn_request+0x157/0x210 net/ipv4/tcp_ipv4.c:1313
 tcp_rcv_state_process+0x8ea/0x4850 net/ipv4/tcp_input.c:5857
 tcp_v4_do_rcv+0x55c/0x7d0 net/ipv4/tcp_ipv4.c:1482
 tcp_v4_rcv+0x2d10/0x2f80 net/ipv4/tcp_ipv4.c:1711
 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:464 [inline]
 ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
 netif_receive_skb+0xae/0x390 net/core/dev.c:4611
 tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
 tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
 call_write_iter include/linux/fs.h:1770 [inline]
 new_sync_write fs/read_write.c:468 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:481
 vfs_write+0x18f/0x510 fs/read_write.c:543
 SYSC_write fs/read_write.c:588 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:580
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 3306:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xca/0x250 mm/slab.c:3820
 inet_sock_destruct+0x59d/0x950 net/ipv4/af_inet.c:157
 __sk_destruct+0xfd/0x910 net/core/sock.c:1560
 sk_destruct+0x47/0x80 net/core/sock.c:1595
 __sk_free+0x57/0x230 net/core/sock.c:1603
 sk_free+0x2a/0x40 net/core/sock.c:1614
 sock_put include/net/sock.h:1652 [inline]
 inet_csk_complete_hashdance+0xd5/0xf0 net/ipv4/inet_connection_sock.c:959
 tcp_check_req+0xf4d/0x1620 net/ipv4/tcp_minisocks.c:765
 tcp_v4_rcv+0x17f6/0x2f80 net/ipv4/tcp_ipv4.c:1675
 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:464 [inline]
 ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:249 [inline]
 ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
 netif_receive_skb+0xae/0x390 net/core/dev.c:4611
 tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
 tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
 call_write_iter include/linux/fs.h:1770 [inline]
 new_sync_write fs/read_write.c:468 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:481
 vfs_write+0x18f/0x510 fs/read_write.c:543
 SYSC_write fs/read_write.c:588 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:580
 entry_SYSCALL_64_fastpath+0x1f/0xbe

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 &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tcp: fix tcp_mtu_probe() vs highest_sack</title>
<updated>2017-11-18T10:22:21+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2017-10-31T06:08:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e12c42c55287f39bfbaa2ab7e9cf04c88879768f'/>
<id>e12c42c55287f39bfbaa2ab7e9cf04c88879768f</id>
<content type='text'>
[ Upstream commit 2b7cda9c35d3b940eb9ce74b30bbd5eb30db493d ]

Based on SNMP values provided by Roman, Yuchung made the observation
that some crashes in tcp_sacktag_walk() might be caused by MTU probing.

Looking at tcp_mtu_probe(), I found that when a new skb was placed
in front of the write queue, we were not updating tcp highest sack.

If one skb is freed because all its content was copied to the new skb
(for MTU probing), then tp-&gt;highest_sack could point to a now freed skb.

Bad things would then happen, including infinite loops.

This patch renames tcp_highest_sack_combine() and uses it
from tcp_mtu_probe() to fix the bug.

Note that I also removed one test against tp-&gt;sacked_out,
since we want to replace tp-&gt;highest_sack regardless of whatever
condition, since keeping a stale pointer to freed skb is a recipe
for disaster.

Fixes: a47e5a988a57 ("[TCP]: Convert highest_sack to sk_buff to allow direct access")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Alexei Starovoitov &lt;alexei.starovoitov@gmail.com&gt;
Reported-by: Roman Gushchin &lt;guro@fb.com&gt;
Reported-by: Oleksandr Natalenko &lt;oleksandr@natalenko.name&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Acked-by: Yuchung Cheng &lt;ycheng@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 2b7cda9c35d3b940eb9ce74b30bbd5eb30db493d ]

Based on SNMP values provided by Roman, Yuchung made the observation
that some crashes in tcp_sacktag_walk() might be caused by MTU probing.

Looking at tcp_mtu_probe(), I found that when a new skb was placed
in front of the write queue, we were not updating tcp highest sack.

If one skb is freed because all its content was copied to the new skb
(for MTU probing), then tp-&gt;highest_sack could point to a now freed skb.

Bad things would then happen, including infinite loops.

This patch renames tcp_highest_sack_combine() and uses it
from tcp_mtu_probe() to fix the bug.

Note that I also removed one test against tp-&gt;sacked_out,
since we want to replace tp-&gt;highest_sack regardless of whatever
condition, since keeping a stale pointer to freed skb is a recipe
for disaster.

Fixes: a47e5a988a57 ("[TCP]: Convert highest_sack to sk_buff to allow direct access")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Alexei Starovoitov &lt;alexei.starovoitov@gmail.com&gt;
Reported-by: Roman Gushchin &lt;guro@fb.com&gt;
Reported-by: Oleksandr Natalenko &lt;oleksandr@natalenko.name&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Neal Cardwell &lt;ncardwell@google.com&gt;
Acked-by: Yuchung Cheng &lt;ycheng@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netlink: fix nla_put_{u8,u16,u32} for KASAN</title>
<updated>2017-10-12T09:51:25+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2017-09-22T21:29:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9a19bc44c63696db85309148609a963970ad9cc9'/>
<id>9a19bc44c63696db85309148609a963970ad9cc9</id>
<content type='text'>
commit b4391db42308c9940944b5d7be5ca4b78fb88dd0 upstream.

When CONFIG_KASAN is enabled, the "--param asan-stack=1" causes rather large
stack frames in some functions. This goes unnoticed normally because
CONFIG_FRAME_WARN is disabled with CONFIG_KASAN by default as of commit
3f181b4d8652 ("lib/Kconfig.debug: disable -Wframe-larger-than warnings with
KASAN=y").

The kernelci.org build bot however has the warning enabled and that led
me to investigate it a little further, as every build produces these warnings:

net/wireless/nl80211.c:4389:1: warning: the frame size of 2240 bytes is larger than 2048 bytes [-Wframe-larger-than=]
net/wireless/nl80211.c:1895:1: warning: the frame size of 3776 bytes is larger than 2048 bytes [-Wframe-larger-than=]
net/wireless/nl80211.c:1410:1: warning: the frame size of 2208 bytes is larger than 2048 bytes [-Wframe-larger-than=]
net/bridge/br_netlink.c:1282:1: warning: the frame size of 2544 bytes is larger than 2048 bytes [-Wframe-larger-than=]

Most of this problem is now solved in gcc-8, which can consolidate
the stack slots for the inline function arguments. On older compilers
we can add a workaround by declaring a local variable in each function
to pass the inline function argument.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b4391db42308c9940944b5d7be5ca4b78fb88dd0 upstream.

When CONFIG_KASAN is enabled, the "--param asan-stack=1" causes rather large
stack frames in some functions. This goes unnoticed normally because
CONFIG_FRAME_WARN is disabled with CONFIG_KASAN by default as of commit
3f181b4d8652 ("lib/Kconfig.debug: disable -Wframe-larger-than warnings with
KASAN=y").

The kernelci.org build bot however has the warning enabled and that led
me to investigate it a little further, as every build produces these warnings:

net/wireless/nl80211.c:4389:1: warning: the frame size of 2240 bytes is larger than 2048 bytes [-Wframe-larger-than=]
net/wireless/nl80211.c:1895:1: warning: the frame size of 3776 bytes is larger than 2048 bytes [-Wframe-larger-than=]
net/wireless/nl80211.c:1410:1: warning: the frame size of 2208 bytes is larger than 2048 bytes [-Wframe-larger-than=]
net/bridge/br_netlink.c:1282:1: warning: the frame size of 2544 bytes is larger than 2048 bytes [-Wframe-larger-than=]

Most of this problem is now solved in gcc-8, which can consolidate
the stack slots for the inline function arguments. On older compilers
we can add a workaround by declaring a local variable in each function
to pass the inline function argument.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>sctp: potential read out of bounds in sctp_ulpevent_type_enabled()</title>
<updated>2017-10-12T09:51:20+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2017-09-13T23:00:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b70bb9bb7277aa396eafab6a313ee829c7957587'/>
<id>b70bb9bb7277aa396eafab6a313ee829c7957587</id>
<content type='text'>
[ Upstream commit fa5f7b51fc3080c2b195fa87c7eca7c05e56f673 ]

This code causes a static checker warning because Smatch doesn't trust
anything that comes from skb-&gt;data.  I've reviewed this code and I do
think skb-&gt;data can be controlled by the user here.

The sctp_event_subscribe struct has 13 __u8 fields and we want to see
if ours is non-zero.  sn_type can be any value in the 0-USHRT_MAX range.
We're subtracting SCTP_SN_TYPE_BASE which is 1 &lt;&lt; 15 so we could read
either before the start of the struct or after the end.

This is a very old bug and it's surprising that it would go undetected
for so long but my theory is that it just doesn't have a big impact so
it would be hard to notice.

Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fa5f7b51fc3080c2b195fa87c7eca7c05e56f673 ]

This code causes a static checker warning because Smatch doesn't trust
anything that comes from skb-&gt;data.  I've reviewed this code and I do
think skb-&gt;data can be controlled by the user here.

The sctp_event_subscribe struct has 13 __u8 fields and we want to see
if ours is non-zero.  sn_type can be any value in the 0-USHRT_MAX range.
We're subtracting SCTP_SN_TYPE_BASE which is 1 &lt;&lt; 15 so we could read
either before the start of the struct or after the end.

This is a very old bug and it's surprising that it would go undetected
for so long but my theory is that it just doesn't have a big impact so
it would be hard to notice.

Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nf_tables: set pktinfo-&gt;thoff at AH header if found</title>
<updated>2017-10-08T08:26:11+00:00</updated>
<author>
<name>Pablo Neira Ayuso</name>
<email>pablo@netfilter.org</email>
</author>
<published>2017-03-04T18:53:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=625cb13a89295b298d6e0f323cfa2882fb5c05b6'/>
<id>625cb13a89295b298d6e0f323cfa2882fb5c05b6</id>
<content type='text'>
[ Upstream commit 568af6de058cb2b0c5b98d98ffcf37cdc6bc38a7 ]

Phil Sutter reports that IPv6 AH header matching is broken. From
userspace, nft generates bytecode that expects to find the AH header at
NFT_PAYLOAD_TRANSPORT_HEADER both for IPv4 and IPv6. However,
pktinfo-&gt;thoff is set to the inner header after the AH header in IPv6,
while in IPv4 pktinfo-&gt;thoff points to the AH header indeed. This
behaviour is inconsistent. This patch fixes this problem by updating
ipv6_find_hdr() to get the IP6_FH_F_AUTH flag so this function stops at
the AH header, so both IPv4 and IPv6 pktinfo-&gt;thoff point to the AH
header.

This is also inconsistent when trying to match encapsulated headers:

1) A packet that looks like IPv4 + AH + TCP dport 22 will *not* match.
2) A packet that looks like IPv6 + AH + TCP dport 22 will match.

Reported-by: Phil Sutter &lt;phil@nwl.cc&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 568af6de058cb2b0c5b98d98ffcf37cdc6bc38a7 ]

Phil Sutter reports that IPv6 AH header matching is broken. From
userspace, nft generates bytecode that expects to find the AH header at
NFT_PAYLOAD_TRANSPORT_HEADER both for IPv4 and IPv6. However,
pktinfo-&gt;thoff is set to the inner header after the AH header in IPv6,
while in IPv4 pktinfo-&gt;thoff points to the AH header indeed. This
behaviour is inconsistent. This patch fixes this problem by updating
ipv6_find_hdr() to get the IP6_FH_F_AUTH flag so this function stops at
the AH header, so both IPv4 and IPv6 pktinfo-&gt;thoff point to the AH
header.

This is also inconsistent when trying to match encapsulated headers:

1) A packet that looks like IPv4 + AH + TCP dport 22 will *not* match.
2) A packet that looks like IPv6 + AH + TCP dport 22 will match.

Reported-by: Phil Sutter &lt;phil@nwl.cc&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mac80211: fix VLAN handling with TXQs</title>
<updated>2017-10-05T07:43:58+00:00</updated>
<author>
<name>Johannes Berg</name>
<email>johannes.berg@intel.com</email>
</author>
<published>2017-06-22T10:20:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=59862b0429d98f958c44a9e51cb317773ee28ba9'/>
<id>59862b0429d98f958c44a9e51cb317773ee28ba9</id>
<content type='text'>
commit 53168215909281a09d3afc6fb51a9d4f81f74d39 upstream.

With TXQs, the AP_VLAN interfaces are resolved to their owner AP
interface when enqueuing the frame, which makes sense since the
frame really goes out on that as far as the driver is concerned.

However, this introduces a problem: frames to be encrypted with
a VLAN-specific GTK will now be encrypted with the AP GTK, since
the information about which virtual interface to use to select
the key is taken from the TXQ.

Fix this by preserving info-&gt;control.vif and using that in the
dequeue function. This now requires doing the driver-mapping
in the dequeue as well.

Since there's no way to filter the frames that are sitting on a
TXQ, drop all frames, which may affect other interfaces, when an
AP_VLAN is removed.

Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 53168215909281a09d3afc6fb51a9d4f81f74d39 upstream.

With TXQs, the AP_VLAN interfaces are resolved to their owner AP
interface when enqueuing the frame, which makes sense since the
frame really goes out on that as far as the driver is concerned.

However, this introduces a problem: frames to be encrypted with
a VLAN-specific GTK will now be encrypted with the AP GTK, since
the information about which virtual interface to use to select
the key is taken from the TXQ.

Fix this by preserving info-&gt;control.vif and using that in the
dequeue function. This now requires doing the driver-mapping
in the dequeue as well.

Since there's no way to filter the frames that are sitting on a
TXQ, drop all frames, which may affect other interfaces, when an
AP_VLAN is removed.

Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "net: fix percpu memory leaks"</title>
<updated>2017-09-20T06:19:55+00:00</updated>
<author>
<name>Jesper Dangaard Brouer</name>
<email>brouer@redhat.com</email>
</author>
<published>2017-09-01T09:26:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1bcf18718ec63ad5fb025b75a5d2439e1dcf1213'/>
<id>1bcf18718ec63ad5fb025b75a5d2439e1dcf1213</id>
<content type='text'>
[ Upstream commit 5a63643e583b6a9789d7a225ae076fb4e603991c ]

This reverts commit 1d6119baf0610f813eb9d9580eb4fd16de5b4ceb.

After reverting commit 6d7b857d541e ("net: use lib/percpu_counter API
for fragmentation mem accounting") then here is no need for this
fix-up patch.  As percpu_counter is no longer used, it cannot
memory leak it any-longer.

Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting")
Fixes: 1d6119baf061 ("net: fix percpu memory leaks")
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5a63643e583b6a9789d7a225ae076fb4e603991c ]

This reverts commit 1d6119baf0610f813eb9d9580eb4fd16de5b4ceb.

After reverting commit 6d7b857d541e ("net: use lib/percpu_counter API
for fragmentation mem accounting") then here is no need for this
fix-up patch.  As percpu_counter is no longer used, it cannot
memory leak it any-longer.

Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting")
Fixes: 1d6119baf061 ("net: fix percpu memory leaks")
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "net: use lib/percpu_counter API for fragmentation mem accounting"</title>
<updated>2017-09-20T06:19:55+00:00</updated>
<author>
<name>Jesper Dangaard Brouer</name>
<email>brouer@redhat.com</email>
</author>
<published>2017-09-01T09:26:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5a7a40bad254d2571d93059ba4b3963dc448cdb0'/>
<id>5a7a40bad254d2571d93059ba4b3963dc448cdb0</id>
<content type='text'>
[ Upstream commit fb452a1aa3fd4034d7999e309c5466ff2d7005aa ]

This reverts commit 6d7b857d541ecd1d9bd997c97242d4ef94b19de2.

There is a bug in fragmentation codes use of the percpu_counter API,
that can cause issues on systems with many CPUs.

The frag_mem_limit() just reads the global counter (fbc-&gt;count),
without considering other CPUs can have upto batch size (130K) that
haven't been subtracted yet.  Due to the 3MBytes lower thresh limit,
this become dangerous at &gt;=24 CPUs (3*1024*1024/130000=24).

The correct API usage would be to use __percpu_counter_compare() which
does the right thing, and takes into account the number of (online)
CPUs and batch size, to account for this and call __percpu_counter_sum()
when needed.

We choose to revert the use of the lib/percpu_counter API for frag
memory accounting for several reasons:

1) On systems with CPUs &gt; 24, the heavier fully locked
   __percpu_counter_sum() is always invoked, which will be more
   expensive than the atomic_t that is reverted to.

Given systems with more than 24 CPUs are becoming common this doesn't
seem like a good option.  To mitigate this, the batch size could be
decreased and thresh be increased.

2) The add_frag_mem_limit+sub_frag_mem_limit pairs happen on the RX
   CPU, before SKBs are pushed into sockets on remote CPUs.  Given
   NICs can only hash on L2 part of the IP-header, the NIC-RXq's will
   likely be limited.  Thus, a fair chance that atomic add+dec happen
   on the same CPU.

Revert note that commit 1d6119baf061 ("net: fix percpu memory leaks")
removed init_frag_mem_limit() and instead use inet_frags_init_net().
After this revert, inet_frags_uninit_net() becomes empty.

Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting")
Fixes: 1d6119baf061 ("net: fix percpu memory leaks")
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fb452a1aa3fd4034d7999e309c5466ff2d7005aa ]

This reverts commit 6d7b857d541ecd1d9bd997c97242d4ef94b19de2.

There is a bug in fragmentation codes use of the percpu_counter API,
that can cause issues on systems with many CPUs.

The frag_mem_limit() just reads the global counter (fbc-&gt;count),
without considering other CPUs can have upto batch size (130K) that
haven't been subtracted yet.  Due to the 3MBytes lower thresh limit,
this become dangerous at &gt;=24 CPUs (3*1024*1024/130000=24).

The correct API usage would be to use __percpu_counter_compare() which
does the right thing, and takes into account the number of (online)
CPUs and batch size, to account for this and call __percpu_counter_sum()
when needed.

We choose to revert the use of the lib/percpu_counter API for frag
memory accounting for several reasons:

1) On systems with CPUs &gt; 24, the heavier fully locked
   __percpu_counter_sum() is always invoked, which will be more
   expensive than the atomic_t that is reverted to.

Given systems with more than 24 CPUs are becoming common this doesn't
seem like a good option.  To mitigate this, the batch size could be
decreased and thresh be increased.

2) The add_frag_mem_limit+sub_frag_mem_limit pairs happen on the RX
   CPU, before SKBs are pushed into sockets on remote CPUs.  Given
   NICs can only hash on L2 part of the IP-header, the NIC-RXq's will
   likely be limited.  Thus, a fair chance that atomic add+dec happen
   on the same CPU.

Revert note that commit 1d6119baf061 ("net: fix percpu memory leaks")
removed init_frag_mem_limit() and instead use inet_frags_init_net().
After this revert, inet_frags_uninit_net() becomes empty.

Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting")
Fixes: 1d6119baf061 ("net: fix percpu memory leaks")
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
