linux.git/net/core, branch v5.7-rc6 Linux kernel source tree netprio_cgroup: Fix unlimited memory leak of v2 cgroups 2020-05-10T03:59:21+00:00 Zefan Li lizefan@huawei.com 2020-05-09T03:32:10+00:00 090e28b229af92dc5b40786ca673999d59e73056 If systemd is configured to use hybrid mode which enables the use of both cgroup v1 and v2, systemd will create new cgroup on both the default root (v2) and netprio_cgroup hierarchy (v1) for a new session and attach task to the two cgroups. If the task does some network thing then the v2 cgroup can never be freed after the session exited. One of our machines ran into OOM due to this memory leak. In the scenario described above when sk_alloc() is called cgroup_sk_alloc() thought it's in v2 mode, so it stores the cgroup pointer in sk->sk_cgrp_data and increments the cgroup refcnt, but then sock_update_netprioidx() thought it's in v1 mode, so it stores netprioidx value in sk->sk_cgrp_data, so the cgroup refcnt will never be freed. Currently we do the mode switch when someone writes to the ifpriomap cgroup control file. The easiest fix is to also do the switch when a task is attached to a new cgroup. Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") Reported-by: Yang Yingliang <yangyingliang@huawei.com> Tested-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Zefan Li <lizefan@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
If systemd is configured to use hybrid mode which enables the use of
both cgroup v1 and v2, systemd will create new cgroup on both the default
root (v2) and netprio_cgroup hierarchy (v1) for a new session and attach
task to the two cgroups. If the task does some network thing then the v2
cgroup can never be freed after the session exited.

One of our machines ran into OOM due to this memory leak.

In the scenario described above when sk_alloc() is called
cgroup_sk_alloc() thought it's in v2 mode, so it stores
the cgroup pointer in sk->sk_cgrp_data and increments
the cgroup refcnt, but then sock_update_netprioidx()
thought it's in v1 mode, so it stores netprioidx value
in sk->sk_cgrp_data, so the cgroup refcnt will never be freed.

Currently we do the mode switch when someone writes to the ifpriomap
cgroup control file. The easiest fix is to also do the switch when
a task is attached to a new cgroup.

Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup")
Reported-by: Yang Yingliang <yangyingliang@huawei.com>
Tested-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2020-05-09T01:58:39+00:00 Jakub Kicinski kuba@kernel.org 2020-05-09T01:58:39+00:00 14d8f7486a344ee64c37641c70b2d67013eb9de6 Daniel Borkmann says: ==================== pull-request: bpf 2020-05-09 The following pull-request contains BPF updates for your *net* tree. We've added 4 non-merge commits during the last 9 day(s) which contain a total of 4 files changed, 11 insertions(+), 6 deletions(-). The main changes are: 1) Fix msg_pop_data() helper incorrectly setting an sge length in some cases as well as fixing bpf_tcp_ingress() wrongly accounting bytes in sg.size, from John Fastabend. 2) Fix to return an -EFAULT error when copy_to_user() of the value fails in map_lookup_and_delete_elem(), from Wei Yongjun. 3) Fix sk_psock refcnt leak in tcp_bpf_recvmsg(), from Xiyu Yang. ==================== Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Daniel Borkmann says:

====================
pull-request: bpf 2020-05-09

The following pull-request contains BPF updates for your *net* tree.

We've added 4 non-merge commits during the last 9 day(s) which contain
a total of 4 files changed, 11 insertions(+), 6 deletions(-).

The main changes are:

1) Fix msg_pop_data() helper incorrectly setting an sge length in some
   cases as well as fixing bpf_tcp_ingress() wrongly accounting bytes
   in sg.size, from John Fastabend.

2) Fix to return an -EFAULT error when copy_to_user() of the value
   fails in map_lookup_and_delete_elem(), from Wei Yongjun.

3) Fix sk_psock refcnt leak in tcp_bpf_recvmsg(), from Xiyu Yang.
====================

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: fix a potential recursive NETDEV_FEAT_CHANGE 2020-05-08T01:18:36+00:00 Cong Wang xiyou.wangcong@gmail.com 2020-05-07T19:19:03+00:00 dd912306ff008891c82cd9f63e8181e47a9cb2fb syzbot managed to trigger a recursive NETDEV_FEAT_CHANGE event between bonding master and slave. I managed to find a reproducer for this: ip li set bond0 up ifenslave bond0 eth0 brctl addbr br0 ethtool -K eth0 lro off brctl addif br0 bond0 ip li set br0 up When a NETDEV_FEAT_CHANGE event is triggered on a bonding slave, it captures this and calls bond_compute_features() to fixup its master's and other slaves' features. However, when syncing with its lower devices by netdev_sync_lower_features() this event is triggered again on slaves when the LRO feature fails to change, so it goes back and forth recursively until the kernel stack is exhausted. Commit 17b85d29e82c intentionally lets __netdev_update_features() return -1 for such a failure case, so we have to just rely on the existing check inside netdev_sync_lower_features() and skip NETDEV_FEAT_CHANGE event only for this specific failure case. Fixes: fd867d51f889 ("net/core: generic support for disabling netdev features down stack") Reported-by: syzbot+e73ceacfd8560cc8a3ca@syzkaller.appspotmail.com Reported-by: syzbot+c2fb6f9ddcea95ba49b5@syzkaller.appspotmail.com Cc: Jarod Wilson <jarod@redhat.com> Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jann Horn <jannh@google.com> Reviewed-by: Jay Vosburgh <jay.vosburgh@canonical.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
syzbot managed to trigger a recursive NETDEV_FEAT_CHANGE event
between bonding master and slave. I managed to find a reproducer
for this:

  ip li set bond0 up
  ifenslave bond0 eth0
  brctl addbr br0
  ethtool -K eth0 lro off
  brctl addif br0 bond0
  ip li set br0 up

When a NETDEV_FEAT_CHANGE event is triggered on a bonding slave,
it captures this and calls bond_compute_features() to fixup its
master's and other slaves' features. However, when syncing with
its lower devices by netdev_sync_lower_features() this event is
triggered again on slaves when the LRO feature fails to change,
so it goes back and forth recursively until the kernel stack is
exhausted.

Commit 17b85d29e82c intentionally lets __netdev_update_features()
return -1 for such a failure case, so we have to just rely on
the existing check inside netdev_sync_lower_features() and skip
NETDEV_FEAT_CHANGE event only for this specific failure case.

Fixes: fd867d51f889 ("net/core: generic support for disabling netdev features down stack")
Reported-by: syzbot+e73ceacfd8560cc8a3ca@syzkaller.appspotmail.com
Reported-by: syzbot+c2fb6f9ddcea95ba49b5@syzkaller.appspotmail.com
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jann Horn <jannh@google.com>
Reviewed-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf, sockmap: msg_pop_data can incorrecty set an sge length 2020-05-05T22:22:15+00:00 John Fastabend john.fastabend@gmail.com 2020-05-04T17:21:23+00:00 3e104c23816220919ea1b3fd93fabe363c67c484 When sk_msg_pop() is called where the pop operation is working on the end of a sge element and there is no additional trailing data and there _is_ data in front of pop, like the following case, |____________a_____________|__pop__| We have out of order operations where we incorrectly set the pop variable so that instead of zero'ing pop we incorrectly leave it untouched, effectively. This can cause later logic to shift the buffers around believing it should pop extra space. The result is we have 'popped' more data then we expected potentially breaking program logic. It took us a while to hit this case because typically we pop headers which seem to rarely be at the end of a scatterlist elements but we can't rely on this. Fixes: 7246d8ed4dcce ("bpf: helper to pop data from messages") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/158861288359.14306.7654891716919968144.stgit@john-Precision-5820-Tower 
When sk_msg_pop() is called where the pop operation is working on
the end of a sge element and there is no additional trailing data
and there _is_ data in front of pop, like the following case,

   |____________a_____________|__pop__|

We have out of order operations where we incorrectly set the pop
variable so that instead of zero'ing pop we incorrectly leave it
untouched, effectively. This can cause later logic to shift the
buffers around believing it should pop extra space. The result is
we have 'popped' more data then we expected potentially breaking
program logic.

It took us a while to hit this case because typically we pop headers
which seem to rarely be at the end of a scatterlist elements but
we can't rely on this.

Fixes: 7246d8ed4dcce ("bpf: helper to pop data from messages")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/158861288359.14306.7654891716919968144.stgit@john-Precision-5820-Tower
neigh: send protocol value in neighbor create notification 2020-05-05T20:38:59+00:00 Roman Mashak mrv@mojatatu.com 2020-05-02T01:34:18+00:00 38212bb31fe923d0a2c6299bd2adfbb84cddef2a When a new neighbor entry has been added, event is generated but it does not include protocol, because its value is assigned after the event notification routine has run, so move protocol assignment code earlier. Fixes: df9b0e30d44c ("neighbor: Add protocol attribute") Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Roman Mashak <mrv@mojatatu.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When a new neighbor entry has been added, event is generated but it does not
include protocol, because its value is assigned after the event notification
routine has run, so move protocol assignment code earlier.

Fixes: df9b0e30d44c ("neighbor: Add protocol attribute")
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Roman Mashak <mrv@mojatatu.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
devlink: Fix reporter's recovery condition 2020-05-04T17:40:39+00:00 Aya Levin ayal@mellanox.com 2020-05-04T08:27:46+00:00 bea0c5c942d3b4e9fb6ed45f6a7de74c6b112437 Devlink health core conditions the reporter's recovery with the expiration of the grace period. This is not relevant for the first recovery. Explicitly demand that the grace period will only apply to recoveries other than the first. Fixes: c8e1da0bf923 ("devlink: Add health report functionality") Signed-off-by: Aya Levin <ayal@mellanox.com> Reviewed-by: Moshe Shemesh <moshe@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Devlink health core conditions the reporter's recovery with the
expiration of the grace period. This is not relevant for the first
recovery. Explicitly demand that the grace period will only apply to
recoveries other than the first.

Fixes: c8e1da0bf923 ("devlink: Add health report functionality")
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drop_monitor: work around gcc-10 stringop-overflow warning 2020-05-01T22:45:16+00:00 Arnd Bergmann arnd@arndb.de 2020-04-30T21:30:49+00:00 dc30b4059f6e2abf3712ab537c8718562b21c45d The current gcc-10 snapshot produces a false-positive warning: net/core/drop_monitor.c: In function 'trace_drop_common.constprop': cc1: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=] In file included from net/core/drop_monitor.c:23: include/uapi/linux/net_dropmon.h:36:8: note: at offset 0 to object 'entries' with size 4 declared here 36 | __u32 entries; | ^~~~~~~ I reported this in the gcc bugzilla, but in case it does not get fixed in the release, work around it by using a temporary variable. Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol") Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94881 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The current gcc-10 snapshot produces a false-positive warning:

net/core/drop_monitor.c: In function 'trace_drop_common.constprop':
cc1: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=]
In file included from net/core/drop_monitor.c:23:
include/uapi/linux/net_dropmon.h:36:8: note: at offset 0 to object 'entries' with size 4 declared here
   36 |  __u32 entries;
      |        ^~~~~~~

I reported this in the gcc bugzilla, but in case it does not get
fixed in the release, work around it by using a temporary variable.

Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol")
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94881
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
devlink: fix return value after hitting end in region read 2020-05-01T22:25:35+00:00 Jakub Kicinski kuba@kernel.org 2020-04-29T02:01:58+00:00 610a9346c138b9c2c93d38bf5f3728e74ae9cbd5 Commit d5b90e99e1d5 ("devlink: report 0 after hitting end in region read") fixed region dump, but region read still returns a spurious error: $ devlink region read netdevsim/netdevsim1/dummy snapshot 0 addr 0 len 128 0000000000000000 a6 f4 c4 1c 21 35 95 a6 9d 34 c3 5b 87 5b 35 79 0000000000000010 f3 a0 d7 ee 4f 2f 82 7f c6 dd c4 f6 a5 c3 1b ae 0000000000000020 a4 fd c8 62 07 59 48 03 70 3b c7 09 86 88 7f 68 0000000000000030 6f 45 5d 6d 7d 0e 16 38 a9 d0 7a 4b 1e 1e 2e a6 0000000000000040 e6 1d ae 06 d6 18 00 85 ca 62 e8 7e 11 7e f6 0f 0000000000000050 79 7e f7 0f f3 94 68 bd e6 40 22 85 b6 be 6f b1 0000000000000060 af db ef 5e 34 f0 98 4b 62 9a e3 1b 8b 93 fc 17 devlink answers: Invalid argument 0000000000000070 61 e8 11 11 66 10 a5 f7 b1 ea 8d 40 60 53 ed 12 This is a minimal fix, I'll follow up with a restructuring so we don't have two checks for the same condition. Fixes: fdd41ec21e15 ("devlink: Return right error code in case of errors for region read") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Commit d5b90e99e1d5 ("devlink: report 0 after hitting end in region read")
fixed region dump, but region read still returns a spurious error:

$ devlink region read netdevsim/netdevsim1/dummy snapshot 0 addr 0 len 128
0000000000000000 a6 f4 c4 1c 21 35 95 a6 9d 34 c3 5b 87 5b 35 79
0000000000000010 f3 a0 d7 ee 4f 2f 82 7f c6 dd c4 f6 a5 c3 1b ae
0000000000000020 a4 fd c8 62 07 59 48 03 70 3b c7 09 86 88 7f 68
0000000000000030 6f 45 5d 6d 7d 0e 16 38 a9 d0 7a 4b 1e 1e 2e a6
0000000000000040 e6 1d ae 06 d6 18 00 85 ca 62 e8 7e 11 7e f6 0f
0000000000000050 79 7e f7 0f f3 94 68 bd e6 40 22 85 b6 be 6f b1
0000000000000060 af db ef 5e 34 f0 98 4b 62 9a e3 1b 8b 93 fc 17
devlink answers: Invalid argument
0000000000000070 61 e8 11 11 66 10 a5 f7 b1 ea 8d 40 60 53 ed 12

This is a minimal fix, I'll follow up with a restructuring
so we don't have two checks for the same condition.

Fixes: fdd41ec21e15 ("devlink: Return right error code in case of errors for region read")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: remove obsolete comment 2020-04-26T03:49:32+00:00 Eric Dumazet edumazet@google.com 2020-04-25T01:39:29+00:00 52a90612fa6108d20cffd3cf6a2c228e2f3619f7 Commit b656722906ef ("net: Increase the size of skb_frag_t") removed the 16bit limitation of a frag on some 32bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Commit b656722906ef ("net: Increase the size of skb_frag_t")
removed the 16bit limitation of a frag on some 32bit arches.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cgroup, netclassid: remove double cond_resched 2020-04-21T22:44:30+00:00 Jiri Slaby jslaby@suse.cz 2020-04-20T07:04:24+00:00 526f3d96b8f83b1b13d73bd0b5c79cc2c487ec8e Commit 018d26fcd12a ("cgroup, netclassid: periodically release file_lock on classid") added a second cond_resched to write_classid indirectly by update_classid_task. Remove the one in write_classid. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Dmitry Yakunin <zeil@yandex-team.ru> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
Commit 018d26fcd12a ("cgroup, netclassid: periodically release file_lock
on classid") added a second cond_resched to write_classid indirectly by
update_classid_task. Remove the one in write_classid.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Dmitry Yakunin <zeil@yandex-team.ru>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>