<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/net/sctp, branch linux-5.16.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.16.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.16.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2022-04-13T18:03:15Z</updated>
<entry>
<title>sctp: count singleton chunks in assoc user stats</title>
<updated>2022-04-13T18:03:15Z</updated>
<author>
<name>Jamie Bainbridge</name>
</author>
<published>2022-04-03T23:47:48Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=a231679929c0401661bdab2c62aa79316e36573d'/>
<id>urn:sha1:a231679929c0401661bdab2c62aa79316e36573d</id>
<content type='text'>
[ Upstream commit e3d37210df5c41c51147a2d5d465de1a4d77be7a ]

Singleton chunks (INIT, HEARTBEAT PMTU probes, and SHUTDOWN-
COMPLETE) are not counted in SCTP_GET_ASOC_STATS "sas_octrlchunks"
counter available to the assoc owner.

These are all control chunks so they should be counted as such.

Add counting of singleton chunks so they are properly accounted for.

Fixes: 196d67593439 ("sctp: Add support to per-association statistics via a new SCTP_GET_ASSOC_STATS call")
Signed-off-by: Jamie Bainbridge &lt;jamie.bainbridge@gmail.com&gt;
Acked-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Link: https://lore.kernel.org/r/c9ba8785789880cf07923b8a5051e174442ea9ee.1649029663.git.jamie.bainbridge@gmail.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>security: add sctp_assoc_established hook</title>
<updated>2022-04-08T12:05:38Z</updated>
<author>
<name>Ondrej Mosnacek</name>
</author>
<published>2022-02-12T17:59:21Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=fa11feb9ca99581242e4dfd1e12cccb5b6bd0aba'/>
<id>urn:sha1:fa11feb9ca99581242e4dfd1e12cccb5b6bd0aba</id>
<content type='text'>
[ Upstream commit 5e50f5d4ff31e95599d695df1f0a4e7d2d6fef99 ]

security_sctp_assoc_established() is added to replace
security_inet_conn_established() called in
sctp_sf_do_5_1E_ca(), so that asoc can be accessed in security
subsystem and save the peer secid to asoc-&gt;peer_secid.

Fixes: 72e89f50084c ("security: Add support for SCTP security hooks")
Reported-by: Prashanth Prahlad &lt;pprahlad@redhat.com&gt;
Based-on-patch-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Reviewed-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Tested-by: Richard Haines &lt;richard_c_haines@btinternet.com&gt;
Signed-off-by: Ondrej Mosnacek &lt;omosnace@redhat.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>sctp: fix kernel-infoleak for SCTP sockets</title>
<updated>2022-03-16T13:26:45Z</updated>
<author>
<name>Eric Dumazet</name>
</author>
<published>2022-03-10T00:11:45Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=d828b0fe6631f3ae8709ac9a10c77c5836c76a08'/>
<id>urn:sha1:d828b0fe6631f3ae8709ac9a10c77c5836c76a08</id>
<content type='text'>
[ Upstream commit 633593a808980f82d251d0ca89730d8bb8b0220c ]

syzbot reported a kernel infoleak [1] of 4 bytes.

After analysis, it turned out r-&gt;idiag_expires is not initialized
if inet_sctp_diag_fill() calls inet_diag_msg_common_fill()

Make sure to clear idiag_timer/idiag_retrans/idiag_expires
and let inet_diag_msg_sctpasoc_fill() fill them again if needed.

[1]

BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline]
BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:154 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668
 instrument_copy_to_user include/linux/instrumented.h:121 [inline]
 copyout lib/iov_iter.c:154 [inline]
 _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668
 copy_to_iter include/linux/uio.h:162 [inline]
 simple_copy_to_iter+0xf3/0x140 net/core/datagram.c:519
 __skb_datagram_iter+0x2d5/0x11b0 net/core/datagram.c:425
 skb_copy_datagram_iter+0xdc/0x270 net/core/datagram.c:533
 skb_copy_datagram_msg include/linux/skbuff.h:3696 [inline]
 netlink_recvmsg+0x669/0x1c80 net/netlink/af_netlink.c:1977
 sock_recvmsg_nosec net/socket.c:948 [inline]
 sock_recvmsg net/socket.c:966 [inline]
 __sys_recvfrom+0x795/0xa10 net/socket.c:2097
 __do_sys_recvfrom net/socket.c:2115 [inline]
 __se_sys_recvfrom net/socket.c:2111 [inline]
 __x64_sys_recvfrom+0x19d/0x210 net/socket.c:2111
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:737 [inline]
 slab_alloc_node mm/slub.c:3247 [inline]
 __kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4975
 kmalloc_reserve net/core/skbuff.c:354 [inline]
 __alloc_skb+0x545/0xf90 net/core/skbuff.c:426
 alloc_skb include/linux/skbuff.h:1158 [inline]
 netlink_dump+0x3e5/0x16c0 net/netlink/af_netlink.c:2248
 __netlink_dump_start+0xcf8/0xe90 net/netlink/af_netlink.c:2373
 netlink_dump_start include/linux/netlink.h:254 [inline]
 inet_diag_handler_cmd+0x2e7/0x400 net/ipv4/inet_diag.c:1341
 sock_diag_rcv_msg+0x24a/0x620
 netlink_rcv_skb+0x40c/0x7e0 net/netlink/af_netlink.c:2494
 sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:277
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x1093/0x1360 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x14d9/0x1720 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 sock_write_iter+0x594/0x690 net/socket.c:1061
 do_iter_readv_writev+0xa7f/0xc70
 do_iter_write+0x52c/0x1500 fs/read_write.c:851
 vfs_writev fs/read_write.c:924 [inline]
 do_writev+0x645/0xe00 fs/read_write.c:967
 __do_sys_writev fs/read_write.c:1040 [inline]
 __se_sys_writev fs/read_write.c:1037 [inline]
 __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Bytes 68-71 of 2508 are uninitialized
Memory access of size 2508 starts at ffff888114f9b000
Data copied to user address 00007f7fe09ff2e0

CPU: 1 PID: 3478 Comm: syz-executor306 Not tainted 5.17.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Vlad Yasevich &lt;vyasevich@gmail.com&gt;
Cc: Neil Horman &lt;nhorman@tuxdriver.com&gt;
Cc: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Reviewed-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Link: https://lore.kernel.org/r/20220310001145.297371-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>sctp: hold endpoint before calling cb in sctp_transport_lookup_process</title>
<updated>2022-01-02T12:46:41Z</updated>
<author>
<name>Xin Long</name>
</author>
<published>2021-12-31T23:37:37Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=f9d31c4cf4c11ff10317f038b9c6f7c3bda6cdd4'/>
<id>urn:sha1:f9d31c4cf4c11ff10317f038b9c6f7c3bda6cdd4</id>
<content type='text'>
The same fix in commit 5ec7d18d1813 ("sctp: use call_rcu to free endpoint")
is also needed for dumping one asoc and sock after the lookup.

Fixes: 86fdb3448cc1 ("sctp: ensure ep is not destroyed before doing the dump")
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>sctp: use call_rcu to free endpoint</title>
<updated>2021-12-25T17:13:37Z</updated>
<author>
<name>Xin Long</name>
</author>
<published>2021-12-23T18:04:30Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=5ec7d18d1813a5bead0b495045606c93873aecbb'/>
<id>urn:sha1:5ec7d18d1813a5bead0b495045606c93873aecbb</id>
<content type='text'>
This patch is to delay the endpoint free by calling call_rcu() to fix
another use-after-free issue in sctp_sock_dump():

  BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20
  Call Trace:
    __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218
    lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844
    __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
    _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
    spin_lock_bh include/linux/spinlock.h:334 [inline]
    __lock_sock+0x203/0x350 net/core/sock.c:2253
    lock_sock_nested+0xfe/0x120 net/core/sock.c:2774
    lock_sock include/net/sock.h:1492 [inline]
    sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:324
    sctp_for_each_transport+0x2b5/0x370 net/sctp/socket.c:5091
    sctp_diag_dump+0x3ac/0x660 net/sctp/diag.c:527
    __inet_diag_dump+0xa8/0x140 net/ipv4/inet_diag.c:1049
    inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1065
    netlink_dump+0x606/0x1080 net/netlink/af_netlink.c:2244
    __netlink_dump_start+0x59a/0x7c0 net/netlink/af_netlink.c:2352
    netlink_dump_start include/linux/netlink.h:216 [inline]
    inet_diag_handler_cmd+0x2ce/0x3f0 net/ipv4/inet_diag.c:1170
    __sock_diag_cmd net/core/sock_diag.c:232 [inline]
    sock_diag_rcv_msg+0x31d/0x410 net/core/sock_diag.c:263
    netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477
    sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:274

This issue occurs when asoc is peeled off and the old sk is freed after
getting it by asoc-&gt;base.sk and before calling lock_sock(sk).

To prevent the sk free, as a holder of the sk, ep should be alive when
calling lock_sock(). This patch uses call_rcu() and moves sock_put and
ep free into sctp_endpoint_destroy_rcu(), so that it's safe to try to
hold the ep under rcu_read_lock in sctp_transport_traverse_process().

If sctp_endpoint_hold() returns true, it means this ep is still alive
and we have held it and can continue to dump it; If it returns false,
it means this ep is dead and can be freed after rcu_read_unlock, and
we should skip it.

In sctp_sock_dump(), after locking the sk, if this ep is different from
tsp-&gt;asoc-&gt;ep, it means during this dumping, this asoc was peeled off
before calling lock_sock(), and the sk should be skipped; If this ep is
the same with tsp-&gt;asoc-&gt;ep, it means no peeloff happens on this asoc,
and due to lock_sock, no peeloff will happen either until release_sock.

Note that delaying endpoint free won't delay the port release, as the
port release happens in sctp_endpoint_destroy() before calling call_rcu().
Also, freeing endpoint by call_rcu() makes it safe to access the sk by
asoc-&gt;base.sk in sctp_assocs_seq_show() and sctp_rcv().

Thanks Jones to bring this issue up.

v1-&gt;v2:
  - improve the changelog.
  - add kfree(ep) into sctp_endpoint_destroy_rcu(), as Jakub noticed.

Reported-by: syzbot+9276d76e83e3bcde6c99@syzkaller.appspotmail.com
Reported-by: Lee Jones &lt;lee.jones@linaro.org&gt;
Fixes: d25adbeb0cdb ("sctp: fix an use-after-free issue in sctp_sock_dump")
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net,lsm,selinux: revert the security_sctp_assoc_established() hook</title>
<updated>2021-11-12T17:07:02Z</updated>
<author>
<name>Paul Moore</name>
</author>
<published>2021-11-12T17:07:02Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=32a370abf12f82c8383e430c21365f5355d8b288'/>
<id>urn:sha1:32a370abf12f82c8383e430c21365f5355d8b288</id>
<content type='text'>
This patch reverts two prior patches, e7310c94024c
("security: implement sctp_assoc_established hook in selinux") and
7c2ef0240e6a ("security: add sctp_assoc_established hook"), which
create the security_sctp_assoc_established() LSM hook and provide a
SELinux implementation.  Unfortunately these two patches were merged
without proper review (the Reviewed-by and Tested-by tags from
Richard Haines were for previous revisions of these patches that
were significantly different) and there are outstanding objections
from the SELinux maintainers regarding these patches.

Work is currently ongoing to correct the problems identified in the
reverted patches, as well as others that have come up during review,
but it is unclear at this point in time when that work will be ready
for inclusion in the mainline kernel.  In the interest of not keeping
objectionable code in the kernel for multiple weeks, and potentially
a kernel release, we are reverting the two problematic patches.

Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'net-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2021-11-11T17:49:36Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2021-11-11T17:49:36Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=f54ca91fe6f25c2028f953ce82f19ca2ea0f07bb'/>
<id>urn:sha1:f54ca91fe6f25c2028f953ce82f19ca2ea0f07bb</id>
<content type='text'>
Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf, can and netfilter.

  Current release - regressions:

   - bpf: do not reject when the stack read size is different from the
     tracked scalar size

   - net: fix premature exit from NAPI state polling in napi_disable()

   - riscv, bpf: fix RV32 broken build, and silence RV64 warning

  Current release - new code bugs:

   - net: fix possible NULL deref in sock_reserve_memory

   - amt: fix error return code in amt_init(); fix stopping the
     workqueue

   - ax88796c: use the correct ioctl callback

  Previous releases - always broken:

   - bpf: stop caching subprog index in the bpf_pseudo_func insn

   - security: fixups for the security hooks in sctp

   - nfc: add necessary privilege flags in netlink layer, limit
     operations to admin only

   - vsock: prevent unnecessary refcnt inc for non-blocking connect

   - net/smc: fix sk_refcnt underflow on link down and fallback

   - nfnetlink_queue: fix OOB when mac header was cleared

   - can: j1939: ignore invalid messages per standard

   - bpf, sockmap:
      - fix race in ingress receive verdict with redirect to self
      - fix incorrect sk_skb data_end access when src_reg = dst_reg
      - strparser, and tls are reusing qdisc_skb_cb and colliding

   - ethtool: fix ethtool msg len calculation for pause stats

   - vlan: fix a UAF in vlan_dev_real_dev() when ref-holder tries to
     access an unregistering real_dev

   - udp6: make encap_rcv() bump the v6 not v4 stats

   - drv: prestera: add explicit padding to fix m68k build

   - drv: felix: fix broken VLAN-tagged PTP under VLAN-aware bridge

   - drv: mvpp2: fix wrong SerDes reconfiguration order

  Misc &amp; small latecomers:

   - ipvs: auto-load ipvs on genl access

   - mctp: sanity check the struct sockaddr_mctp padding fields

   - libfs: support RENAME_EXCHANGE in simple_rename()

   - avoid double accounting for pure zerocopy skbs"

* tag 'net-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (123 commits)
  selftests/net: udpgso_bench_rx: fix port argument
  net: wwan: iosm: fix compilation warning
  cxgb4: fix eeprom len when diagnostics not implemented
  net: fix premature exit from NAPI state polling in napi_disable()
  net/smc: fix sk_refcnt underflow on linkdown and fallback
  net/mlx5: Lag, fix a potential Oops with mlx5_lag_create_definer()
  gve: fix unmatched u64_stats_update_end()
  net: ethernet: lantiq_etop: Fix compilation error
  selftests: forwarding: Fix packet matching in mirroring selftests
  vsock: prevent unnecessary refcnt inc for nonblocking connect
  net: marvell: mvpp2: Fix wrong SerDes reconfiguration order
  net: ethernet: ti: cpsw_ale: Fix access to un-initialized memory
  net: stmmac: allow a tc-taprio base-time of zero
  selftests: net: test_vxlan_under_vrf: fix HV connectivity test
  net: hns3: allow configure ETS bandwidth of all TCs
  net: hns3: remove check VF uc mac exist when set by PF
  net: hns3: fix some mac statistics is always 0 in device version V2
  net: hns3: fix kernel crash when unload VF while it is being reset
  net: hns3: sync rx ring head in echo common pull
  net: hns3: fix pfc packet number incorrect after querying pfc parameters
  ...
</content>
</entry>
<entry>
<title>sctp: remove unreachable code from sctp_sf_violation_chunk()</title>
<updated>2021-11-07T19:32:39Z</updated>
<author>
<name>Alexey Khoroshilov</name>
</author>
<published>2021-11-05T17:30:27Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=e7ea51cd879c8214a824717d28a169b5f2262c02'/>
<id>urn:sha1:e7ea51cd879c8214a824717d28a169b5f2262c02</id>
<content type='text'>
sctp_sf_violation_chunk() is not called with asoc argument equal to NULL,
but if that happens it would lead to NULL pointer dereference
in sctp_vtag_verify().

The patch removes code that handles NULL asoc in sctp_sf_violation_chunk().

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Alexey Khoroshilov &lt;khoroshilov@ispras.ru&gt;
Proposed-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2021-11-06T21:08:17Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2021-11-06T21:08:17Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=512b7931ad0561ffe14265f9ff554a3c081b476b'/>
<id>urn:sha1:512b7931ad0561ffe14265f9ff554a3c081b476b</id>
<content type='text'>
Merge misc updates from Andrew Morton:
 "257 patches.

  Subsystems affected by this patch series: scripts, ocfs2, vfs, and
  mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
  gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
  pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
  memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
  vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
  cleanups, kfence, and damon)"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (257 commits)
  mm/damon: remove return value from before_terminate callback
  mm/damon: fix a few spelling mistakes in comments and a pr_debug message
  mm/damon: simplify stop mechanism
  Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
  Docs/admin-guide/mm/damon/start: simplify the content
  Docs/admin-guide/mm/damon/start: fix a wrong link
  Docs/admin-guide/mm/damon/start: fix wrong example commands
  mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
  mm/damon: remove unnecessary variable initialization
  Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
  mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
  selftests/damon: support watermarks
  mm/damon/dbgfs: support watermarks
  mm/damon/schemes: activate schemes based on a watermarks mechanism
  tools/selftests/damon: update for regions prioritization of schemes
  mm/damon/dbgfs: support prioritization weights
  mm/damon/vaddr,paddr: support pageout prioritization
  mm/damon/schemes: prioritize regions within the quotas
  mm/damon/selftests: support schemes quotas
  mm/damon/dbgfs: support quotas of schemes
  ...
</content>
</entry>
<entry>
<title>include/linux/mm.h: move nr_free_buffer_pages from swap.h to mm.h</title>
<updated>2021-11-06T20:30:43Z</updated>
<author>
<name>Mianhan Liu</name>
</author>
<published>2021-11-05T20:45:21Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=a1554c002699cbc9ced2e9f44f9c1357181bead3'/>
<id>urn:sha1:a1554c002699cbc9ced2e9f44f9c1357181bead3</id>
<content type='text'>
nr_free_buffer_pages could be exposed through mm.h instead of swap.h.
The advantage of this change is that it can reduce the obsolete
includes.  For example, net/ipv4/tcp.c wouldn't need swap.h any more
since it has already included mm.h.  Similarly, after checking all the
other files, it comes that tcp.c, udp.c meter.c ,...  follow the same
rule, so these files can have swap.h removed too.

Moreover, after preprocessing all the files that use
nr_free_buffer_pages, it turns out that those files have already
included mm.h.Thus, we can move nr_free_buffer_pages from swap.h to mm.h
safely.  This change will not affect the compilation of other files.

Link: https://lkml.kernel.org/r/20210912133640.1624-1-liumh1@shanghaitech.edu.cn
Signed-off-by: Mianhan Liu &lt;liumh1@shanghaitech.edu.cn&gt;
Cc: Jakub Kicinski &lt;kuba@kernel.org&gt;
CC: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Cc: "David S . Miller" &lt;davem@davemloft.net&gt;
Cc: Simon Horman &lt;horms@verge.net.au&gt;
Cc: Pravin B Shelar &lt;pshelar@ovn.org&gt;
Cc: Vlad Yasevich &lt;vyasevich@gmail.com&gt;
Cc: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
</feed>
