Luiz Augusto von Dentz says:

====================
bluetooth pull request for net:

 - Fix building with coredump disabled
 - Fix use-after-free in hci_remove_adv_monitor
 - Use RCU for hci_conn_params and iterate safely in hci_sync
 - Fix locking issues on ISO and SCO
 - Fix bluetooth on Intel Macbook 2014

* tag 'for-net-2023-07-20' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: MGMT: Use correct address for memcpy()
  Bluetooth: btusb: Fix bluetooth on Intel Macbook 2014
  Bluetooth: SCO: fix sco_conn related locking and validity issues
  Bluetooth: hci_conn: return ERR_PTR instead of NULL when there is no link
  Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor()
  Bluetooth: coredump: fix building with coredump disabled
  Bluetooth: ISO: fix iso_conn related locking and validity issues
  Bluetooth: hci_event: call disconnect callback before deleting conn
  Bluetooth: use RCU for hci_conn_params and iterate safely in hci_sync
====================

Link: https://lore.kernel.org/r/20230720190201.446469-1-luiz.dentz@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Florian Westphal says:

====================
Netfilter fixes for net:

The following patchset contains Netfilter fixes for net:

1. Fix spurious -EEXIST error from userspace due to
   padding holes, this was broken since 4.9 days
   when 'ignore duplicate entries on insert' feature was
   added.

2. Fix a sched-while-atomic bug, present since 5.19.

3. Properly remove elements if they lack an "end range".
   nft userspace always sets an end range attribute, even
   when its the same as the start, but the abi doesn't
   have such a restriction. Always broken since it was
   added in 5.6, all three from myself.

4 + 5: Bound chain needs to be skipped in netns release
   and on rule flush paths, from Pablo Neira.

* tag 'nf-23-07-20' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nf_tables: skip bound chain on rule flush
  netfilter: nf_tables: skip bound chain in netns release path
  netfilter: nft_set_pipapo: fix improper element removal
  netfilter: nf_tables: can't schedule in nft_chain_validate
  netfilter: nf_tables: fix spurious set element insertion failure
====================

Link: https://lore.kernel.org/r/20230720165143.30208-1-fw@strlen.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

mdio_bus_init() and phy_driver_register() both have error paths, and if
those are ever hit, ethtool will have a stale pointer to the
phy_ethtool_phy_ops stub structure, which references memory from a
module that failed to load (phylib).

It is probably hard to force an error in this code path even manually,
but the error teardown path of phy_init() should be the same as
phy_exit(), which is now simply not the case.

Fixes: 55d8f053 ("net: phy: Register ethtool PHY operations")
Link: https://lore.kernel.org/netdev/ZLaiJ4G6TaJYGJyU@shell.armlinux.org.uk/Suggested-by: Russell King (Oracle) <linux@armlinux.org.uk>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230720000231.1939689-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Eric Dumazet says:

====================
tcp: add missing annotations

This series was inspired by one syzbot (KCSAN) report.

do_tcp_getsockopt() does not lock the socket, we need to
annotate most of the reads there (and other places as well).

This is a first round, another series will come later.
====================

Link: https://lore.kernel.org/r/20230719212857.3943972-1-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This field can be read locklessly.

Fixes: 1536e285 ("tcp: Add a TCP_FASTOPEN socket option to get a max backlog on its listner")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-12-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This field can be read locklessly from do_tcp_getsockopt()

Fixes: dca43c75 ("tcp: Add TCP_USER_TIMEOUT socket option.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-11-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tp->notsent_lowat can be read locklessly from do_tcp_getsockopt()
and tcp_poll().

Fixes: c9bee3b7 ("tcp: TCP_NOTSENT_LOWAT socket option")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-10-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

do_tcp_getsockopt() reads rskq_defer_accept while another cpu
might change its value.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-9-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

do_tcp_getsockopt() reads tp->linger2 while another cpu
might change its value.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-8-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

do_tcp_getsockopt() and reqsk_timer_handler() read
icsk->icsk_syn_retries while another cpu might change its value.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-7-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

do_tcp_getsockopt() reads tp->keepalive_probes while another cpu
might change its value.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-6-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

do_tcp_getsockopt() reads tp->keepalive_intvl while another cpu
might change its value.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-5-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

do_tcp_getsockopt() reads tp->keepalive_time while another cpu
might change its value.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-4-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

do_tcp_getsockopt() reads tp->tsoffset while another cpu
might change its value.

Fixes: 93be6ce0 ("tcp: set and get per-socket timestamp")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-3-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

do_tcp_getsockopt() reads tp->tcp_tx_delay while another cpu
might change its value.

Fixes: a842fe14 ("tcp: add optional per socket transmit delay")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-2-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

In function ‘fortify_memcpy_chk’,
    inlined from ‘get_conn_info_complete’ at net/bluetooth/mgmt.c:7281:2:
include/linux/fortify-string.h:592:25: error: call to
‘__read_overflow2_field’ declared with attribute warning: detected read
beyond size of field (2nd parameter); maybe use struct_group()?
[-Werror=attribute-warning]
  592 |                         __read_overflow2_field(q_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

This is due to the wrong member is used for memcpy(). Use correct one.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Commit c13380a5 ("Bluetooth: btusb: Do not require hardcoded
interface numbers") inadvertedly broke bluetooth on Intel Macbook 2014.
The intention was to keep behavior intact when BTUSB_IFNUM_2 is set and
otherwise allow any interface numbers. The problem is that the new logic
condition omits the case where bInterfaceNumber is 0.

Fix BTUSB_IFNUM_2 handling by allowing both interface number 0 and 2
when the flag is set.

Fixes: c13380a5 ("Bluetooth: btusb: Do not require hardcoded interface numbers")
Reported-by: John Holland <johnbholland@icloud.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217651Signed-off-by: Tomasz Moń <tomasz.mon@nordicsemi.no>
Tested-by: John Holland<johnbholland@icloud.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Operations that check/update sk_state and access conn should hold
lock_sock, otherwise they can race.

The order of taking locks is hci_dev_lock > lock_sock > sco_conn_lock,
which is how it is in connect/disconnect_cfm -> sco_conn_del ->
sco_chan_del.

Fix locking in sco_connect to take lock_sock around updating sk_state
and conn.

sco_conn_del must not occur during sco_connect, as it frees the
sco_conn. Hold hdev->lock longer to prevent that.

sco_conn_add shall return sco_conn with valid hcon. Make it so also when
reusing an old SCO connection waiting for disconnect timeout (see
__sco_sock_close where conn->hcon is set to NULL).

This should not reintroduce the issue fixed in the earlier
commit 9a8ec9e8 ("Bluetooth: SCO: Fix possible circular locking
dependency on sco_connect_cfm"), the relevant fix of releasing lock_sock
in sco_sock_connect before acquiring hdev->lock is retained.

These changes mirror similar fixes earlier in ISO sockets.

Fixes: 9a8ec9e8 ("Bluetooth: SCO: Fix possible circular locking dependency on sco_connect_cfm")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

hci_connect_sco currently returns NULL when there is no link (i.e. when
hci_conn_link() returns NULL).

sco_connect() expects an ERR_PTR in case of any error (see line 266 in
sco.c). Thus, hcon set as NULL passes through to sco_conn_add(), which
tries to get hcon->hdev, resulting in dereferencing a NULL pointer as
reported by syzkaller.

The same issue exists for iso_connect_cis() calling hci_connect_cis().

Thus, make hci_connect_sco() and hci_connect_cis() return ERR_PTR
instead of NULL.

Reported-and-tested-by: syzbot+37acd5d80d00d609d233@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=37acd5d80d00d609d233
Fixes: 06149746 ("Bluetooth: hci_conn: Add support for linking multiple hcon")
Signed-off-by: Siddh Raman Pant <code@siddh.me>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

KASAN reports that there's a use-after-free in
hci_remove_adv_monitor(). Trawling through the disassembly, you can
see that the complaint is from the access in bt_dev_dbg() under the
HCI_ADV_MONITOR_EXT_MSFT case. The problem case happens because
msft_remove_monitor() can end up freeing the monitor
structure. Specifically:
  hci_remove_adv_monitor() ->
  msft_remove_monitor() ->
  msft_remove_monitor_sync() ->
  msft_le_cancel_monitor_advertisement_cb() ->
  hci_free_adv_monitor()

Let's fix the problem by just stashing the relevant data when it's
still valid.

Fixes: 7cf5c297 ("Bluetooth: hci_sync: Refactor remove Adv Monitor")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

The btmtk driver uses an IS_ENABLED() check to conditionally compile
the coredump support, but this fails to build because the hdev->dump
member is in an #ifdef:

drivers/bluetooth/btmtk.c: In function 'btmtk_process_coredump':
drivers/bluetooth/btmtk.c:386:30: error: 'struct hci_dev' has no member named 'dump'
  386 |   schedule_delayed_work(&hdev->dump.dump_timeout,
      |                              ^~

The struct member doesn't really make a huge difference in the total size,
so just remove the #ifdef around it to avoid adding similar checks
around each user.

Fixes: 872f8c253cb9e ("Bluetooth: btusb: mediatek: add MediaTek devcoredump support")
Fixes: 9695ef87 ("Bluetooth: Add support for hci devcoredump")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

sk->sk_state indicates whether iso_pi(sk)->conn is valid. Operations
that check/update sk_state and access conn should hold lock_sock,
otherwise they can race.

The order of taking locks is hci_dev_lock > lock_sock > iso_conn_lock,
which is how it is in connect/disconnect_cfm -> iso_conn_del ->
iso_chan_del.

Fix locking in iso_connect_cis/bis and sendmsg/recvmsg to take lock_sock
around updating sk_state and conn.

iso_conn_del must not occur during iso_connect_cis/bis, as it frees the
iso_conn. Hold hdev->lock longer to prevent that.

This should not reintroduce the issue fixed in commit 241f5193
("Bluetooth: ISO: Avoid circular locking dependency"), since the we
acquire locks in order. We retain the fix in iso_sock_connect to release
lock_sock before iso_connect_* acquires hdev->lock.

Similarly for commit 6a5ad251 ("Bluetooth: ISO: Fix possible
circular locking dependency"). We retain the fix in iso_conn_ready to
not acquire iso_conn_lock before lock_sock.

iso_conn_add shall return iso_conn with valid hcon. Make it so also when
reusing an old CIS connection waiting for disconnect timeout (see
__iso_sock_close where conn->hcon is set to NULL).

Trace with iso_conn_del after iso_chan_add in iso_connect_cis:
===============================================================
iso_sock_create:771: sock 00000000be9b69b7
iso_sock_init:693: sk 000000004dff667e
iso_sock_bind:827: sk 000000004dff667e 70:1a:b8:98:ff:a2 type 1
iso_sock_setsockopt:1289: sk 000000004dff667e
iso_sock_setsockopt:1289: sk 000000004dff667e
iso_sock_setsockopt:1289: sk 000000004dff667e
iso_sock_connect:875: sk 000000004dff667e
iso_connect_cis:353: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da
hci_get_route:1199: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da
hci_conn_add:1005: hci0 dst 28:3d:c2:4a:7e:da
iso_conn_add:140: hcon 000000007b65d182 conn 00000000daf8625e
__iso_chan_add:214: conn 00000000daf8625e
iso_connect_cfm:1700: hcon 000000007b65d182 bdaddr 28:3d:c2:4a:7e:da status 12
iso_conn_del:187: hcon 000000007b65d182 conn 00000000daf8625e, err 16
iso_sock_clear_timer:117: sock 000000004dff667e state 3
    <Note: sk_state is BT_BOUND (3), so iso_connect_cis is still
    running at this point>
iso_chan_del:153: sk 000000004dff667e, conn 00000000daf8625e, err 16
hci_conn_del:1151: hci0 hcon 000000007b65d182 handle 65535
hci_conn_unlink:1102: hci0: hcon 000000007b65d182
hci_chan_list_flush:2780: hcon 000000007b65d182
iso_sock_getsockopt:1376: sk 000000004dff667e
iso_sock_getname:1070: sock 00000000be9b69b7, sk 000000004dff667e
iso_sock_getname:1070: sock 00000000be9b69b7, sk 000000004dff667e
iso_sock_getsockopt:1376: sk 000000004dff667e
iso_sock_getname:1070: sock 00000000be9b69b7, sk 000000004dff667e
iso_sock_getname:1070: sock 00000000be9b69b7, sk 000000004dff667e
iso_sock_shutdown:1434: sock 00000000be9b69b7, sk 000000004dff667e, how 1
__iso_sock_close:632: sk 000000004dff667e state 5 socket 00000000be9b69b7
     <Note: sk_state is BT_CONNECT (5), even though iso_chan_del sets
     BT_CLOSED (6). Only iso_connect_cis sets it to BT_CONNECT, so it
     must be that iso_chan_del occurred between iso_chan_add and end of
     iso_connect_cis.>
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 8000000006467067 P4D 8000000006467067 PUD 3f5f067 PMD 0
Oops: 0000 [#1] PREEMPT SMP PTI
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
RIP: 0010:__iso_sock_close (net/bluetooth/iso.c:664) bluetooth
===============================================================

Trace with iso_conn_del before iso_chan_add in iso_connect_cis:
===============================================================
iso_connect_cis:356: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da
...
iso_conn_add:140: hcon 0000000093bc551f conn 00000000768ae504
hci_dev_put:1487: hci0 orig refcnt 21
hci_event_packet:7607: hci0: event 0x0e
hci_cmd_complete_evt:4231: hci0: opcode 0x2062
hci_cc_le_set_cig_params:3846: hci0: status 0x07
hci_sent_cmd_data:3107: hci0 opcode 0x2062
iso_connect_cfm:1703: hcon 0000000093bc551f bdaddr 28:3d:c2:4a:7e:da status 7
iso_conn_del:187: hcon 0000000093bc551f conn 00000000768ae504, err 12
hci_conn_del:1151: hci0 hcon 0000000093bc551f handle 65535
hci_conn_unlink:1102: hci0: hcon 0000000093bc551f
hci_chan_list_flush:2780: hcon 0000000093bc551f
__iso_chan_add:214: conn 00000000768ae504
    <Note: this conn was already freed in iso_conn_del above>
iso_sock_clear_timer:117: sock 0000000098323f95 state 3
general protection fault, probably for non-canonical address 0x30b29c630930aec8: 0000 [#1] PREEMPT SMP PTI
CPU: 1 PID: 1920 Comm: bluetoothd Tainted: G            E      6.3.0-rc7+ #4
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
RIP: 0010:detach_if_pending+0x28/0xd0
Code: 90 90 0f 1f 44 00 00 48 8b 47 08 48 85 c0 0f 84 ad 00 00 00 55 89 d5 53 48 83 3f 00 48 89 fb 74 7d 66 90 48 8b 03 48 8b 53 08 <>
RSP: 0018:ffffb90841a67d08 EFLAGS: 00010007
RAX: 0000000000000000 RBX: ffff9141bd5061b8 RCX: 0000000000000000
RDX: 30b29c630930aec8 RSI: ffff9141fdd21e80 RDI: ffff9141bd5061b8
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffb90841a67b88
R10: 0000000000000003 R11: ffffffff8613f558 R12: ffff9141fdd21e80
R13: 0000000000000000 R14: ffff9141b5976010 R15: ffff914185755338
FS:  00007f45768bd840(0000) GS:ffff9141fdd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000619000424074 CR3: 0000000009f5e005 CR4: 0000000000170ee0
Call Trace:
 <TASK>
 timer_delete+0x48/0x80
 try_to_grab_pending+0xdf/0x170
 __cancel_work+0x37/0xb0
 iso_connect_cis+0x141/0x400 [bluetooth]
===============================================================

Trace with NULL conn->hcon in state BT_CONNECT:
===============================================================
__iso_sock_close:619: sk 00000000f7c71fc5 state 1 socket 00000000d90c5fe5
...
__iso_sock_close:619: sk 00000000f7c71fc5 state 8 socket 00000000d90c5fe5
iso_chan_del:153: sk 00000000f7c71fc5, conn 0000000022c03a7e, err 104
...
iso_sock_connect:862: sk 00000000129b56c3
iso_connect_cis:348: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7d:2a
hci_get_route:1199: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7d:2a
hci_dev_hold:1495: hci0 orig refcnt 19
__iso_chan_add:214: conn 0000000022c03a7e
    <Note: reusing old conn>
iso_sock_clear_timer:117: sock 00000000129b56c3 state 3
...
iso_sock_ready:1485: sk 00000000129b56c3
...
iso_sock_sendmsg:1077: sock 00000000e5013966, sk 00000000129b56c3
BUG: kernel NULL pointer dereference, address: 00000000000006a8
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 1 PID: 1403 Comm: wireplumber Tainted: G            E      6.3.0-rc7+ #4
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
RIP: 0010:iso_sock_sendmsg+0x63/0x2a0 [bluetooth]
===============================================================

Fixes: 241f5193 ("Bluetooth: ISO: Avoid circular locking dependency")
Fixes: 6a5ad251 ("Bluetooth: ISO: Fix possible circular locking dependency")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

In hci_cs_disconnect, we do hci_conn_del even if disconnection failed.

ISO, L2CAP and SCO connections refer to the hci_conn without
hci_conn_get, so disconn_cfm must be called so they can clean up their
conn, otherwise use-after-free occurs.

ISO:
==========================================================
iso_sock_connect:880: sk 00000000eabd6557
iso_connect_cis:356: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da
...
iso_conn_add:140: hcon 000000001696f1fd conn 00000000b6251073
hci_dev_put:1487: hci0 orig refcnt 17
__iso_chan_add:214: conn 00000000b6251073
iso_sock_clear_timer:117: sock 00000000eabd6557 state 3
...
hci_rx_work:4085: hci0 Event packet
hci_event_packet:7601: hci0: event 0x0f
hci_cmd_status_evt:4346: hci0: opcode 0x0406
hci_cs_disconnect:2760: hci0: status 0x0c
hci_sent_cmd_data:3107: hci0 opcode 0x0406
hci_conn_del:1151: hci0 hcon 000000001696f1fd handle 2560
hci_conn_unlink:1102: hci0: hcon 000000001696f1fd
hci_conn_drop:1451: hcon 00000000d8521aaf orig refcnt 2
hci_chan_list_flush:2780: hcon 000000001696f1fd
hci_dev_put:1487: hci0 orig refcnt 21
hci_dev_put:1487: hci0 orig refcnt 20
hci_req_cmd_complete:3978: opcode 0x0406 status 0x0c
... <no iso_* activity on sk/conn> ...
iso_sock_sendmsg:1098: sock 00000000dea5e2e0, sk 00000000eabd6557
BUG: kernel NULL pointer dereference, address: 0000000000000668
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
RIP: 0010:iso_sock_sendmsg (net/bluetooth/iso.c:1112) bluetooth
==========================================================

L2CAP:
==================================================================
hci_cmd_status_evt:4359: hci0: opcode 0x0406
hci_cs_disconnect:2760: hci0: status 0x0c
hci_sent_cmd_data:3085: hci0 opcode 0x0406
hci_conn_del:1151: hci0 hcon ffff88800c999000 handle 3585
hci_conn_unlink:1102: hci0: hcon ffff88800c999000
hci_chan_list_flush:2780: hcon ffff88800c999000
hci_chan_del:2761: hci0 hcon ffff88800c999000 chan ffff888018ddd280
...
BUG: KASAN: slab-use-after-free in hci_send_acl+0x2d/0x540 [bluetooth]
Read of size 8 at addr ffff888018ddd298 by task bluetoothd/1175

CPU: 0 PID: 1175 Comm: bluetoothd Tainted: G            E      6.4.0-rc4+ #2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x5b/0x90
 print_report+0xcf/0x670
 ? __virt_addr_valid+0xf8/0x180
 ? hci_send_acl+0x2d/0x540 [bluetooth]
 kasan_report+0xa8/0xe0
 ? hci_send_acl+0x2d/0x540 [bluetooth]
 hci_send_acl+0x2d/0x540 [bluetooth]
 ? __pfx___lock_acquire+0x10/0x10
 l2cap_chan_send+0x1fd/0x1300 [bluetooth]
 ? l2cap_sock_sendmsg+0xf2/0x170 [bluetooth]
 ? __pfx_l2cap_chan_send+0x10/0x10 [bluetooth]
 ? lock_release+0x1d5/0x3c0
 ? mark_held_locks+0x1a/0x90
 l2cap_sock_sendmsg+0x100/0x170 [bluetooth]
 sock_write_iter+0x275/0x280
 ? __pfx_sock_write_iter+0x10/0x10
 ? __pfx___lock_acquire+0x10/0x10
 do_iter_readv_writev+0x176/0x220
 ? __pfx_do_iter_readv_writev+0x10/0x10
 ? find_held_lock+0x83/0xa0
 ? selinux_file_permission+0x13e/0x210
 do_iter_write+0xda/0x340
 vfs_writev+0x1b4/0x400
 ? __pfx_vfs_writev+0x10/0x10
 ? __seccomp_filter+0x112/0x750
 ? populate_seccomp_data+0x182/0x220
 ? __fget_light+0xdf/0x100
 ? do_writev+0x19d/0x210
 do_writev+0x19d/0x210
 ? __pfx_do_writev+0x10/0x10
 ? mark_held_locks+0x1a/0x90
 do_syscall_64+0x60/0x90
 ? lockdep_hardirqs_on_prepare+0x149/0x210
 ? do_syscall_64+0x6c/0x90
 ? lockdep_hardirqs_on_prepare+0x149/0x210
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7ff45cb23e64
Code: 15 d1 1f 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d 9d a7 0d 00 00 74 13 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89
RSP: 002b:00007fff21ae09b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007ff45cb23e64
RDX: 0000000000000001 RSI: 00007fff21ae0aa0 RDI: 0000000000000017
RBP: 00007fff21ae0aa0 R08: 000000000095a8a0 R09: 0000607000053f40
R10: 0000000000000001 R11: 0000000000000202 R12: 00007fff21ae0ac0
R13: 00000fffe435c150 R14: 00007fff21ae0a80 R15: 000060f000000040
 </TASK>

Allocated by task 771:
 kasan_save_stack+0x33/0x60
 kasan_set_track+0x25/0x30
 __kasan_kmalloc+0xaa/0xb0
 hci_chan_create+0x67/0x1b0 [bluetooth]
 l2cap_conn_add.part.0+0x17/0x590 [bluetooth]
 l2cap_connect_cfm+0x266/0x6b0 [bluetooth]
 hci_le_remote_feat_complete_evt+0x167/0x310 [bluetooth]
 hci_event_packet+0x38d/0x800 [bluetooth]
 hci_rx_work+0x287/0xb20 [bluetooth]
 process_one_work+0x4f7/0x970
 worker_thread+0x8f/0x620
 kthread+0x17f/0x1c0
 ret_from_fork+0x2c/0x50

Freed by task 771:
 kasan_save_stack+0x33/0x60
 kasan_set_track+0x25/0x30
 kasan_save_free_info+0x2e/0x50
 ____kasan_slab_free+0x169/0x1c0
 slab_free_freelist_hook+0x9e/0x1c0
 __kmem_cache_free+0xc0/0x310
 hci_chan_list_flush+0x46/0x90 [bluetooth]
 hci_conn_cleanup+0x7d/0x330 [bluetooth]
 hci_cs_disconnect+0x35d/0x530 [bluetooth]
 hci_cmd_status_evt+0xef/0x2b0 [bluetooth]
 hci_event_packet+0x38d/0x800 [bluetooth]
 hci_rx_work+0x287/0xb20 [bluetooth]
 process_one_work+0x4f7/0x970
 worker_thread+0x8f/0x620
 kthread+0x17f/0x1c0
 ret_from_fork+0x2c/0x50
==================================================================

Fixes: b8d29052 ("Bluetooth: clean up connection in hci_cs_disconnect")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

hci_update_accept_list_sync iterates over hdev->pend_le_conns and
hdev->pend_le_reports, and waits for controller events in the loop body,
without holding hdev lock.

Meanwhile, these lists and the items may be modified e.g. by
le_scan_cleanup. This can invalidate the list cursor or any other item
in the list, resulting to invalid behavior (eg use-after-free).

Use RCU for the hci_conn_params action lists. Since the loop bodies in
hci_sync block and we cannot use RCU or hdev->lock for the whole loop,
copy list items first and then iterate on the copy. Only the flags field
is written from elsewhere, so READ_ONCE/WRITE_ONCE should guarantee we
read valid values.

Free params everywhere with hci_conn_params_free so the cleanup is
guaranteed to be done properly.

This fixes the following, which can be triggered e.g. by BlueZ new
mgmt-tester case "Add + Remove Device Nowait - Success", or by changing
hci_le_set_cig_params to always return false, and running iso-tester:

==================================================================
BUG: KASAN: slab-use-after-free in hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841)
Read of size 8 at addr ffff888001265018 by task kworker/u3:0/32

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
<TASK>
dump_stack_lvl (./arch/x86/include/asm/irqflags.h:134 lib/dump_stack.c:107)
print_report (mm/kasan/report.c:320 mm/kasan/report.c:430)
? __virt_addr_valid (./include/linux/mmzone.h:1915 ./include/linux/mmzone.h:2011 arch/x86/mm/physaddr.c:65)
? hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841)
kasan_report (mm/kasan/report.c:538)
? hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841)
hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841)
? __pfx_hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2780)
? mutex_lock (kernel/locking/mutex.c:282)
? __pfx_mutex_lock (kernel/locking/mutex.c:282)
? __pfx_mutex_unlock (kernel/locking/mutex.c:538)
? __pfx_update_passive_scan_sync (net/bluetooth/hci_sync.c:2861)
hci_cmd_sync_work (net/bluetooth/hci_sync.c:306)
process_one_work (./arch/x86/include/asm/preempt.h:27 kernel/workqueue.c:2399)
worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2538)
? __pfx_worker_thread (kernel/workqueue.c:2480)
kthread (kernel/kthread.c:376)
? __pfx_kthread (kernel/kthread.c:331)
ret_from_fork (arch/x86/entry/entry_64.S:314)
</TASK>

Allocated by task 31:
kasan_save_stack (mm/kasan/common.c:46)
kasan_set_track (mm/kasan/common.c:52)
__kasan_kmalloc (mm/kasan/common.c:374 mm/kasan/common.c:383)
hci_conn_params_add (./include/linux/slab.h:580 ./include/linux/slab.h:720 net/bluetooth/hci_core.c:2277)
hci_connect_le_scan (net/bluetooth/hci_conn.c:1419 net/bluetooth/hci_conn.c:1589)
hci_connect_cis (net/bluetooth/hci_conn.c:2266)
iso_connect_cis (net/bluetooth/iso.c:390)
iso_sock_connect (net/bluetooth/iso.c:899)
__sys_connect (net/socket.c:2003 net/socket.c:2020)
__x64_sys_connect (net/socket.c:2027)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)

Freed by task 15:
kasan_save_stack (mm/kasan/common.c:46)
kasan_set_track (mm/kasan/common.c:52)
kasan_save_free_info (mm/kasan/generic.c:523)
__kasan_slab_free (mm/kasan/common.c:238 mm/kasan/common.c:200 mm/kasan/common.c:244)
__kmem_cache_free (mm/slub.c:1807 mm/slub.c:3787 mm/slub.c:3800)
hci_conn_params_del (net/bluetooth/hci_core.c:2323)
le_scan_cleanup (net/bluetooth/hci_conn.c:202)
process_one_work (./arch/x86/include/asm/preempt.h:27 kernel/workqueue.c:2399)
worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2538)
kthread (kernel/kthread.c:376)
ret_from_fork (arch/x86/entry/entry_64.S:314)
==================================================================

Fixes: e8907f76 ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 3")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Skip bound chain when flushing table rules, the rule that owns this
chain releases these objects.

Otherwise, the following warning is triggered:

  WARNING: CPU: 2 PID: 1217 at net/netfilter/nf_tables_api.c:2013 nf_tables_chain_destroy+0x1f7/0x210 [nf_tables]
  CPU: 2 PID: 1217 Comm: chain-flush Not tainted 6.1.39 #1
  RIP: 0010:nf_tables_chain_destroy+0x1f7/0x210 [nf_tables]

Fixes: d0e2c7de ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Reported-by: Kevin Rich <kevinrich1337@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

Skip bound chain from netns release path, the rule that owns this chain
releases these objects.

Fixes: d0e2c7de ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

end key should be equal to start unless NFT_SET_EXT_KEY_END is present.

Its possible to add elements that only have a start key
("{ 1.0.0.0 . 2.0.0.0 }") without an internval end.

Insertion treats this via:

if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END))
   end = (const u8 *)nft_set_ext_key_end(ext)->data;
else
   end = start;

but removal side always uses nft_set_ext_key_end().
This is wrong and leads to garbage remaining in the set after removal
next lookup/insert attempt will give:

BUG: KASAN: slab-use-after-free in pipapo_get+0x8eb/0xb90
Read of size 1 at addr ffff888100d50586 by task nft-pipapo_uaf_/1399
Call Trace:
 kasan_report+0x105/0x140
 pipapo_get+0x8eb/0xb90
 nft_pipapo_insert+0x1dc/0x1710
 nf_tables_newsetelem+0x31f5/0x4e00
 ..

Fixes: 3c4287f6 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Reported-by: lonial con <kongln9170@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>

Can be called via nft set element list iteration, which may acquire
rcu and/or bh read lock (depends on set type).

BUG: sleeping function called from invalid context at net/netfilter/nf_tables_api.c:3353
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1232, name: nft
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
2 locks held by nft/1232:
 #0: ffff8881180e3ea8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid
 #1: ffffffff83f5f540 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire
Call Trace:
 nft_chain_validate
 nft_lookup_validate_setelem
 nft_pipapo_walk
 nft_lookup_validate
 nft_chain_validate
 nft_immediate_validate
 nft_chain_validate
 nf_tables_validate
 nf_tables_abort

No choice but to move it to nf_tables_validate().

Fixes: 81ea0106 ("netfilter: nf_tables: add rescheduling points during loop detection walks")
Signed-off-by: Florian Westphal <fw@strlen.de>

On some platforms there is a padding hole in the nft_verdict
structure, between the verdict code and the chain pointer.

On element insertion, if the new element clashes with an existing one and
NLM_F_EXCL flag isn't set, we want to ignore the -EEXIST error as long as
the data associated with duplicated element is the same as the existing
one.  The data equality check uses memcmp.

For normal data (NFT_DATA_VALUE) this works fine, but for NFT_DATA_VERDICT
padding area leads to spurious failure even if the verdict data is the
same.

This then makes the insertion fail with 'already exists' error, even
though the new "key : data" matches an existing entry and userspace
told the kernel that it doesn't want to receive an error indication.

Fixes: c016c7e4 ("netfilter: nf_tables: honor NLM_F_EXCL flag in set element insertion")
Signed-off-by: Florian Westphal <fw@strlen.de>

Kuniyuki Iwashima says:

====================
net: Support STP on bridge in non-root netns.

Currently, STP does not work in non-root netns as llc_rcv() drops
packets from non-root netns.

This series fixes it by making some protocol handlers netns-aware,
which are called from llc_rcv() as follows:

  llc_rcv()
  |
  |- sap->rcv_func : registered by llc_sap_open()
  |
  |  * functions : regsitered by register_8022_client()
  |    -> No in-kernel user call register_8022_client()
  |
  |  * snap_rcv()
  |    |
  |    `- proto->rcvfunc() : registered by register_snap_client()
  |
  |       * aarp_rcv()  : drop packets from non-root netns
  |       * atalk_rcv() : drop packets from non-root netns
  |
  |  * stp_pdu_rcv()
  |    |
  |    `- garp_protos[]->rcv() : registered by stp_proto_register()
  |
  |       * garp_pdu_rcv() : netns-aware
  |       * br_stp_rcv()   : netns-aware
  |
  |- llc_type_handlers[llc_pdu_type(skb) - 1]
  |
  |  * llc_sap_handler()  : NOT netns-aware (Patch 1)
  |  * llc_conn_handler() : NOT netns-aware (Patch 2)
  |
  `- llc_station_handler

     * llc_station_rcv() : netns-aware

Patch 1 & 2 convert not-netns-aware functions and Patch 3 remove the
netns restriction in llc_rcv().

Note this series does not namespacify AF_LLC so that these patches
can be backported to stable without conflicts (at least to 4.14.y).

Another series that adds netns support for AF_LLC will be targeted
to net-next later.
====================

Link: https://lore.kernel.org/r/20230718174152.57408-1-kuniyu@amazon.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

This reverts commit 56a16035.

Since the previous commit, STP works on bridge in netns.

  # unshare -n
  # ip link add br0 type bridge
  # ip link add veth0 type veth peer name veth1

  # ip link set veth0 master br0 up
  [   50.558135] br0: port 1(veth0) entered blocking state
  [   50.558366] br0: port 1(veth0) entered disabled state
  [   50.558798] veth0: entered allmulticast mode
  [   50.564401] veth0: entered promiscuous mode

  # ip link set veth1 master br0 up
  [   54.215487] br0: port 2(veth1) entered blocking state
  [   54.215657] br0: port 2(veth1) entered disabled state
  [   54.215848] veth1: entered allmulticast mode
  [   54.219577] veth1: entered promiscuous mode

  # ip link set br0 type bridge stp_state 1
  # ip link set br0 up
  [   61.960726] br0: port 2(veth1) entered blocking state
  [   61.961097] br0: port 2(veth1) entered listening state
  [   61.961495] br0: port 1(veth0) entered blocking state
  [   61.961653] br0: port 1(veth0) entered listening state
  [   63.998835] br0: port 2(veth1) entered blocking state
  [   77.437113] br0: port 1(veth0) entered learning state
  [   86.653501] br0: received packet on veth0 with own address as source address (addr:6e:0f:e7:6f:5f:5f, vlan:0)
  [   92.797095] br0: port 1(veth0) entered forwarding state
  [   92.797398] br0: topology change detected, propagating

Let's remove the warning.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Now these upper layer protocol handlers can be called from llc_rcv()
as sap->rcv_func(), which is registered by llc_sap_open().

  * function which is passed to register_8022_client()
    -> no in-kernel user calls register_8022_client().

  * snap_rcv()
    `- proto->rcvfunc() : registered by register_snap_client()
       -> aarp_rcv() and atalk_rcv() drop packets from non-root netns

  * stp_pdu_rcv()
    `- garp_protos[]->rcv() : registered by stp_proto_register()
       -> garp_pdu_rcv() and br_stp_rcv() are netns-aware

So, we can safely remove the netns restriction in llc_rcv().

Fixes: e730c155 ("[NET]: Make packet reception network namespace safe")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

We will remove this restriction in llc_rcv() in the following patch,
which means that the protocol handler must be aware of netns.

        if (!net_eq(dev_net(dev), &init_net))
                goto drop;

llc_rcv() fetches llc_type_handlers[llc_pdu_type(skb) - 1] and calls it
if not NULL.

If the PDU type is LLC_DEST_CONN, llc_conn_handler() is called to pass
skb to corresponding sockets.  Then, we must look up a proper socket in
the same netns with skb->dev.

llc_conn_handler() calls __llc_lookup() to look up a established or
litening socket by __llc_lookup_established() and llc_lookup_listener().

Both functions iterate on a list and call llc_estab_match() or
llc_listener_match() to check if the socket is the correct destination.
However, these functions do not check netns.

Also, bind() and connect() call llc_establish_connection(), which
finally calls __llc_lookup_established(), to check if there is a
conflicting socket.

Let's test netns in llc_estab_match() and llc_listener_match().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

We will remove this restriction in llc_rcv() soon, which means that the
protocol handler must be aware of netns.

	if (!net_eq(dev_net(dev), &init_net))
		goto drop;

llc_rcv() fetches llc_type_handlers[llc_pdu_type(skb) - 1] and calls it
if not NULL.

If the PDU type is LLC_DEST_SAP, llc_sap_handler() is called to pass skb
to corresponding sockets.  Then, we must look up a proper socket in the
same netns with skb->dev.

If the destination is a multicast address, llc_sap_handler() calls
llc_sap_mcast().  It calculates a hash based on DSAP and skb->dev->ifindex,
iterates on a socket list, and calls llc_mcast_match() to check if the
socket is the correct destination.  Then, llc_mcast_match() checks if
skb->dev matches with llc_sk(sk)->dev.  So, we need not check netns here.

OTOH, if the destination is a unicast address, llc_sap_handler() calls
llc_lookup_dgram() to look up a socket, but it does not check the netns.

Therefore, we need to add netns check in llc_lookup_dgram().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

entries and bind debugfs files would display wrong data on NETSYS_V2 and
later because instead of using mtk_get_ib1_pkt_type the driver would use
MTK_FOE_IB1_PACKET_TYPE which corresponds to NETSYS_V1(.x) SoCs.
Use mtk_get_ib1_pkt_type so entries and bind records display correctly.

Fixes: 03a3180e ("net: ethernet: mtk_eth_soc: introduce flow offloading support for mt7986")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/c0ae03d0182f4d27b874cbdf0059bc972c317f3c.1689727134.git.daniel@makrotopia.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Heiner Kallweit says:

====================
r8169: revert two changes that caused regressions

This reverts two changes that caused regressions.
====================

Link: https://lore.kernel.org/r/ddadceae-19c9-81b8-47b5-a4ff85e2563a@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This reverts commit e1ed3e4d.

Turned out the change causes a performance regression.

Link: https://lore.kernel.org/netdev/20230713124914.GA12924@green245/T/
Cc: stable@vger.kernel.org
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/055c6bc2-74fa-8c67-9897-3f658abb5ae7@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

r8169: revert 2ab19de6 ("r8169: remove ASPM restrictions now that ASPM is disabled during NAPI poll")

There have been reports that on a number of systems this change breaks
network connectivity. Therefore effectively revert it. Mainly affected
seem to be systems where BIOS denies ASPM access to OS.
Due to later changes we can't do a direct revert.

Fixes: 2ab19de6 ("r8169: remove ASPM restrictions now that ASPM is disabled during NAPI poll")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/netdev/e47bac0d-e802-65e1-b311-6acb26d5cf10@freenet.de/T/
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217596Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/57f13ec0-b216-d5d8-363d-5b05528ec5fb@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This reverts commit 3f4ca5fa.

Commit 3f4ca5fa ("tcp: avoid the lookup process failing to get sk in
ehash table") reversed the order in how a socket is inserted into ehash
to fix an issue that ehash-lookup could fail when reqsk/full sk/twsk are
swapped.  However, it introduced another lookup failure.

The full socket in ehash is allocated from a slab with SLAB_TYPESAFE_BY_RCU
and does not have SOCK_RCU_FREE, so the socket could be reused even while
it is being referenced on another CPU doing RCU lookup.

Let's say a socket is reused and inserted into the same hash bucket during
lookup.  After the blamed commit, a new socket is inserted at the end of
the list.  If that happens, we will skip sockets placed after the previous
position of the reused socket, resulting in ehash lookup failure.

As described in Documentation/RCU/rculist_nulls.rst, we should insert a
new socket at the head of the list to avoid such an issue.

This issue, the swap-lookup-failure, and another variant reported in [0]
can all be handled properly by adding a locked ehash lookup suggested by
Eric Dumazet [1].

However, this issue could occur for every packet, thus more likely than
the other two races, so let's revert the change for now.

Link: https://lore.kernel.org/netdev/20230606064306.9192-1-duanmuquan@baidu.com/ [0]
Link: https://lore.kernel.org/netdev/CANn89iK8snOz8TYOhhwfimC7ykYA78GA3Nyv8x06SZYa1nKdyA@mail.gmail.com/ [1]
Fixes: 3f4ca5fa ("tcp: avoid the lookup process failing to get sk in ehash table")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230717215918.15723-1-kuniyu@amazon.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Alexei Starovoitov says:

====================
pull-request: bpf 2023-07-19

We've added 4 non-merge commits during the last 1 day(s) which contain
a total of 3 files changed, 55 insertions(+), 10 deletions(-).

The main changes are:

1) Fix stack depth check in presence of async callbacks,
   from Kumar Kartikeya Dwivedi.

2) Fix BTI type used for freplace attached functions,
   from Alexander Duyck.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, arm64: Fix BTI type used for freplace attached functions
  selftests/bpf: Add more tests for check_max_stack_depth bug
  bpf: Repeat check_max_stack_depth for async callbacks
  bpf: Fix subprog idx logic in check_max_stack_depth
====================

Link: https://lore.kernel.org/r/20230719174502.74023-1-alexei.starovoitov@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>