<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/netlink, branch v6.5.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2023-06-27T16:45:22+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-06-27T16:45:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3674fbf0451df0395f9fa18df3122927006a3829'/>
<id>3674fbf0451df0395f9fa18df3122927006a3829</id>
<content type='text'>
Merge in late fixes to prepare for the 6.5 net-next PR.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge in late fixes to prepare for the 6.5 net-next PR.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netlink: Add __sock_i_ino() for __netlink_diag_dump().</title>
<updated>2023-06-27T16:37:41+00:00</updated>
<author>
<name>Kuniyuki Iwashima</name>
<email>kuniyu@amazon.com</email>
</author>
<published>2023-06-26T16:43:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=25a9c8a4431c364f97f75558cb346d2ad3f53fbb'/>
<id>25a9c8a4431c364f97f75558cb346d2ad3f53fbb</id>
<content type='text'>
syzbot reported a warning in __local_bh_enable_ip(). [0]

Commit 8d61f926d420 ("netlink: fix potential deadlock in
netlink_set_err()") converted read_lock(&amp;nl_table_lock) to
read_lock_irqsave() in __netlink_diag_dump() to prevent a deadlock.

However, __netlink_diag_dump() calls sock_i_ino() that uses
read_lock_bh() and read_unlock_bh().  If CONFIG_TRACE_IRQFLAGS=y,
read_unlock_bh() finally enables IRQ even though it should stay
disabled until the following read_unlock_irqrestore().

Using read_lock() in sock_i_ino() would trigger a lockdep splat
in another place that was fixed in commit f064af1e500a ("net: fix
a lockdep splat"), so let's add __sock_i_ino() that would be safe
to use under BH disabled.

[0]:
WARNING: CPU: 0 PID: 5012 at kernel/softirq.c:376 __local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376
Modules linked in:
CPU: 0 PID: 5012 Comm: syz-executor487 Not tainted 6.4.0-rc7-syzkaller-00202-g6f68fc395f49 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:__local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376
Code: 45 bf 01 00 00 00 e8 91 5b 0a 00 e8 3c 15 3d 00 fb 65 8b 05 ec e9 b5 7e 85 c0 74 58 5b 5d c3 65 8b 05 b2 b6 b4 7e 85 c0 75 a2 &lt;0f&gt; 0b eb 9e e8 89 15 3d 00 eb 9f 48 89 ef e8 6f 49 18 00 eb a8 0f
RSP: 0018:ffffc90003a1f3d0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000201 RCX: 1ffffffff1cf5996
RDX: 0000000000000000 RSI: 0000000000000201 RDI: ffffffff8805c6f3
RBP: ffffffff8805c6f3 R08: 0000000000000001 R09: ffff8880152b03a3
R10: ffffed1002a56074 R11: 0000000000000005 R12: 00000000000073e4
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS:  0000555556726300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000045ad50 CR3: 000000007c646000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 &lt;TASK&gt;
 sock_i_ino+0x83/0xa0 net/core/sock.c:2559
 __netlink_diag_dump+0x45c/0x790 net/netlink/diag.c:171
 netlink_diag_dump+0xd6/0x230 net/netlink/diag.c:207
 netlink_dump+0x570/0xc50 net/netlink/af_netlink.c:2269
 __netlink_dump_start+0x64b/0x910 net/netlink/af_netlink.c:2374
 netlink_dump_start include/linux/netlink.h:329 [inline]
 netlink_diag_handler_dump+0x1ae/0x250 net/netlink/diag.c:238
 __sock_diag_cmd net/core/sock_diag.c:238 [inline]
 sock_diag_rcv_msg+0x31e/0x440 net/core/sock_diag.c:269
 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2547
 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0xde/0x190 net/socket.c:747
 ____sys_sendmsg+0x71c/0x900 net/socket.c:2503
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2557
 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2586
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5303aaabb9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc7506e548 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5303aaabb9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00007f5303a6ed60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5303a6edf0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 &lt;/TASK&gt;

Fixes: 8d61f926d420 ("netlink: fix potential deadlock in netlink_set_err()")
Reported-by: syzbot+5da61cf6a9bc1902d422@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=5da61cf6a9bc1902d422
Suggested-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/20230626164313.52528-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
syzbot reported a warning in __local_bh_enable_ip(). [0]

Commit 8d61f926d420 ("netlink: fix potential deadlock in
netlink_set_err()") converted read_lock(&amp;nl_table_lock) to
read_lock_irqsave() in __netlink_diag_dump() to prevent a deadlock.

However, __netlink_diag_dump() calls sock_i_ino() that uses
read_lock_bh() and read_unlock_bh().  If CONFIG_TRACE_IRQFLAGS=y,
read_unlock_bh() finally enables IRQ even though it should stay
disabled until the following read_unlock_irqrestore().

Using read_lock() in sock_i_ino() would trigger a lockdep splat
in another place that was fixed in commit f064af1e500a ("net: fix
a lockdep splat"), so let's add __sock_i_ino() that would be safe
to use under BH disabled.

[0]:
WARNING: CPU: 0 PID: 5012 at kernel/softirq.c:376 __local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376
Modules linked in:
CPU: 0 PID: 5012 Comm: syz-executor487 Not tainted 6.4.0-rc7-syzkaller-00202-g6f68fc395f49 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:__local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376
Code: 45 bf 01 00 00 00 e8 91 5b 0a 00 e8 3c 15 3d 00 fb 65 8b 05 ec e9 b5 7e 85 c0 74 58 5b 5d c3 65 8b 05 b2 b6 b4 7e 85 c0 75 a2 &lt;0f&gt; 0b eb 9e e8 89 15 3d 00 eb 9f 48 89 ef e8 6f 49 18 00 eb a8 0f
RSP: 0018:ffffc90003a1f3d0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000201 RCX: 1ffffffff1cf5996
RDX: 0000000000000000 RSI: 0000000000000201 RDI: ffffffff8805c6f3
RBP: ffffffff8805c6f3 R08: 0000000000000001 R09: ffff8880152b03a3
R10: ffffed1002a56074 R11: 0000000000000005 R12: 00000000000073e4
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS:  0000555556726300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000045ad50 CR3: 000000007c646000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 &lt;TASK&gt;
 sock_i_ino+0x83/0xa0 net/core/sock.c:2559
 __netlink_diag_dump+0x45c/0x790 net/netlink/diag.c:171
 netlink_diag_dump+0xd6/0x230 net/netlink/diag.c:207
 netlink_dump+0x570/0xc50 net/netlink/af_netlink.c:2269
 __netlink_dump_start+0x64b/0x910 net/netlink/af_netlink.c:2374
 netlink_dump_start include/linux/netlink.h:329 [inline]
 netlink_diag_handler_dump+0x1ae/0x250 net/netlink/diag.c:238
 __sock_diag_cmd net/core/sock_diag.c:238 [inline]
 sock_diag_rcv_msg+0x31e/0x440 net/core/sock_diag.c:269
 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2547
 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0xde/0x190 net/socket.c:747
 ____sys_sendmsg+0x71c/0x900 net/socket.c:2503
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2557
 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2586
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5303aaabb9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc7506e548 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5303aaabb9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00007f5303a6ed60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5303a6edf0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 &lt;/TASK&gt;

Fixes: 8d61f926d420 ("netlink: fix potential deadlock in netlink_set_err()")
Reported-by: syzbot+5da61cf6a9bc1902d422@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=5da61cf6a9bc1902d422
Suggested-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/20230626164313.52528-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sock: Remove -&gt;sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)</title>
<updated>2023-06-24T22:50:13+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2023-06-23T22:55:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dc97391e661009eab46783030d2404c9b6e6f2e7'/>
<id>dc97391e661009eab46783030d2404c9b6e6f2e7</id>
<content type='text'>
Remove -&gt;sendpage() and -&gt;sendpage_locked().  sendmsg() with
MSG_SPLICE_PAGES should be used instead.  This allows multiple pages and
multipage folios to be passed through.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt; # for net/can
cc: Jens Axboe &lt;axboe@kernel.dk&gt;
cc: Matthew Wilcox &lt;willy@infradead.org&gt;
cc: linux-afs@lists.infradead.org
cc: mptcp@lists.linux.dev
cc: rds-devel@oss.oracle.com
cc: tipc-discussion@lists.sourceforge.net
cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove -&gt;sendpage() and -&gt;sendpage_locked().  sendmsg() with
MSG_SPLICE_PAGES should be used instead.  This allows multiple pages and
multipage folios to be passed through.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt; # for net/can
cc: Jens Axboe &lt;axboe@kernel.dk&gt;
cc: Matthew Wilcox &lt;willy@infradead.org&gt;
cc: linux-afs@lists.infradead.org
cc: mptcp@lists.linux.dev
cc: rds-devel@oss.oracle.com
cc: tipc-discussion@lists.sourceforge.net
cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netlink: fix potential deadlock in netlink_set_err()</title>
<updated>2023-06-23T02:35:06+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2023-06-21T15:43:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8d61f926d42045961e6b65191c09e3678d86a9cf'/>
<id>8d61f926d42045961e6b65191c09e3678d86a9cf</id>
<content type='text'>
syzbot reported a possible deadlock in netlink_set_err() [1]

A similar issue was fixed in commit 1d482e666b8e ("netlink: disable IRQs
for netlink_lock_table()") in netlink_lock_table()

This patch adds IRQ safety to netlink_set_err() and __netlink_diag_dump()
which were not covered by cited commit.

[1]

WARNING: possible irq lock inversion dependency detected
6.4.0-rc6-syzkaller-00240-g4e9f0ec38852 #0 Not tainted

syz-executor.2/23011 just changed the state of lock:
ffffffff8e1a7a58 (nl_table_lock){.+.?}-{2:2}, at: netlink_set_err+0x2e/0x3a0 net/netlink/af_netlink.c:1612
but this lock was taken by another, SOFTIRQ-safe lock in the past:
 (&amp;local-&gt;queue_stop_reason_lock){..-.}-{2:2}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(nl_table_lock);
                               local_irq_disable();
                               lock(&amp;local-&gt;queue_stop_reason_lock);
                               lock(nl_table_lock);
  &lt;Interrupt&gt;
    lock(&amp;local-&gt;queue_stop_reason_lock);

 *** DEADLOCK ***

Fixes: 1d482e666b8e ("netlink: disable IRQs for netlink_lock_table()")
Reported-by: syzbot+a7d200a347f912723e5c@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=a7d200a347f912723e5c
Link: https://lore.kernel.org/netdev/000000000000e38d1605fea5747e@google.com/T/#u
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Johannes Berg &lt;johannes.berg@intel.com&gt;
Link: https://lore.kernel.org/r/20230621154337.1668594-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
syzbot reported a possible deadlock in netlink_set_err() [1]

A similar issue was fixed in commit 1d482e666b8e ("netlink: disable IRQs
for netlink_lock_table()") in netlink_lock_table()

This patch adds IRQ safety to netlink_set_err() and __netlink_diag_dump()
which were not covered by cited commit.

[1]

WARNING: possible irq lock inversion dependency detected
6.4.0-rc6-syzkaller-00240-g4e9f0ec38852 #0 Not tainted

syz-executor.2/23011 just changed the state of lock:
ffffffff8e1a7a58 (nl_table_lock){.+.?}-{2:2}, at: netlink_set_err+0x2e/0x3a0 net/netlink/af_netlink.c:1612
but this lock was taken by another, SOFTIRQ-safe lock in the past:
 (&amp;local-&gt;queue_stop_reason_lock){..-.}-{2:2}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(nl_table_lock);
                               local_irq_disable();
                               lock(&amp;local-&gt;queue_stop_reason_lock);
                               lock(nl_table_lock);
  &lt;Interrupt&gt;
    lock(&amp;local-&gt;queue_stop_reason_lock);

 *** DEADLOCK ***

Fixes: 1d482e666b8e ("netlink: disable IRQs for netlink_lock_table()")
Reported-by: syzbot+a7d200a347f912723e5c@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=a7d200a347f912723e5c
Link: https://lore.kernel.org/netdev/000000000000e38d1605fea5747e@google.com/T/#u
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Johannes Berg &lt;johannes.berg@intel.com&gt;
Link: https://lore.kernel.org/r/20230621154337.1668594-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netlink: support extack in dump -&gt;start()</title>
<updated>2023-06-12T10:32:44+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-06-09T21:53:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5ab8c41cef30d8b6160a80b69d2eb39d570491ac'/>
<id>5ab8c41cef30d8b6160a80b69d2eb39d570491ac</id>
<content type='text'>
Commit 4a19edb60d02 ("netlink: Pass extack to dump handlers")
added extack support to netlink dumps. It was focused on rtnl
and since rtnl does not use -&gt;start(), -&gt;done() callbacks
it ignored those. Genetlink on the other hand uses -&gt;start()
extensively, for parsing and input validation.

Pass the extact in via struct netlink_dump_control and link
it to cb for the time of -&gt;start(). Both struct netlink_dump_control
and extack itself live on the stack so we can't keep the same
extack for the duration of the dump. This means that the extack
visible in -&gt;start() and each -&gt;dump() callbacks will be different.
Corner cases like reporting a warning message in DONE across dump
calls are still not supported.

We could put the extack (for dumps) in the socket struct,
but layering makes it slightly awkward (extack pointer is decided
before the DO / DUMP split).

The genetlink dump error extacks are now surfaced:

  $ cli.py --spec netlink/specs/ethtool.yaml --dump channels-get
  lib.ynl.NlError: Netlink error: Invalid argument
  nl_len = 64 (48) nl_flags = 0x300 nl_type = 2
	error: -22	extack: {'msg': 'request header missing'}

Previously extack was missing:

  $ cli.py --spec netlink/specs/ethtool.yaml --dump channels-get
  lib.ynl.NlError: Netlink error: Invalid argument
  nl_len = 36 (20) nl_flags = 0x100 nl_type = 2
	error: -22

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 4a19edb60d02 ("netlink: Pass extack to dump handlers")
added extack support to netlink dumps. It was focused on rtnl
and since rtnl does not use -&gt;start(), -&gt;done() callbacks
it ignored those. Genetlink on the other hand uses -&gt;start()
extensively, for parsing and input validation.

Pass the extact in via struct netlink_dump_control and link
it to cb for the time of -&gt;start(). Both struct netlink_dump_control
and extack itself live on the stack so we can't keep the same
extack for the duration of the dump. This means that the extack
visible in -&gt;start() and each -&gt;dump() callbacks will be different.
Corner cases like reporting a warning message in DONE across dump
calls are still not supported.

We could put the extack (for dumps) in the socket struct,
but layering makes it slightly awkward (extack pointer is decided
before the DO / DUMP split).

The genetlink dump error extacks are now surfaced:

  $ cli.py --spec netlink/specs/ethtool.yaml --dump channels-get
  lib.ynl.NlError: Netlink error: Invalid argument
  nl_len = 64 (48) nl_flags = 0x300 nl_type = 2
	error: -22	extack: {'msg': 'request header missing'}

Previously extack was missing:

  $ cli.py --spec netlink/specs/ethtool.yaml --dump channels-get
  lib.ynl.NlError: Netlink error: Invalid argument
  nl_len = 36 (20) nl_flags = 0x100 nl_type = 2
	error: -22

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/netlink: fix NETLINK_LIST_MEMBERSHIPS length report</title>
<updated>2023-05-31T07:02:24+00:00</updated>
<author>
<name>Pedro Tammela</name>
<email>pctammela@mojatatu.com</email>
</author>
<published>2023-05-29T15:33:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f4e4534850a9d18c250a93f8d7fbb51310828110'/>
<id>f4e4534850a9d18c250a93f8d7fbb51310828110</id>
<content type='text'>
The current code for the length calculation wrongly truncates the reported
length of the groups array, causing an under report of the subscribed
groups. To fix this, use 'BITS_TO_BYTES()' which rounds up the
division by 8.

Fixes: b42be38b2778 ("netlink: add API to retrieve all group memberships")
Signed-off-by: Pedro Tammela &lt;pctammela@mojatatu.com&gt;
Reviewed-by: Simon Horman &lt;simon.horman@corigine.com&gt;
Link: https://lore.kernel.org/r/20230529153335.389815-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The current code for the length calculation wrongly truncates the reported
length of the groups array, causing an under report of the subscribed
groups. To fix this, use 'BITS_TO_BYTES()' which rounds up the
division by 8.

Fixes: b42be38b2778 ("netlink: add API to retrieve all group memberships")
Signed-off-by: Pedro Tammela &lt;pctammela@mojatatu.com&gt;
Reviewed-by: Simon Horman &lt;simon.horman@corigine.com&gt;
Link: https://lore.kernel.org/r/20230529153335.389815-1-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netlink: annotate accesses to nlk-&gt;cb_running</title>
<updated>2023-05-10T08:28:38+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2023-05-09T16:56:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a939d14919b799e6fff8a9c80296ca229ba2f8a4'/>
<id>a939d14919b799e6fff8a9c80296ca229ba2f8a4</id>
<content type='text'>
Both netlink_recvmsg() and netlink_native_seq_show() read
nlk-&gt;cb_running locklessly. Use READ_ONCE() there.

Add corresponding WRITE_ONCE() to netlink_dump() and
__netlink_dump_start()

syzbot reported:
BUG: KCSAN: data-race in __netlink_dump_start / netlink_recvmsg

write to 0xffff88813ea4db59 of 1 bytes by task 28219 on cpu 0:
__netlink_dump_start+0x3af/0x4d0 net/netlink/af_netlink.c:2399
netlink_dump_start include/linux/netlink.h:308 [inline]
rtnetlink_rcv_msg+0x70f/0x8c0 net/core/rtnetlink.c:6130
netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2577
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6192
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1942
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
sock_write_iter+0x1aa/0x230 net/socket.c:1138
call_write_iter include/linux/fs.h:1851 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x463/0x760 fs/read_write.c:584
ksys_write+0xeb/0x1a0 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__x64_sys_write+0x42/0x50 fs/read_write.c:646
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88813ea4db59 of 1 bytes by task 28222 on cpu 1:
netlink_recvmsg+0x3b4/0x730 net/netlink/af_netlink.c:2022
sock_recvmsg_nosec+0x4c/0x80 net/socket.c:1017
____sys_recvmsg+0x2db/0x310 net/socket.c:2718
___sys_recvmsg net/socket.c:2762 [inline]
do_recvmmsg+0x2e5/0x710 net/socket.c:2856
__sys_recvmmsg net/socket.c:2935 [inline]
__do_sys_recvmmsg net/socket.c:2958 [inline]
__se_sys_recvmmsg net/socket.c:2951 [inline]
__x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00 -&gt; 0x01

Fixes: 16b304f3404f ("netlink: Eliminate kmalloc in netlink dump operation.")
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Both netlink_recvmsg() and netlink_native_seq_show() read
nlk-&gt;cb_running locklessly. Use READ_ONCE() there.

Add corresponding WRITE_ONCE() to netlink_dump() and
__netlink_dump_start()

syzbot reported:
BUG: KCSAN: data-race in __netlink_dump_start / netlink_recvmsg

write to 0xffff88813ea4db59 of 1 bytes by task 28219 on cpu 0:
__netlink_dump_start+0x3af/0x4d0 net/netlink/af_netlink.c:2399
netlink_dump_start include/linux/netlink.h:308 [inline]
rtnetlink_rcv_msg+0x70f/0x8c0 net/core/rtnetlink.c:6130
netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2577
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6192
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1942
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
sock_write_iter+0x1aa/0x230 net/socket.c:1138
call_write_iter include/linux/fs.h:1851 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x463/0x760 fs/read_write.c:584
ksys_write+0xeb/0x1a0 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__x64_sys_write+0x42/0x50 fs/read_write.c:646
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88813ea4db59 of 1 bytes by task 28222 on cpu 1:
netlink_recvmsg+0x3b4/0x730 net/netlink/af_netlink.c:2022
sock_recvmsg_nosec+0x4c/0x80 net/socket.c:1017
____sys_recvmsg+0x2db/0x310 net/socket.c:2718
___sys_recvmsg net/socket.c:2762 [inline]
do_recvmmsg+0x2e5/0x710 net/socket.c:2856
__sys_recvmmsg net/socket.c:2935 [inline]
__do_sys_recvmmsg net/socket.c:2958 [inline]
__se_sys_recvmmsg net/socket.c:2951 [inline]
__x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00 -&gt; 0x01

Fixes: 16b304f3404f ("netlink: Eliminate kmalloc in netlink dump operation.")
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2023-04-26T08:17:46+00:00</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2023-04-26T08:17:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c248b27cfc0a8a5fee93e000d47e659bca335d0f'/>
<id>c248b27cfc0a8a5fee93e000d47e659bca335d0f</id>
<content type='text'>
No conflicts.

Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No conflicts.

Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netlink: Use copy_to_user() for optval in netlink_getsockopt().</title>
<updated>2023-04-25T01:05:36+00:00</updated>
<author>
<name>Kuniyuki Iwashima</name>
<email>kuniyu@amazon.com</email>
</author>
<published>2023-04-21T18:52:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d913d32cc2707e9cd24fe6fa6d7d470e9c728980'/>
<id>d913d32cc2707e9cd24fe6fa6d7d470e9c728980</id>
<content type='text'>
Brad Spencer provided a detailed report [0] that when calling getsockopt()
for AF_NETLINK, some SOL_NETLINK options set only 1 byte even though such
options require at least sizeof(int) as length.

The options return a flag value that fits into 1 byte, but such behaviour
confuses users who do not initialise the variable before calling
getsockopt() and do not strictly check the returned value as char.

Currently, netlink_getsockopt() uses put_user() to copy data to optlen and
optval, but put_user() casts the data based on the pointer, char *optval.
As a result, only 1 byte is set to optval.

To avoid this behaviour, we need to use copy_to_user() or cast optval for
put_user().

Note that this changes the behaviour on big-endian systems, but we document
that the size of optval is int in the man page.

  $ man 7 netlink
  ...
  Socket options
       To set or get a netlink socket option, call getsockopt(2) to read
       or setsockopt(2) to write the option with the option level argument
       set to SOL_NETLINK.  Unless otherwise noted, optval is a pointer to
       an int.

Fixes: 9a4595bc7e67 ("[NETLINK]: Add set/getsockopt options to support more than 32 groups")
Fixes: be0c22a46cfb ("netlink: add NETLINK_BROADCAST_ERROR socket option")
Fixes: 38938bfe3489 ("netlink: add NETLINK_NO_ENOBUFS socket flag")
Fixes: 0a6a3a23ea6e ("netlink: add NETLINK_CAP_ACK socket option")
Fixes: 2d4bc93368f5 ("netlink: extended ACK reporting")
Fixes: 89d35528d17d ("netlink: Add new socket option to enable strict checking on dumps")
Reported-by: Brad Spencer &lt;bspencer@blackberry.com&gt;
Link: https://lore.kernel.org/netdev/ZD7VkNWFfp22kTDt@datsun.rim.net/
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Reviewed-by: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Link: https://lore.kernel.org/r/20230421185255.94606-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Brad Spencer provided a detailed report [0] that when calling getsockopt()
for AF_NETLINK, some SOL_NETLINK options set only 1 byte even though such
options require at least sizeof(int) as length.

The options return a flag value that fits into 1 byte, but such behaviour
confuses users who do not initialise the variable before calling
getsockopt() and do not strictly check the returned value as char.

Currently, netlink_getsockopt() uses put_user() to copy data to optlen and
optval, but put_user() casts the data based on the pointer, char *optval.
As a result, only 1 byte is set to optval.

To avoid this behaviour, we need to use copy_to_user() or cast optval for
put_user().

Note that this changes the behaviour on big-endian systems, but we document
that the size of optval is int in the man page.

  $ man 7 netlink
  ...
  Socket options
       To set or get a netlink socket option, call getsockopt(2) to read
       or setsockopt(2) to write the option with the option level argument
       set to SOL_NETLINK.  Unless otherwise noted, optval is a pointer to
       an int.

Fixes: 9a4595bc7e67 ("[NETLINK]: Add set/getsockopt options to support more than 32 groups")
Fixes: be0c22a46cfb ("netlink: add NETLINK_BROADCAST_ERROR socket option")
Fixes: 38938bfe3489 ("netlink: add NETLINK_NO_ENOBUFS socket flag")
Fixes: 0a6a3a23ea6e ("netlink: add NETLINK_CAP_ACK socket option")
Fixes: 2d4bc93368f5 ("netlink: extended ACK reporting")
Fixes: 89d35528d17d ("netlink: Add new socket option to enable strict checking on dumps")
Reported-by: Brad Spencer &lt;bspencer@blackberry.com&gt;
Link: https://lore.kernel.org/netdev/ZD7VkNWFfp22kTDt@datsun.rim.net/
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Reviewed-by: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Link: https://lore.kernel.org/r/20230421185255.94606-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2023-04-06T19:01:20+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-04-06T18:58:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d9c960675adcc6e26bb6464b6b500fd75fd55dcf'/>
<id>d9c960675adcc6e26bb6464b6b500fd75fd55dcf</id>
<content type='text'>
Conflicts:

drivers/net/ethernet/google/gve/gve.h
  3ce934558097 ("gve: Secure enough bytes in the first TX desc for all TCP pkts")
  75eaae158b1b ("gve: Add XDP DROP and TX support for GQI-QPL format")
https://lore.kernel.org/all/20230406104927.45d176f5@canb.auug.org.au/
https://lore.kernel.org/all/c5872985-1a95-0bc8-9dcc-b6f23b439e9d@tessares.net/

Adjacent changes:

net/can/isotp.c
  051737439eae ("can: isotp: fix race between isotp_sendsmg() and isotp_release()")
  96d1c81e6a04 ("can: isotp: add module parameter for maximum pdu size")

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:

drivers/net/ethernet/google/gve/gve.h
  3ce934558097 ("gve: Secure enough bytes in the first TX desc for all TCP pkts")
  75eaae158b1b ("gve: Add XDP DROP and TX support for GQI-QPL format")
https://lore.kernel.org/all/20230406104927.45d176f5@canb.auug.org.au/
https://lore.kernel.org/all/c5872985-1a95-0bc8-9dcc-b6f23b439e9d@tessares.net/

Adjacent changes:

net/can/isotp.c
  051737439eae ("can: isotp: fix race between isotp_sendsmg() and isotp_release()")
  96d1c81e6a04 ("can: isotp: add module parameter for maximum pdu size")

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
