<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/net/bonding, branch linux-5.6.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>bonding: Fix reference count leak in bond_sysfs_slave_add.</title>
<updated>2020-06-03T06:23:37+00:00</updated>
<author>
<name>Qiushi Wu</name>
<email>wu000273@umn.edu</email>
</author>
<published>2020-05-28T03:10:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f939d23ce8d78760f7b952a80e4dc56735096ee0'/>
<id>f939d23ce8d78760f7b952a80e4dc56735096ee0</id>
<content type='text'>
commit a068aab42258e25094bc2c159948d263ed7d7a77 upstream.

kobject_init_and_add() takes reference even when it fails.
If this function returns an error, kobject_put() must be called to
properly clean up the memory associated with the object. Previous
commit "b8eb718348b8" fixed a similar problem.

Fixes: 07699f9a7c8d ("bonding: add sysfs /slave dir for bond slave devices.")
Signed-off-by: Qiushi Wu &lt;wu000273@umn.edu&gt;
Acked-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a068aab42258e25094bc2c159948d263ed7d7a77 upstream.

kobject_init_and_add() takes reference even when it fails.
If this function returns an error, kobject_put() must be called to
properly clean up the memory associated with the object. Previous
commit "b8eb718348b8" fixed a similar problem.

Fixes: 07699f9a7c8d ("bonding: add sysfs /slave dir for bond slave devices.")
Signed-off-by: Qiushi Wu &lt;wu000273@umn.edu&gt;
Acked-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>bonding/alb: make sure arp header is pulled before accessing it</title>
<updated>2020-03-07T06:00:10+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2020-03-04T17:32:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b7469e83d2add567e4e0b063963db185f3167cea'/>
<id>b7469e83d2add567e4e0b063963db185f3167cea</id>
<content type='text'>
Similar to commit 38f88c454042 ("bonding/alb: properly access headers
in bond_alb_xmit()"), we need to make sure arp header was pulled
in skb-&gt;head before blindly accessing it in rlb_arp_xmit().

Remove arp_pkt() private helper, since it is more readable/obvious
to have the following construct back to back :

	if (!pskb_network_may_pull(skb, sizeof(*arp)))
		return NULL;
	arp = (struct arp_pkt *)skb_network_header(skb);

syzbot reported :

BUG: KMSAN: uninit-value in bond_slave_has_mac_rx include/net/bonding.h:704 [inline]
BUG: KMSAN: uninit-value in rlb_arp_xmit drivers/net/bonding/bond_alb.c:662 [inline]
BUG: KMSAN: uninit-value in bond_alb_xmit+0x575/0x25e0 drivers/net/bonding/bond_alb.c:1477
CPU: 0 PID: 12743 Comm: syz-executor.4 Not tainted 5.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 bond_slave_has_mac_rx include/net/bonding.h:704 [inline]
 rlb_arp_xmit drivers/net/bonding/bond_alb.c:662 [inline]
 bond_alb_xmit+0x575/0x25e0 drivers/net/bonding/bond_alb.c:1477
 __bond_start_xmit drivers/net/bonding/bond_main.c:4257 [inline]
 bond_start_xmit+0x85d/0x2f70 drivers/net/bonding/bond_main.c:4282
 __netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 netdev_start_xmit include/linux/netdevice.h:4538 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0x531/0xab0 net/core/dev.c:3486
 __dev_queue_xmit+0x37de/0x4220 net/core/dev.c:4063
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4096
 packet_snd net/packet/af_packet.c:2967 [inline]
 packet_sendmsg+0x8347/0x93b0 net/packet/af_packet.c:2992
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0xc1b/0xc50 net/socket.c:1998
 __do_sys_sendto net/socket.c:2010 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:2006
 __x64_sys_sendto+0x6e/0x90 net/socket.c:2006
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c479
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc77ffbbc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fc77ffbc6d4 RCX: 000000000045c479
RDX: 000000000000000e RSI: 00000000200004c0 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a04 R14: 00000000004cc7b0 R15: 000000000076bf2c

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82
 slab_alloc_node mm/slub.c:2793 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4401
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1051 [inline]
 alloc_skb_with_frags+0x18c/0xa70 net/core/skbuff.c:5766
 sock_alloc_send_pskb+0xada/0xc60 net/core/sock.c:2242
 packet_alloc_skb net/packet/af_packet.c:2815 [inline]
 packet_snd net/packet/af_packet.c:2910 [inline]
 packet_sendmsg+0x66a0/0x93b0 net/packet/af_packet.c:2992
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0xc1b/0xc50 net/socket.c:1998
 __do_sys_sendto net/socket.c:2010 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:2006
 __x64_sys_sendto+0x6e/0x90 net/socket.c:2006
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
Cc: Veaceslav Falico &lt;vfalico@gmail.com&gt;
Cc: Andy Gospodarek &lt;andy@greyhouse.net&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>
Similar to commit 38f88c454042 ("bonding/alb: properly access headers
in bond_alb_xmit()"), we need to make sure arp header was pulled
in skb-&gt;head before blindly accessing it in rlb_arp_xmit().

Remove arp_pkt() private helper, since it is more readable/obvious
to have the following construct back to back :

	if (!pskb_network_may_pull(skb, sizeof(*arp)))
		return NULL;
	arp = (struct arp_pkt *)skb_network_header(skb);

syzbot reported :

BUG: KMSAN: uninit-value in bond_slave_has_mac_rx include/net/bonding.h:704 [inline]
BUG: KMSAN: uninit-value in rlb_arp_xmit drivers/net/bonding/bond_alb.c:662 [inline]
BUG: KMSAN: uninit-value in bond_alb_xmit+0x575/0x25e0 drivers/net/bonding/bond_alb.c:1477
CPU: 0 PID: 12743 Comm: syz-executor.4 Not tainted 5.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 bond_slave_has_mac_rx include/net/bonding.h:704 [inline]
 rlb_arp_xmit drivers/net/bonding/bond_alb.c:662 [inline]
 bond_alb_xmit+0x575/0x25e0 drivers/net/bonding/bond_alb.c:1477
 __bond_start_xmit drivers/net/bonding/bond_main.c:4257 [inline]
 bond_start_xmit+0x85d/0x2f70 drivers/net/bonding/bond_main.c:4282
 __netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 netdev_start_xmit include/linux/netdevice.h:4538 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0x531/0xab0 net/core/dev.c:3486
 __dev_queue_xmit+0x37de/0x4220 net/core/dev.c:4063
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4096
 packet_snd net/packet/af_packet.c:2967 [inline]
 packet_sendmsg+0x8347/0x93b0 net/packet/af_packet.c:2992
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0xc1b/0xc50 net/socket.c:1998
 __do_sys_sendto net/socket.c:2010 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:2006
 __x64_sys_sendto+0x6e/0x90 net/socket.c:2006
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c479
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc77ffbbc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fc77ffbc6d4 RCX: 000000000045c479
RDX: 000000000000000e RSI: 00000000200004c0 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a04 R14: 00000000004cc7b0 R15: 000000000076bf2c

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82
 slab_alloc_node mm/slub.c:2793 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4401
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1051 [inline]
 alloc_skb_with_frags+0x18c/0xa70 net/core/skbuff.c:5766
 sock_alloc_send_pskb+0xada/0xc60 net/core/sock.c:2242
 packet_alloc_skb net/packet/af_packet.c:2815 [inline]
 packet_snd net/packet/af_packet.c:2910 [inline]
 packet_sendmsg+0x66a0/0x93b0 net/packet/af_packet.c:2992
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0xc1b/0xc50 net/socket.c:1998
 __do_sys_sendto net/socket.c:2010 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:2006
 __x64_sys_sendto+0x6e/0x90 net/socket.c:2006
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
Cc: Veaceslav Falico &lt;vfalico@gmail.com&gt;
Cc: Andy Gospodarek &lt;andy@greyhouse.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: fix lockdep warning in bond_get_stats()</title>
<updated>2020-02-17T03:32:11+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2020-02-15T10:50:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b3e80d44f5b1b470dd9e2dbc6816e63a5c519709'/>
<id>b3e80d44f5b1b470dd9e2dbc6816e63a5c519709</id>
<content type='text'>
In the "struct bonding", there is stats_lock.
This lock protects "bond_stats" in the "struct bonding".
bond_stats is updated in the bond_get_stats() and this function would be
executed concurrently. So, the lock is needed.

Bonding interfaces would be nested.
So, either stats_lock should use dynamic lockdep class key or stats_lock
should be used by spin_lock_nested(). In the current code, stats_lock is
using a dynamic lockdep class key.
But there is no updating stats_lock_key routine So, lockdep warning
will occur.

Test commands:
    ip link add bond0 type bond
    ip link add bond1 type bond
    ip link set bond0 master bond1
    ip link set bond0 nomaster
    ip link set bond1 master bond0

Splat looks like:
[   38.420603][  T957] 5.5.0+ #394 Not tainted
[   38.421074][  T957] ------------------------------------------------------
[   38.421837][  T957] ip/957 is trying to acquire lock:
[   38.422399][  T957] ffff888063262cd8 (&amp;bond-&gt;stats_lock_key#2){+.+.}, at: bond_get_stats+0x90/0x4d0 [bonding]
[   38.423528][  T957]
[   38.423528][  T957] but task is already holding lock:
[   38.424526][  T957] ffff888065fd2cd8 (&amp;bond-&gt;stats_lock_key){+.+.}, at: bond_get_stats+0x90/0x4d0 [bonding]
[   38.426075][  T957]
[   38.426075][  T957] which lock already depends on the new lock.
[   38.426075][  T957]
[   38.428536][  T957]
[   38.428536][  T957] the existing dependency chain (in reverse order) is:
[   38.429475][  T957]
[   38.429475][  T957] -&gt; #1 (&amp;bond-&gt;stats_lock_key){+.+.}:
[   38.430273][  T957]        _raw_spin_lock+0x30/0x70
[   38.430812][  T957]        bond_get_stats+0x90/0x4d0 [bonding]
[   38.431451][  T957]        dev_get_stats+0x1ec/0x270
[   38.432088][  T957]        bond_get_stats+0x1a5/0x4d0 [bonding]
[   38.432767][  T957]        dev_get_stats+0x1ec/0x270
[   38.433322][  T957]        rtnl_fill_stats+0x44/0xbe0
[   38.433866][  T957]        rtnl_fill_ifinfo+0xeb2/0x3720
[   38.434474][  T957]        rtmsg_ifinfo_build_skb+0xca/0x170
[   38.435081][  T957]        rtmsg_ifinfo_event.part.33+0x1b/0xb0
[   38.436848][  T957]        rtnetlink_event+0xcd/0x120
[   38.437455][  T957]        notifier_call_chain+0x90/0x160
[   38.438067][  T957]        netdev_change_features+0x74/0xa0
[   38.438708][  T957]        bond_compute_features.isra.45+0x4e6/0x6f0 [bonding]
[   38.439522][  T957]        bond_enslave+0x3639/0x47b0 [bonding]
[   38.440225][  T957]        do_setlink+0xaab/0x2ef0
[   38.440786][  T957]        __rtnl_newlink+0x9c5/0x1270
[   38.441463][  T957]        rtnl_newlink+0x65/0x90
[   38.442075][  T957]        rtnetlink_rcv_msg+0x4a8/0x890
[   38.442774][  T957]        netlink_rcv_skb+0x121/0x350
[   38.443451][  T957]        netlink_unicast+0x42e/0x610
[   38.444282][  T957]        netlink_sendmsg+0x65a/0xb90
[   38.444992][  T957]        ____sys_sendmsg+0x5ce/0x7a0
[   38.445679][  T957]        ___sys_sendmsg+0x10f/0x1b0
[   38.446365][  T957]        __sys_sendmsg+0xc6/0x150
[   38.447007][  T957]        do_syscall_64+0x99/0x4f0
[   38.447668][  T957]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   38.448538][  T957]
[   38.448538][  T957] -&gt; #0 (&amp;bond-&gt;stats_lock_key#2){+.+.}:
[   38.449554][  T957]        __lock_acquire+0x2d8d/0x3de0
[   38.450148][  T957]        lock_acquire+0x164/0x3b0
[   38.450711][  T957]        _raw_spin_lock+0x30/0x70
[   38.451292][  T957]        bond_get_stats+0x90/0x4d0 [bonding]
[   38.451950][  T957]        dev_get_stats+0x1ec/0x270
[   38.452425][  T957]        bond_get_stats+0x1a5/0x4d0 [bonding]
[   38.453362][  T957]        dev_get_stats+0x1ec/0x270
[   38.453825][  T957]        rtnl_fill_stats+0x44/0xbe0
[   38.454390][  T957]        rtnl_fill_ifinfo+0xeb2/0x3720
[   38.456257][  T957]        rtmsg_ifinfo_build_skb+0xca/0x170
[   38.456998][  T957]        rtmsg_ifinfo_event.part.33+0x1b/0xb0
[   38.459351][  T957]        rtnetlink_event+0xcd/0x120
[   38.460086][  T957]        notifier_call_chain+0x90/0x160
[   38.460829][  T957]        netdev_change_features+0x74/0xa0
[   38.461752][  T957]        bond_compute_features.isra.45+0x4e6/0x6f0 [bonding]
[   38.462705][  T957]        bond_enslave+0x3639/0x47b0 [bonding]
[   38.463476][  T957]        do_setlink+0xaab/0x2ef0
[   38.464141][  T957]        __rtnl_newlink+0x9c5/0x1270
[   38.464897][  T957]        rtnl_newlink+0x65/0x90
[   38.465522][  T957]        rtnetlink_rcv_msg+0x4a8/0x890
[   38.466215][  T957]        netlink_rcv_skb+0x121/0x350
[   38.466895][  T957]        netlink_unicast+0x42e/0x610
[   38.467583][  T957]        netlink_sendmsg+0x65a/0xb90
[   38.468285][  T957]        ____sys_sendmsg+0x5ce/0x7a0
[   38.469202][  T957]        ___sys_sendmsg+0x10f/0x1b0
[   38.469884][  T957]        __sys_sendmsg+0xc6/0x150
[   38.470587][  T957]        do_syscall_64+0x99/0x4f0
[   38.471245][  T957]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   38.472093][  T957]
[   38.472093][  T957] other info that might help us debug this:
[   38.472093][  T957]
[   38.473438][  T957]  Possible unsafe locking scenario:
[   38.473438][  T957]
[   38.474898][  T957]        CPU0                    CPU1
[   38.476234][  T957]        ----                    ----
[   38.480171][  T957]   lock(&amp;bond-&gt;stats_lock_key);
[   38.480808][  T957]                                lock(&amp;bond-&gt;stats_lock_key#2);
[   38.481791][  T957]                                lock(&amp;bond-&gt;stats_lock_key);
[   38.482754][  T957]   lock(&amp;bond-&gt;stats_lock_key#2);
[   38.483416][  T957]
[   38.483416][  T957]  *** DEADLOCK ***
[   38.483416][  T957]
[   38.484505][  T957] 3 locks held by ip/957:
[   38.485048][  T957]  #0: ffffffffbccf6230 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x457/0x890
[   38.486198][  T957]  #1: ffff888065fd2cd8 (&amp;bond-&gt;stats_lock_key){+.+.}, at: bond_get_stats+0x90/0x4d0 [bonding]
[   38.487625][  T957]  #2: ffffffffbc9254c0 (rcu_read_lock){....}, at: bond_get_stats+0x5/0x4d0 [bonding]
[   38.488897][  T957]
[   38.488897][  T957] stack backtrace:
[   38.489646][  T957] CPU: 1 PID: 957 Comm: ip Not tainted 5.5.0+ #394
[   38.490497][  T957] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   38.492810][  T957] Call Trace:
[   38.493219][  T957]  dump_stack+0x96/0xdb
[   38.493709][  T957]  check_noncircular+0x371/0x450
[   38.494344][  T957]  ? lookup_address+0x60/0x60
[   38.494923][  T957]  ? print_circular_bug.isra.35+0x310/0x310
[   38.495699][  T957]  ? hlock_class+0x130/0x130
[   38.496334][  T957]  ? __lock_acquire+0x2d8d/0x3de0
[   38.496979][  T957]  __lock_acquire+0x2d8d/0x3de0
[   38.497607][  T957]  ? register_lock_class+0x14d0/0x14d0
[   38.498333][  T957]  ? check_chain_key+0x236/0x5d0
[   38.499003][  T957]  lock_acquire+0x164/0x3b0
[   38.499800][  T957]  ? bond_get_stats+0x90/0x4d0 [bonding]
[   38.500706][  T957]  _raw_spin_lock+0x30/0x70
[   38.501435][  T957]  ? bond_get_stats+0x90/0x4d0 [bonding]
[   38.502311][  T957]  bond_get_stats+0x90/0x4d0 [bonding]
[ ... ]

But, there is another problem.
The dynamic lockdep class key is protected by RTNL, but bond_get_stats()
would be called outside of RTNL.
So, it would use an invalid dynamic lockdep class key.

In order to fix this issue, stats_lock uses spin_lock_nested() instead of
a dynamic lockdep key.
The bond_get_stats() calls bond_get_lowest_level_rcu() to get the correct
nest level value, which will be used by spin_lock_nested().
The "dev-&gt;lower_level" indicates lower nest level value, but this value
is invalid outside of RTNL.
So, bond_get_lowest_level_rcu() returns valid lower nest level value in
the RCU critical section.
bond_get_lowest_level_rcu() will be work only when LOCKDEP is enabled.

Fixes: 089bca2caed0 ("bonding: use dynamic lockdep key instead of subclass")
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.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>
In the "struct bonding", there is stats_lock.
This lock protects "bond_stats" in the "struct bonding".
bond_stats is updated in the bond_get_stats() and this function would be
executed concurrently. So, the lock is needed.

Bonding interfaces would be nested.
So, either stats_lock should use dynamic lockdep class key or stats_lock
should be used by spin_lock_nested(). In the current code, stats_lock is
using a dynamic lockdep class key.
But there is no updating stats_lock_key routine So, lockdep warning
will occur.

Test commands:
    ip link add bond0 type bond
    ip link add bond1 type bond
    ip link set bond0 master bond1
    ip link set bond0 nomaster
    ip link set bond1 master bond0

Splat looks like:
[   38.420603][  T957] 5.5.0+ #394 Not tainted
[   38.421074][  T957] ------------------------------------------------------
[   38.421837][  T957] ip/957 is trying to acquire lock:
[   38.422399][  T957] ffff888063262cd8 (&amp;bond-&gt;stats_lock_key#2){+.+.}, at: bond_get_stats+0x90/0x4d0 [bonding]
[   38.423528][  T957]
[   38.423528][  T957] but task is already holding lock:
[   38.424526][  T957] ffff888065fd2cd8 (&amp;bond-&gt;stats_lock_key){+.+.}, at: bond_get_stats+0x90/0x4d0 [bonding]
[   38.426075][  T957]
[   38.426075][  T957] which lock already depends on the new lock.
[   38.426075][  T957]
[   38.428536][  T957]
[   38.428536][  T957] the existing dependency chain (in reverse order) is:
[   38.429475][  T957]
[   38.429475][  T957] -&gt; #1 (&amp;bond-&gt;stats_lock_key){+.+.}:
[   38.430273][  T957]        _raw_spin_lock+0x30/0x70
[   38.430812][  T957]        bond_get_stats+0x90/0x4d0 [bonding]
[   38.431451][  T957]        dev_get_stats+0x1ec/0x270
[   38.432088][  T957]        bond_get_stats+0x1a5/0x4d0 [bonding]
[   38.432767][  T957]        dev_get_stats+0x1ec/0x270
[   38.433322][  T957]        rtnl_fill_stats+0x44/0xbe0
[   38.433866][  T957]        rtnl_fill_ifinfo+0xeb2/0x3720
[   38.434474][  T957]        rtmsg_ifinfo_build_skb+0xca/0x170
[   38.435081][  T957]        rtmsg_ifinfo_event.part.33+0x1b/0xb0
[   38.436848][  T957]        rtnetlink_event+0xcd/0x120
[   38.437455][  T957]        notifier_call_chain+0x90/0x160
[   38.438067][  T957]        netdev_change_features+0x74/0xa0
[   38.438708][  T957]        bond_compute_features.isra.45+0x4e6/0x6f0 [bonding]
[   38.439522][  T957]        bond_enslave+0x3639/0x47b0 [bonding]
[   38.440225][  T957]        do_setlink+0xaab/0x2ef0
[   38.440786][  T957]        __rtnl_newlink+0x9c5/0x1270
[   38.441463][  T957]        rtnl_newlink+0x65/0x90
[   38.442075][  T957]        rtnetlink_rcv_msg+0x4a8/0x890
[   38.442774][  T957]        netlink_rcv_skb+0x121/0x350
[   38.443451][  T957]        netlink_unicast+0x42e/0x610
[   38.444282][  T957]        netlink_sendmsg+0x65a/0xb90
[   38.444992][  T957]        ____sys_sendmsg+0x5ce/0x7a0
[   38.445679][  T957]        ___sys_sendmsg+0x10f/0x1b0
[   38.446365][  T957]        __sys_sendmsg+0xc6/0x150
[   38.447007][  T957]        do_syscall_64+0x99/0x4f0
[   38.447668][  T957]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   38.448538][  T957]
[   38.448538][  T957] -&gt; #0 (&amp;bond-&gt;stats_lock_key#2){+.+.}:
[   38.449554][  T957]        __lock_acquire+0x2d8d/0x3de0
[   38.450148][  T957]        lock_acquire+0x164/0x3b0
[   38.450711][  T957]        _raw_spin_lock+0x30/0x70
[   38.451292][  T957]        bond_get_stats+0x90/0x4d0 [bonding]
[   38.451950][  T957]        dev_get_stats+0x1ec/0x270
[   38.452425][  T957]        bond_get_stats+0x1a5/0x4d0 [bonding]
[   38.453362][  T957]        dev_get_stats+0x1ec/0x270
[   38.453825][  T957]        rtnl_fill_stats+0x44/0xbe0
[   38.454390][  T957]        rtnl_fill_ifinfo+0xeb2/0x3720
[   38.456257][  T957]        rtmsg_ifinfo_build_skb+0xca/0x170
[   38.456998][  T957]        rtmsg_ifinfo_event.part.33+0x1b/0xb0
[   38.459351][  T957]        rtnetlink_event+0xcd/0x120
[   38.460086][  T957]        notifier_call_chain+0x90/0x160
[   38.460829][  T957]        netdev_change_features+0x74/0xa0
[   38.461752][  T957]        bond_compute_features.isra.45+0x4e6/0x6f0 [bonding]
[   38.462705][  T957]        bond_enslave+0x3639/0x47b0 [bonding]
[   38.463476][  T957]        do_setlink+0xaab/0x2ef0
[   38.464141][  T957]        __rtnl_newlink+0x9c5/0x1270
[   38.464897][  T957]        rtnl_newlink+0x65/0x90
[   38.465522][  T957]        rtnetlink_rcv_msg+0x4a8/0x890
[   38.466215][  T957]        netlink_rcv_skb+0x121/0x350
[   38.466895][  T957]        netlink_unicast+0x42e/0x610
[   38.467583][  T957]        netlink_sendmsg+0x65a/0xb90
[   38.468285][  T957]        ____sys_sendmsg+0x5ce/0x7a0
[   38.469202][  T957]        ___sys_sendmsg+0x10f/0x1b0
[   38.469884][  T957]        __sys_sendmsg+0xc6/0x150
[   38.470587][  T957]        do_syscall_64+0x99/0x4f0
[   38.471245][  T957]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   38.472093][  T957]
[   38.472093][  T957] other info that might help us debug this:
[   38.472093][  T957]
[   38.473438][  T957]  Possible unsafe locking scenario:
[   38.473438][  T957]
[   38.474898][  T957]        CPU0                    CPU1
[   38.476234][  T957]        ----                    ----
[   38.480171][  T957]   lock(&amp;bond-&gt;stats_lock_key);
[   38.480808][  T957]                                lock(&amp;bond-&gt;stats_lock_key#2);
[   38.481791][  T957]                                lock(&amp;bond-&gt;stats_lock_key);
[   38.482754][  T957]   lock(&amp;bond-&gt;stats_lock_key#2);
[   38.483416][  T957]
[   38.483416][  T957]  *** DEADLOCK ***
[   38.483416][  T957]
[   38.484505][  T957] 3 locks held by ip/957:
[   38.485048][  T957]  #0: ffffffffbccf6230 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x457/0x890
[   38.486198][  T957]  #1: ffff888065fd2cd8 (&amp;bond-&gt;stats_lock_key){+.+.}, at: bond_get_stats+0x90/0x4d0 [bonding]
[   38.487625][  T957]  #2: ffffffffbc9254c0 (rcu_read_lock){....}, at: bond_get_stats+0x5/0x4d0 [bonding]
[   38.488897][  T957]
[   38.488897][  T957] stack backtrace:
[   38.489646][  T957] CPU: 1 PID: 957 Comm: ip Not tainted 5.5.0+ #394
[   38.490497][  T957] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   38.492810][  T957] Call Trace:
[   38.493219][  T957]  dump_stack+0x96/0xdb
[   38.493709][  T957]  check_noncircular+0x371/0x450
[   38.494344][  T957]  ? lookup_address+0x60/0x60
[   38.494923][  T957]  ? print_circular_bug.isra.35+0x310/0x310
[   38.495699][  T957]  ? hlock_class+0x130/0x130
[   38.496334][  T957]  ? __lock_acquire+0x2d8d/0x3de0
[   38.496979][  T957]  __lock_acquire+0x2d8d/0x3de0
[   38.497607][  T957]  ? register_lock_class+0x14d0/0x14d0
[   38.498333][  T957]  ? check_chain_key+0x236/0x5d0
[   38.499003][  T957]  lock_acquire+0x164/0x3b0
[   38.499800][  T957]  ? bond_get_stats+0x90/0x4d0 [bonding]
[   38.500706][  T957]  _raw_spin_lock+0x30/0x70
[   38.501435][  T957]  ? bond_get_stats+0x90/0x4d0 [bonding]
[   38.502311][  T957]  bond_get_stats+0x90/0x4d0 [bonding]
[ ... ]

But, there is another problem.
The dynamic lockdep class key is protected by RTNL, but bond_get_stats()
would be called outside of RTNL.
So, it would use an invalid dynamic lockdep class key.

In order to fix this issue, stats_lock uses spin_lock_nested() instead of
a dynamic lockdep key.
The bond_get_stats() calls bond_get_lowest_level_rcu() to get the correct
nest level value, which will be used by spin_lock_nested().
The "dev-&gt;lower_level" indicates lower nest level value, but this value
is invalid outside of RTNL.
So, bond_get_lowest_level_rcu() returns valid lower nest level value in
the RCU critical section.
bond_get_lowest_level_rcu() will be work only when LOCKDEP is enabled.

Fixes: 089bca2caed0 ("bonding: use dynamic lockdep key instead of subclass")
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: add missing netdev_update_lockdep_key()</title>
<updated>2020-02-17T03:32:11+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2020-02-15T10:50:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=064ff66e2bef84f1153087612032b5b9eab005bd'/>
<id>064ff66e2bef84f1153087612032b5b9eab005bd</id>
<content type='text'>
After bond_release(), netdev_update_lockdep_key() should be called.
But both ioctl path and attribute path don't call
netdev_update_lockdep_key().
This patch adds missing netdev_update_lockdep_key().

Test commands:
    ip link add bond0 type bond
    ip link add bond1 type bond
    ifenslave bond0 bond1
    ifenslave -d bond0 bond1
    ifenslave bond1 bond0

Splat looks like:
[   29.501182][ T1046] WARNING: possible circular locking dependency detected
[   29.501945][ T1039] hardirqs last disabled at (1962): [&lt;ffffffffac6c807f&gt;] handle_mm_fault+0x13f/0x700
[   29.503442][ T1046] 5.5.0+ #322 Not tainted
[   29.503447][ T1046] ------------------------------------------------------
[   29.504277][ T1039] softirqs last  enabled at (1180): [&lt;ffffffffade00678&gt;] __do_softirq+0x678/0x981
[   29.505443][ T1046] ifenslave/1046 is trying to acquire lock:
[   29.505886][ T1039] softirqs last disabled at (1169): [&lt;ffffffffac19c18a&gt;] irq_exit+0x17a/0x1a0
[   29.509997][ T1046] ffff88805d5da280 (&amp;dev-&gt;addr_list_lock_key#3){+...}, at: dev_mc_sync_multiple+0x95/0x120
[   29.511243][ T1046]
[   29.511243][ T1046] but task is already holding lock:
[   29.512192][ T1046] ffff8880460f2280 (&amp;dev-&gt;addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding]
[   29.514124][ T1046]
[   29.514124][ T1046] which lock already depends on the new lock.
[   29.514124][ T1046]
[   29.517297][ T1046]
[   29.517297][ T1046] the existing dependency chain (in reverse order) is:
[   29.518231][ T1046]
[   29.518231][ T1046] -&gt; #1 (&amp;dev-&gt;addr_list_lock_key#4){+...}:
[   29.519076][ T1046]        _raw_spin_lock+0x30/0x70
[   29.519588][ T1046]        dev_mc_sync_multiple+0x95/0x120
[   29.520208][ T1046]        bond_enslave+0x448d/0x47b0 [bonding]
[   29.520862][ T1046]        bond_option_slaves_set+0x1a3/0x370 [bonding]
[   29.521640][ T1046]        __bond_opt_set+0x1ff/0xbb0 [bonding]
[   29.522438][ T1046]        __bond_opt_set_notify+0x2b/0xf0 [bonding]
[   29.523251][ T1046]        bond_opt_tryset_rtnl+0x92/0xf0 [bonding]
[   29.524082][ T1046]        bonding_sysfs_store_option+0x8a/0xf0 [bonding]
[   29.524959][ T1046]        kernfs_fop_write+0x276/0x410
[   29.525620][ T1046]        vfs_write+0x197/0x4a0
[   29.526218][ T1046]        ksys_write+0x141/0x1d0
[   29.526818][ T1046]        do_syscall_64+0x99/0x4f0
[   29.527430][ T1046]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.528265][ T1046]
[   29.528265][ T1046] -&gt; #0 (&amp;dev-&gt;addr_list_lock_key#3){+...}:
[   29.529272][ T1046]        __lock_acquire+0x2d8d/0x3de0
[   29.529935][ T1046]        lock_acquire+0x164/0x3b0
[   29.530638][ T1046]        _raw_spin_lock+0x30/0x70
[   29.531187][ T1046]        dev_mc_sync_multiple+0x95/0x120
[   29.531790][ T1046]        bond_enslave+0x448d/0x47b0 [bonding]
[   29.532451][ T1046]        bond_option_slaves_set+0x1a3/0x370 [bonding]
[   29.533163][ T1046]        __bond_opt_set+0x1ff/0xbb0 [bonding]
[   29.533789][ T1046]        __bond_opt_set_notify+0x2b/0xf0 [bonding]
[   29.534595][ T1046]        bond_opt_tryset_rtnl+0x92/0xf0 [bonding]
[   29.535500][ T1046]        bonding_sysfs_store_option+0x8a/0xf0 [bonding]
[   29.536379][ T1046]        kernfs_fop_write+0x276/0x410
[   29.537057][ T1046]        vfs_write+0x197/0x4a0
[   29.537640][ T1046]        ksys_write+0x141/0x1d0
[   29.538251][ T1046]        do_syscall_64+0x99/0x4f0
[   29.538870][ T1046]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.539659][ T1046]
[   29.539659][ T1046] other info that might help us debug this:
[   29.539659][ T1046]
[   29.540953][ T1046]  Possible unsafe locking scenario:
[   29.540953][ T1046]
[   29.541883][ T1046]        CPU0                    CPU1
[   29.542540][ T1046]        ----                    ----
[   29.543209][ T1046]   lock(&amp;dev-&gt;addr_list_lock_key#4);
[   29.543880][ T1046]                                lock(&amp;dev-&gt;addr_list_lock_key#3);
[   29.544873][ T1046]                                lock(&amp;dev-&gt;addr_list_lock_key#4);
[   29.545863][ T1046]   lock(&amp;dev-&gt;addr_list_lock_key#3);
[   29.546525][ T1046]
[   29.546525][ T1046]  *** DEADLOCK ***
[   29.546525][ T1046]
[   29.547542][ T1046] 5 locks held by ifenslave/1046:
[   29.548196][ T1046]  #0: ffff88806044c478 (sb_writers#5){.+.+}, at: vfs_write+0x3bb/0x4a0
[   29.549248][ T1046]  #1: ffff88805af00890 (&amp;of-&gt;mutex){+.+.}, at: kernfs_fop_write+0x1cf/0x410
[   29.550343][ T1046]  #2: ffff88805b8b54b0 (kn-&gt;count#157){.+.+}, at: kernfs_fop_write+0x1f2/0x410
[   29.551575][ T1046]  #3: ffffffffaecf4cf0 (rtnl_mutex){+.+.}, at: bond_opt_tryset_rtnl+0x5f/0xf0 [bonding]
[   29.552819][ T1046]  #4: ffff8880460f2280 (&amp;dev-&gt;addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding]
[   29.554175][ T1046]
[   29.554175][ T1046] stack backtrace:
[   29.554907][ T1046] CPU: 0 PID: 1046 Comm: ifenslave Not tainted 5.5.0+ #322
[   29.555854][ T1046] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   29.557064][ T1046] Call Trace:
[   29.557504][ T1046]  dump_stack+0x96/0xdb
[   29.558054][ T1046]  check_noncircular+0x371/0x450
[   29.558723][ T1046]  ? print_circular_bug.isra.35+0x310/0x310
[   29.559486][ T1046]  ? hlock_class+0x130/0x130
[   29.560100][ T1046]  ? __lock_acquire+0x2d8d/0x3de0
[   29.560761][ T1046]  __lock_acquire+0x2d8d/0x3de0
[   29.561366][ T1046]  ? register_lock_class+0x14d0/0x14d0
[   29.562045][ T1046]  ? find_held_lock+0x39/0x1d0
[   29.562641][ T1046]  lock_acquire+0x164/0x3b0
[   29.563199][ T1046]  ? dev_mc_sync_multiple+0x95/0x120
[   29.563872][ T1046]  _raw_spin_lock+0x30/0x70
[   29.564464][ T1046]  ? dev_mc_sync_multiple+0x95/0x120
[   29.565146][ T1046]  dev_mc_sync_multiple+0x95/0x120
[   29.565793][ T1046]  bond_enslave+0x448d/0x47b0 [bonding]
[   29.566487][ T1046]  ? bond_update_slave_arr+0x940/0x940 [bonding]
[   29.567279][ T1046]  ? bstr_printf+0xc20/0xc20
[   29.567857][ T1046]  ? stack_trace_consume_entry+0x160/0x160
[   29.568614][ T1046]  ? deactivate_slab.isra.77+0x2c5/0x800
[   29.569320][ T1046]  ? check_chain_key+0x236/0x5d0
[   29.569939][ T1046]  ? sscanf+0x93/0xc0
[   29.570442][ T1046]  ? vsscanf+0x1e20/0x1e20
[   29.571003][ T1046]  bond_option_slaves_set+0x1a3/0x370 [bonding]
[ ... ]

Fixes: ab92d68fc22f ("net: core: add generic lockdep keys")
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.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>
After bond_release(), netdev_update_lockdep_key() should be called.
But both ioctl path and attribute path don't call
netdev_update_lockdep_key().
This patch adds missing netdev_update_lockdep_key().

Test commands:
    ip link add bond0 type bond
    ip link add bond1 type bond
    ifenslave bond0 bond1
    ifenslave -d bond0 bond1
    ifenslave bond1 bond0

Splat looks like:
[   29.501182][ T1046] WARNING: possible circular locking dependency detected
[   29.501945][ T1039] hardirqs last disabled at (1962): [&lt;ffffffffac6c807f&gt;] handle_mm_fault+0x13f/0x700
[   29.503442][ T1046] 5.5.0+ #322 Not tainted
[   29.503447][ T1046] ------------------------------------------------------
[   29.504277][ T1039] softirqs last  enabled at (1180): [&lt;ffffffffade00678&gt;] __do_softirq+0x678/0x981
[   29.505443][ T1046] ifenslave/1046 is trying to acquire lock:
[   29.505886][ T1039] softirqs last disabled at (1169): [&lt;ffffffffac19c18a&gt;] irq_exit+0x17a/0x1a0
[   29.509997][ T1046] ffff88805d5da280 (&amp;dev-&gt;addr_list_lock_key#3){+...}, at: dev_mc_sync_multiple+0x95/0x120
[   29.511243][ T1046]
[   29.511243][ T1046] but task is already holding lock:
[   29.512192][ T1046] ffff8880460f2280 (&amp;dev-&gt;addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding]
[   29.514124][ T1046]
[   29.514124][ T1046] which lock already depends on the new lock.
[   29.514124][ T1046]
[   29.517297][ T1046]
[   29.517297][ T1046] the existing dependency chain (in reverse order) is:
[   29.518231][ T1046]
[   29.518231][ T1046] -&gt; #1 (&amp;dev-&gt;addr_list_lock_key#4){+...}:
[   29.519076][ T1046]        _raw_spin_lock+0x30/0x70
[   29.519588][ T1046]        dev_mc_sync_multiple+0x95/0x120
[   29.520208][ T1046]        bond_enslave+0x448d/0x47b0 [bonding]
[   29.520862][ T1046]        bond_option_slaves_set+0x1a3/0x370 [bonding]
[   29.521640][ T1046]        __bond_opt_set+0x1ff/0xbb0 [bonding]
[   29.522438][ T1046]        __bond_opt_set_notify+0x2b/0xf0 [bonding]
[   29.523251][ T1046]        bond_opt_tryset_rtnl+0x92/0xf0 [bonding]
[   29.524082][ T1046]        bonding_sysfs_store_option+0x8a/0xf0 [bonding]
[   29.524959][ T1046]        kernfs_fop_write+0x276/0x410
[   29.525620][ T1046]        vfs_write+0x197/0x4a0
[   29.526218][ T1046]        ksys_write+0x141/0x1d0
[   29.526818][ T1046]        do_syscall_64+0x99/0x4f0
[   29.527430][ T1046]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.528265][ T1046]
[   29.528265][ T1046] -&gt; #0 (&amp;dev-&gt;addr_list_lock_key#3){+...}:
[   29.529272][ T1046]        __lock_acquire+0x2d8d/0x3de0
[   29.529935][ T1046]        lock_acquire+0x164/0x3b0
[   29.530638][ T1046]        _raw_spin_lock+0x30/0x70
[   29.531187][ T1046]        dev_mc_sync_multiple+0x95/0x120
[   29.531790][ T1046]        bond_enslave+0x448d/0x47b0 [bonding]
[   29.532451][ T1046]        bond_option_slaves_set+0x1a3/0x370 [bonding]
[   29.533163][ T1046]        __bond_opt_set+0x1ff/0xbb0 [bonding]
[   29.533789][ T1046]        __bond_opt_set_notify+0x2b/0xf0 [bonding]
[   29.534595][ T1046]        bond_opt_tryset_rtnl+0x92/0xf0 [bonding]
[   29.535500][ T1046]        bonding_sysfs_store_option+0x8a/0xf0 [bonding]
[   29.536379][ T1046]        kernfs_fop_write+0x276/0x410
[   29.537057][ T1046]        vfs_write+0x197/0x4a0
[   29.537640][ T1046]        ksys_write+0x141/0x1d0
[   29.538251][ T1046]        do_syscall_64+0x99/0x4f0
[   29.538870][ T1046]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.539659][ T1046]
[   29.539659][ T1046] other info that might help us debug this:
[   29.539659][ T1046]
[   29.540953][ T1046]  Possible unsafe locking scenario:
[   29.540953][ T1046]
[   29.541883][ T1046]        CPU0                    CPU1
[   29.542540][ T1046]        ----                    ----
[   29.543209][ T1046]   lock(&amp;dev-&gt;addr_list_lock_key#4);
[   29.543880][ T1046]                                lock(&amp;dev-&gt;addr_list_lock_key#3);
[   29.544873][ T1046]                                lock(&amp;dev-&gt;addr_list_lock_key#4);
[   29.545863][ T1046]   lock(&amp;dev-&gt;addr_list_lock_key#3);
[   29.546525][ T1046]
[   29.546525][ T1046]  *** DEADLOCK ***
[   29.546525][ T1046]
[   29.547542][ T1046] 5 locks held by ifenslave/1046:
[   29.548196][ T1046]  #0: ffff88806044c478 (sb_writers#5){.+.+}, at: vfs_write+0x3bb/0x4a0
[   29.549248][ T1046]  #1: ffff88805af00890 (&amp;of-&gt;mutex){+.+.}, at: kernfs_fop_write+0x1cf/0x410
[   29.550343][ T1046]  #2: ffff88805b8b54b0 (kn-&gt;count#157){.+.+}, at: kernfs_fop_write+0x1f2/0x410
[   29.551575][ T1046]  #3: ffffffffaecf4cf0 (rtnl_mutex){+.+.}, at: bond_opt_tryset_rtnl+0x5f/0xf0 [bonding]
[   29.552819][ T1046]  #4: ffff8880460f2280 (&amp;dev-&gt;addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding]
[   29.554175][ T1046]
[   29.554175][ T1046] stack backtrace:
[   29.554907][ T1046] CPU: 0 PID: 1046 Comm: ifenslave Not tainted 5.5.0+ #322
[   29.555854][ T1046] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   29.557064][ T1046] Call Trace:
[   29.557504][ T1046]  dump_stack+0x96/0xdb
[   29.558054][ T1046]  check_noncircular+0x371/0x450
[   29.558723][ T1046]  ? print_circular_bug.isra.35+0x310/0x310
[   29.559486][ T1046]  ? hlock_class+0x130/0x130
[   29.560100][ T1046]  ? __lock_acquire+0x2d8d/0x3de0
[   29.560761][ T1046]  __lock_acquire+0x2d8d/0x3de0
[   29.561366][ T1046]  ? register_lock_class+0x14d0/0x14d0
[   29.562045][ T1046]  ? find_held_lock+0x39/0x1d0
[   29.562641][ T1046]  lock_acquire+0x164/0x3b0
[   29.563199][ T1046]  ? dev_mc_sync_multiple+0x95/0x120
[   29.563872][ T1046]  _raw_spin_lock+0x30/0x70
[   29.564464][ T1046]  ? dev_mc_sync_multiple+0x95/0x120
[   29.565146][ T1046]  dev_mc_sync_multiple+0x95/0x120
[   29.565793][ T1046]  bond_enslave+0x448d/0x47b0 [bonding]
[   29.566487][ T1046]  ? bond_update_slave_arr+0x940/0x940 [bonding]
[   29.567279][ T1046]  ? bstr_printf+0xc20/0xc20
[   29.567857][ T1046]  ? stack_trace_consume_entry+0x160/0x160
[   29.568614][ T1046]  ? deactivate_slab.isra.77+0x2c5/0x800
[   29.569320][ T1046]  ? check_chain_key+0x236/0x5d0
[   29.569939][ T1046]  ? sscanf+0x93/0xc0
[   29.570442][ T1046]  ? vsscanf+0x1e20/0x1e20
[   29.571003][ T1046]  bond_option_slaves_set+0x1a3/0x370 [bonding]
[ ... ]

Fixes: ab92d68fc22f ("net: core: add generic lockdep keys")
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding/alb: properly access headers in bond_alb_xmit()</title>
<updated>2020-02-05T13:28:09+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2020-02-05T03:26:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=38f88c45404293bbc027b956def6c10cbd45c616'/>
<id>38f88c45404293bbc027b956def6c10cbd45c616</id>
<content type='text'>
syzbot managed to send an IPX packet through bond_alb_xmit()
and af_packet and triggered a use-after-free.

First, bond_alb_xmit() was using ipx_hdr() helper to reach
the IPX header, but ipx_hdr() was using the transport offset
instead of the network offset. In the particular syzbot
report transport offset was 0xFFFF

This patch removes ipx_hdr() since it was only (mis)used from bonding.

Then we need to make sure IPv4/IPv6/IPX headers are pulled
in skb-&gt;head before dereferencing anything.

BUG: KASAN: use-after-free in bond_alb_xmit+0x153a/0x1590 drivers/net/bonding/bond_alb.c:1452
Read of size 2 at addr ffff8801ce56dfff by task syz-executor.2/18108
 (if (ipx_hdr(skb)-&gt;ipx_checksum != IPX_NO_CHECKSUM) ...)

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 [&lt;ffffffff8441fc42&gt;] __dump_stack lib/dump_stack.c:17 [inline]
 [&lt;ffffffff8441fc42&gt;] dump_stack+0x14d/0x20b lib/dump_stack.c:53
 [&lt;ffffffff81a7dec4&gt;] print_address_description+0x6f/0x20b mm/kasan/report.c:282
 [&lt;ffffffff81a7e0ec&gt;] kasan_report_error mm/kasan/report.c:380 [inline]
 [&lt;ffffffff81a7e0ec&gt;] kasan_report mm/kasan/report.c:438 [inline]
 [&lt;ffffffff81a7e0ec&gt;] kasan_report.cold+0x8c/0x2a0 mm/kasan/report.c:422
 [&lt;ffffffff81a7dc4f&gt;] __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:469
 [&lt;ffffffff82c8c00a&gt;] bond_alb_xmit+0x153a/0x1590 drivers/net/bonding/bond_alb.c:1452
 [&lt;ffffffff82c60c74&gt;] __bond_start_xmit drivers/net/bonding/bond_main.c:4199 [inline]
 [&lt;ffffffff82c60c74&gt;] bond_start_xmit+0x4f4/0x1570 drivers/net/bonding/bond_main.c:4224
 [&lt;ffffffff83baa558&gt;] __netdev_start_xmit include/linux/netdevice.h:4525 [inline]
 [&lt;ffffffff83baa558&gt;] netdev_start_xmit include/linux/netdevice.h:4539 [inline]
 [&lt;ffffffff83baa558&gt;] xmit_one net/core/dev.c:3611 [inline]
 [&lt;ffffffff83baa558&gt;] dev_hard_start_xmit+0x168/0x910 net/core/dev.c:3627
 [&lt;ffffffff83bacf35&gt;] __dev_queue_xmit+0x1f55/0x33b0 net/core/dev.c:4238
 [&lt;ffffffff83bae3a8&gt;] dev_queue_xmit+0x18/0x20 net/core/dev.c:4278
 [&lt;ffffffff84339189&gt;] packet_snd net/packet/af_packet.c:3226 [inline]
 [&lt;ffffffff84339189&gt;] packet_sendmsg+0x4919/0x70b0 net/packet/af_packet.c:3252
 [&lt;ffffffff83b1ac0c&gt;] sock_sendmsg_nosec net/socket.c:673 [inline]
 [&lt;ffffffff83b1ac0c&gt;] sock_sendmsg+0x12c/0x160 net/socket.c:684
 [&lt;ffffffff83b1f5a2&gt;] __sys_sendto+0x262/0x380 net/socket.c:1996
 [&lt;ffffffff83b1f700&gt;] SYSC_sendto net/socket.c:2008 [inline]
 [&lt;ffffffff83b1f700&gt;] SyS_sendto+0x40/0x60 net/socket.c:2004

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
Cc: Veaceslav Falico &lt;vfalico@gmail.com&gt;
Cc: Andy Gospodarek &lt;andy@greyhouse.net&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>
syzbot managed to send an IPX packet through bond_alb_xmit()
and af_packet and triggered a use-after-free.

First, bond_alb_xmit() was using ipx_hdr() helper to reach
the IPX header, but ipx_hdr() was using the transport offset
instead of the network offset. In the particular syzbot
report transport offset was 0xFFFF

This patch removes ipx_hdr() since it was only (mis)used from bonding.

Then we need to make sure IPv4/IPv6/IPX headers are pulled
in skb-&gt;head before dereferencing anything.

BUG: KASAN: use-after-free in bond_alb_xmit+0x153a/0x1590 drivers/net/bonding/bond_alb.c:1452
Read of size 2 at addr ffff8801ce56dfff by task syz-executor.2/18108
 (if (ipx_hdr(skb)-&gt;ipx_checksum != IPX_NO_CHECKSUM) ...)

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 [&lt;ffffffff8441fc42&gt;] __dump_stack lib/dump_stack.c:17 [inline]
 [&lt;ffffffff8441fc42&gt;] dump_stack+0x14d/0x20b lib/dump_stack.c:53
 [&lt;ffffffff81a7dec4&gt;] print_address_description+0x6f/0x20b mm/kasan/report.c:282
 [&lt;ffffffff81a7e0ec&gt;] kasan_report_error mm/kasan/report.c:380 [inline]
 [&lt;ffffffff81a7e0ec&gt;] kasan_report mm/kasan/report.c:438 [inline]
 [&lt;ffffffff81a7e0ec&gt;] kasan_report.cold+0x8c/0x2a0 mm/kasan/report.c:422
 [&lt;ffffffff81a7dc4f&gt;] __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:469
 [&lt;ffffffff82c8c00a&gt;] bond_alb_xmit+0x153a/0x1590 drivers/net/bonding/bond_alb.c:1452
 [&lt;ffffffff82c60c74&gt;] __bond_start_xmit drivers/net/bonding/bond_main.c:4199 [inline]
 [&lt;ffffffff82c60c74&gt;] bond_start_xmit+0x4f4/0x1570 drivers/net/bonding/bond_main.c:4224
 [&lt;ffffffff83baa558&gt;] __netdev_start_xmit include/linux/netdevice.h:4525 [inline]
 [&lt;ffffffff83baa558&gt;] netdev_start_xmit include/linux/netdevice.h:4539 [inline]
 [&lt;ffffffff83baa558&gt;] xmit_one net/core/dev.c:3611 [inline]
 [&lt;ffffffff83baa558&gt;] dev_hard_start_xmit+0x168/0x910 net/core/dev.c:3627
 [&lt;ffffffff83bacf35&gt;] __dev_queue_xmit+0x1f55/0x33b0 net/core/dev.c:4238
 [&lt;ffffffff83bae3a8&gt;] dev_queue_xmit+0x18/0x20 net/core/dev.c:4278
 [&lt;ffffffff84339189&gt;] packet_snd net/packet/af_packet.c:3226 [inline]
 [&lt;ffffffff84339189&gt;] packet_sendmsg+0x4919/0x70b0 net/packet/af_packet.c:3252
 [&lt;ffffffff83b1ac0c&gt;] sock_sendmsg_nosec net/socket.c:673 [inline]
 [&lt;ffffffff83b1ac0c&gt;] sock_sendmsg+0x12c/0x160 net/socket.c:684
 [&lt;ffffffff83b1f5a2&gt;] __sys_sendto+0x262/0x380 net/socket.c:1996
 [&lt;ffffffff83b1f700&gt;] SYSC_sendto net/socket.c:2008 [inline]
 [&lt;ffffffff83b1f700&gt;] SyS_sendto+0x40/0x60 net/socket.c:2004

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
Cc: Veaceslav Falico &lt;vfalico@gmail.com&gt;
Cc: Andy Gospodarek &lt;andy@greyhouse.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: rename AD_STATE_* to LACP_STATE_*</title>
<updated>2019-12-26T21:09:37+00:00</updated>
<author>
<name>Andy Roulin</name>
<email>aroulin@cumulusnetworks.com</email>
</author>
<published>2019-12-26T13:41:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c1e469902640ed0a82d0b8df5951199c17a49e3c'/>
<id>c1e469902640ed0a82d0b8df5951199c17a49e3c</id>
<content type='text'>
As the LACP actor/partner state is now part of the uapi, rename the
3ad state defines with LACP prefix. The LACP prefix is preferred over
BOND_3AD as the LACP standard moved to 802.1AX.

Fixes: 826f66b30c2e3 ("bonding: move 802.3ad port state flags to uapi")
Signed-off-by: Andy Roulin &lt;aroulin@cumulusnetworks.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>
As the LACP actor/partner state is now part of the uapi, rename the
3ad state defines with LACP prefix. The LACP prefix is preferred over
BOND_3AD as the LACP standard moved to 802.1AX.

Fixes: 826f66b30c2e3 ("bonding: move 802.3ad port state flags to uapi")
Signed-off-by: Andy Roulin &lt;aroulin@cumulusnetworks.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>2019-12-22T23:15:05+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2019-12-22T23:15:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ac80010fc94eb0680d9a432b639583bd7ac29066'/>
<id>ac80010fc94eb0680d9a432b639583bd7ac29066</id>
<content type='text'>
Mere overlapping changes in the conflicts here.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Mere overlapping changes in the conflicts here.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: fix active-backup transition after link failure</title>
<updated>2019-12-15T00:22:34+00:00</updated>
<author>
<name>Mahesh Bandewar</name>
<email>maheshb@google.com</email>
</author>
<published>2019-12-06T23:44:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5d485ed88d48f8101a2067348e267c0aaf4ed486'/>
<id>5d485ed88d48f8101a2067348e267c0aaf4ed486</id>
<content type='text'>
After the recent fix in commit 1899bb325149 ("bonding: fix state
transition issue in link monitoring"), the active-backup mode with
miimon initially come-up fine but after a link-failure, both members
transition into backup state.

Following steps to reproduce the scenario (eth1 and eth2 are the
slaves of the bond):

    ip link set eth1 up
    ip link set eth2 down
    sleep 1
    ip link set eth2 up
    ip link set eth1 down
    cat /sys/class/net/eth1/bonding_slave/state
    cat /sys/class/net/eth2/bonding_slave/state

Fixes: 1899bb325149 ("bonding: fix state transition issue in link monitoring")
CC: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: Mahesh Bandewar &lt;maheshb@google.com&gt;
Acked-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: Jakub Kicinski &lt;jakub.kicinski@netronome.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
After the recent fix in commit 1899bb325149 ("bonding: fix state
transition issue in link monitoring"), the active-backup mode with
miimon initially come-up fine but after a link-failure, both members
transition into backup state.

Following steps to reproduce the scenario (eth1 and eth2 are the
slaves of the bond):

    ip link set eth1 up
    ip link set eth2 down
    sleep 1
    ip link set eth2 up
    ip link set eth1 down
    cat /sys/class/net/eth1/bonding_slave/state
    cat /sys/class/net/eth2/bonding_slave/state

Fixes: 1899bb325149 ("bonding: fix state transition issue in link monitoring")
CC: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: Mahesh Bandewar &lt;maheshb@google.com&gt;
Acked-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: Jakub Kicinski &lt;jakub.kicinski@netronome.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: move 802.3ad port state flags to uapi</title>
<updated>2019-12-14T21:07:44+00:00</updated>
<author>
<name>Andy Roulin</name>
<email>aroulin@cumulusnetworks.com</email>
</author>
<published>2019-12-11T22:30:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=826f66b30c2e3d4df533e4224cb8c734afa0a17c'/>
<id>826f66b30c2e3d4df533e4224cb8c734afa0a17c</id>
<content type='text'>
The bond slave actor/partner operating state is exported as
bitfield to userspace, which lacks a way to interpret it, e.g.,
iproute2 only prints the state as a number:

ad_actor_oper_port_state 15

For userspace to interpret the bitfield, the bitfield definitions
should be part of the uapi. The bitfield itself is defined in the
802.3ad standard.

This commit moves the 802.3ad bitfield definitions to uapi.

Related iproute2 patches, soon to be posted upstream, use the new uapi
headers to pretty-print bond slave state, e.g., with ip -d link show

ad_actor_oper_port_state_str &lt;active,short_timeout,aggregating,in_sync&gt;

Signed-off-by: Andy Roulin &lt;aroulin@cumulusnetworks.com&gt;
Acked-by: Roopa Prabhu &lt;roopa@cumulusnetworks.com&gt;
Acked-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: Jakub Kicinski &lt;jakub.kicinski@netronome.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The bond slave actor/partner operating state is exported as
bitfield to userspace, which lacks a way to interpret it, e.g.,
iproute2 only prints the state as a number:

ad_actor_oper_port_state 15

For userspace to interpret the bitfield, the bitfield definitions
should be part of the uapi. The bitfield itself is defined in the
802.3ad standard.

This commit moves the 802.3ad bitfield definitions to uapi.

Related iproute2 patches, soon to be posted upstream, use the new uapi
headers to pretty-print bond slave state, e.g., with ip -d link show

ad_actor_oper_port_state_str &lt;active,short_timeout,aggregating,in_sync&gt;

Signed-off-by: Andy Roulin &lt;aroulin@cumulusnetworks.com&gt;
Acked-by: Roopa Prabhu &lt;roopa@cumulusnetworks.com&gt;
Acked-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: Jakub Kicinski &lt;jakub.kicinski@netronome.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: fix bond_neigh_init()</title>
<updated>2019-12-09T17:49:07+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-12-07T22:10:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9e99bfefdbce2e23ef37487a3bcb4adf90a791d1'/>
<id>9e99bfefdbce2e23ef37487a3bcb4adf90a791d1</id>
<content type='text'>
1) syzbot reported an uninit-value in bond_neigh_setup() [1]

 bond_neigh_setup() uses a temporary on-stack 'struct neigh_parms parms',
 but only clears parms.neigh_setup field.

 A stacked bonding device would then enter bond_neigh_setup()
 and read garbage from parms-&gt;dev.

 If we get really unlucky and garbage is matching @dev, then we
 could recurse and eventually crash.

 Let's make sure the whole structure is cleared to avoid surprises.

2) bond_neigh_setup() can be called while another cpu manipulates
 the master device, removing or adding a slave.
 We need at least rcu protection to prevent use-after-free.

Note: Prior code does not support a stack of bonding devices,
      this patch does not attempt to fix this, and leave a comment instead.

[1]

BUG: KMSAN: uninit-value in bond_neigh_setup+0xa4/0x110 drivers/net/bonding/bond_main.c:3655
CPU: 0 PID: 11256 Comm: syz-executor.0 Not tainted 5.4.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 &lt;IRQ&gt;
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108
 __msan_warning+0x57/0xa0 mm/kmsan/kmsan_instr.c:245
 bond_neigh_setup+0xa4/0x110 drivers/net/bonding/bond_main.c:3655
 bond_neigh_init+0x216/0x4b0 drivers/net/bonding/bond_main.c:3626
 ___neigh_create+0x169e/0x2c40 net/core/neighbour.c:613
 __neigh_create+0xbd/0xd0 net/core/neighbour.c:674
 ip6_finish_output2+0x149a/0x2670 net/ipv6/ip6_output.c:113
 __ip6_finish_output+0x83d/0x8f0 net/ipv6/ip6_output.c:142
 ip6_finish_output+0x2db/0x420 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 mld_sendpack+0xebd/0x13d0 net/ipv6/mcast.c:1682
 mld_send_cr net/ipv6/mcast.c:1978 [inline]
 mld_ifc_timer_expire+0x116b/0x1680 net/ipv6/mcast.c:2477
 call_timer_fn+0x232/0x530 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers+0xd60/0x1270 kernel/time/timer.c:1773
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786
 __do_softirq+0x4a1/0x83a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:375 [inline]
 irq_exit+0x230/0x280 kernel/softirq.c:416
 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:536
 smp_apic_timer_interrupt+0x48/0x70 arch/x86/kernel/apic/apic.c:1138
 apic_timer_interrupt+0x2e/0x40 arch/x86/entry/entry_64.S:835
 &lt;/IRQ&gt;
RIP: 0010:kmsan_free_page+0x18d/0x1c0 mm/kmsan/kmsan_shadow.c:439
Code: 4c 89 ff 44 89 f6 e8 82 0d ee ff 65 ff 0d 9f 26 3b 60 65 8b 05 98 26 3b 60 85 c0 75 24 e8 5b f6 35 ff 4c 89 6d d0 ff 75 d0 9d &lt;48&gt; 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b 0f 0b 0f 0b 0f
RSP: 0018:ffffb328034af818 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffffe2d7471f8360 RCX: 0000000000000000
RDX: ffffffffadea7000 RSI: 0000000000000004 RDI: ffff93496fcda104
RBP: ffffb328034af850 R08: ffff934a47e86d00 R09: ffff93496fc41900
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000246 R14: 0000000000000000 R15: ffffe2d7472225c0
 free_pages_prepare mm/page_alloc.c:1138 [inline]
 free_pcp_prepare mm/page_alloc.c:1230 [inline]
 free_unref_page_prepare+0x1d9/0x770 mm/page_alloc.c:3025
 free_unref_page mm/page_alloc.c:3074 [inline]
 free_the_page mm/page_alloc.c:4832 [inline]
 __free_pages+0x154/0x230 mm/page_alloc.c:4840
 __vunmap+0xdac/0xf20 mm/vmalloc.c:2277
 __vfree mm/vmalloc.c:2325 [inline]
 vfree+0x7c/0x170 mm/vmalloc.c:2355
 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:883 [inline]
 get_entries net/ipv6/netfilter/ip6_tables.c:1041 [inline]
 do_ip6t_get_ctl+0xfa4/0x1030 net/ipv6/netfilter/ip6_tables.c:1709
 nf_sockopt net/netfilter/nf_sockopt.c:104 [inline]
 nf_getsockopt+0x481/0x4e0 net/netfilter/nf_sockopt.c:122
 ipv6_getsockopt+0x264/0x510 net/ipv6/ipv6_sockglue.c:1400
 tcp_getsockopt+0x1c6/0x1f0 net/ipv4/tcp.c:3688
 sock_common_getsockopt+0x13f/0x180 net/core/sock.c:3110
 __sys_getsockopt+0x533/0x7b0 net/socket.c:2129
 __do_sys_getsockopt net/socket.c:2144 [inline]
 __se_sys_getsockopt+0xe1/0x100 net/socket.c:2141
 __x64_sys_getsockopt+0x62/0x80 net/socket.c:2141
 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d20a
Code: b8 34 01 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 8d 8b fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 37 00 00 00 0f 05 &lt;48&gt; 3d 01 f0 ff ff 0f 83 6a 8b fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:0000000000a6f618 EFLAGS: 00000212 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 0000000000a6f640 RCX: 000000000045d20a
RDX: 0000000000000041 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 0000000000717cc0 R08: 0000000000a6f63c R09: 0000000000004000
R10: 0000000000a6f740 R11: 0000000000000212 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000000029 R15: 0000000000715b00

Local variable description: ----parms@bond_neigh_init
Variable was created at:
 bond_neigh_init+0x8c/0x4b0 drivers/net/bonding/bond_main.c:3617
 bond_neigh_init+0x8c/0x4b0 drivers/net/bonding/bond_main.c:3617

Fixes: 9918d5bf329d ("bonding: modify only neigh_parms owned by us")
Fixes: 234bcf8a499e ("net/bonding: correctly proxy slave neigh param setup ndo function")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
Cc: Veaceslav Falico &lt;vfalico@gmail.com&gt;
Cc: Andy Gospodarek &lt;andy@greyhouse.net&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>
1) syzbot reported an uninit-value in bond_neigh_setup() [1]

 bond_neigh_setup() uses a temporary on-stack 'struct neigh_parms parms',
 but only clears parms.neigh_setup field.

 A stacked bonding device would then enter bond_neigh_setup()
 and read garbage from parms-&gt;dev.

 If we get really unlucky and garbage is matching @dev, then we
 could recurse and eventually crash.

 Let's make sure the whole structure is cleared to avoid surprises.

2) bond_neigh_setup() can be called while another cpu manipulates
 the master device, removing or adding a slave.
 We need at least rcu protection to prevent use-after-free.

Note: Prior code does not support a stack of bonding devices,
      this patch does not attempt to fix this, and leave a comment instead.

[1]

BUG: KMSAN: uninit-value in bond_neigh_setup+0xa4/0x110 drivers/net/bonding/bond_main.c:3655
CPU: 0 PID: 11256 Comm: syz-executor.0 Not tainted 5.4.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 &lt;IRQ&gt;
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108
 __msan_warning+0x57/0xa0 mm/kmsan/kmsan_instr.c:245
 bond_neigh_setup+0xa4/0x110 drivers/net/bonding/bond_main.c:3655
 bond_neigh_init+0x216/0x4b0 drivers/net/bonding/bond_main.c:3626
 ___neigh_create+0x169e/0x2c40 net/core/neighbour.c:613
 __neigh_create+0xbd/0xd0 net/core/neighbour.c:674
 ip6_finish_output2+0x149a/0x2670 net/ipv6/ip6_output.c:113
 __ip6_finish_output+0x83d/0x8f0 net/ipv6/ip6_output.c:142
 ip6_finish_output+0x2db/0x420 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 mld_sendpack+0xebd/0x13d0 net/ipv6/mcast.c:1682
 mld_send_cr net/ipv6/mcast.c:1978 [inline]
 mld_ifc_timer_expire+0x116b/0x1680 net/ipv6/mcast.c:2477
 call_timer_fn+0x232/0x530 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers+0xd60/0x1270 kernel/time/timer.c:1773
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786
 __do_softirq+0x4a1/0x83a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:375 [inline]
 irq_exit+0x230/0x280 kernel/softirq.c:416
 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:536
 smp_apic_timer_interrupt+0x48/0x70 arch/x86/kernel/apic/apic.c:1138
 apic_timer_interrupt+0x2e/0x40 arch/x86/entry/entry_64.S:835
 &lt;/IRQ&gt;
RIP: 0010:kmsan_free_page+0x18d/0x1c0 mm/kmsan/kmsan_shadow.c:439
Code: 4c 89 ff 44 89 f6 e8 82 0d ee ff 65 ff 0d 9f 26 3b 60 65 8b 05 98 26 3b 60 85 c0 75 24 e8 5b f6 35 ff 4c 89 6d d0 ff 75 d0 9d &lt;48&gt; 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b 0f 0b 0f 0b 0f
RSP: 0018:ffffb328034af818 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffffe2d7471f8360 RCX: 0000000000000000
RDX: ffffffffadea7000 RSI: 0000000000000004 RDI: ffff93496fcda104
RBP: ffffb328034af850 R08: ffff934a47e86d00 R09: ffff93496fc41900
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000246 R14: 0000000000000000 R15: ffffe2d7472225c0
 free_pages_prepare mm/page_alloc.c:1138 [inline]
 free_pcp_prepare mm/page_alloc.c:1230 [inline]
 free_unref_page_prepare+0x1d9/0x770 mm/page_alloc.c:3025
 free_unref_page mm/page_alloc.c:3074 [inline]
 free_the_page mm/page_alloc.c:4832 [inline]
 __free_pages+0x154/0x230 mm/page_alloc.c:4840
 __vunmap+0xdac/0xf20 mm/vmalloc.c:2277
 __vfree mm/vmalloc.c:2325 [inline]
 vfree+0x7c/0x170 mm/vmalloc.c:2355
 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:883 [inline]
 get_entries net/ipv6/netfilter/ip6_tables.c:1041 [inline]
 do_ip6t_get_ctl+0xfa4/0x1030 net/ipv6/netfilter/ip6_tables.c:1709
 nf_sockopt net/netfilter/nf_sockopt.c:104 [inline]
 nf_getsockopt+0x481/0x4e0 net/netfilter/nf_sockopt.c:122
 ipv6_getsockopt+0x264/0x510 net/ipv6/ipv6_sockglue.c:1400
 tcp_getsockopt+0x1c6/0x1f0 net/ipv4/tcp.c:3688
 sock_common_getsockopt+0x13f/0x180 net/core/sock.c:3110
 __sys_getsockopt+0x533/0x7b0 net/socket.c:2129
 __do_sys_getsockopt net/socket.c:2144 [inline]
 __se_sys_getsockopt+0xe1/0x100 net/socket.c:2141
 __x64_sys_getsockopt+0x62/0x80 net/socket.c:2141
 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d20a
Code: b8 34 01 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 8d 8b fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 37 00 00 00 0f 05 &lt;48&gt; 3d 01 f0 ff ff 0f 83 6a 8b fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:0000000000a6f618 EFLAGS: 00000212 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 0000000000a6f640 RCX: 000000000045d20a
RDX: 0000000000000041 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 0000000000717cc0 R08: 0000000000a6f63c R09: 0000000000004000
R10: 0000000000a6f740 R11: 0000000000000212 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000000029 R15: 0000000000715b00

Local variable description: ----parms@bond_neigh_init
Variable was created at:
 bond_neigh_init+0x8c/0x4b0 drivers/net/bonding/bond_main.c:3617
 bond_neigh_init+0x8c/0x4b0 drivers/net/bonding/bond_main.c:3617

Fixes: 9918d5bf329d ("bonding: modify only neigh_parms owned by us")
Fixes: 234bcf8a499e ("net/bonding: correctly proxy slave neigh param setup ndo function")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Cc: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
Cc: Veaceslav Falico &lt;vfalico@gmail.com&gt;
Cc: Andy Gospodarek &lt;andy@greyhouse.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
