netdev - [PATCH net v5 03/10] bonding: fix unexpected IFF

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20191021184759.13125-3-ap420073@gmail.com>
Date:   Mon, 21 Oct 2019 18:47:52 +0000
From:   Taehee Yoo <ap420073@...il.com>
To:     davem@...emloft.net, netdev@...r.kernel.org,
        linux-wireless@...r.kernel.org, jakub.kicinski@...ronome.com,
        johannes@...solutions.net, j.vosburgh@...il.com, vfalico@...il.com,
        andy@...yhouse.net, jiri@...nulli.us, sd@...asysnail.net,
        roopa@...ulusnetworks.com, saeedm@...lanox.com,
        manishc@...vell.com, rahulv@...vell.com, kys@...rosoft.com,
        haiyangz@...rosoft.com, stephen@...workplumber.org,
        sashal@...nel.org, hare@...e.de, varun@...lsio.com,
        ubraun@...ux.ibm.com, kgraul@...ux.ibm.com,
        jay.vosburgh@...onical.com, schuffelen@...gle.com, bjorn@...k.no
Cc:     ap420073@...il.com
Subject: [PATCH net v5 03/10] bonding: fix unexpected IFF_BONDING bit unset

The IFF_BONDING means bonding master or bonding slave device.
->ndo_add_slave() sets IFF_BONDING flag and ->ndo_del_slave() unsets
IFF_BONDING flag.

bond0<--bond1

Both bond0 and bond1 are bonding device and these should keep having
IFF_BONDING flag until they are removed.
But bond1 would lose IFF_BONDING at ->ndo_del_slave() because that routine
do not check whether the slave device is the bonding type or not.
This patch adds the interface type check routine before removing
IFF_BONDING flag.

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

Splat looks like:
[  226.665555] proc_dir_entry 'bonding/bond1' already registered
[  226.666440] WARNING: CPU: 0 PID: 737 at fs/proc/generic.c:361 proc_register+0x2a9/0x3e0
[  226.667571] Modules linked in: bonding af_packet sch_fq_codel ip_tables x_tables unix
[  226.668662] CPU: 0 PID: 737 Comm: ip Not tainted 5.4.0-rc3+ #96
[  226.669508] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  226.670652] RIP: 0010:proc_register+0x2a9/0x3e0
[  226.671612] Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 39 01 00 00 48 8b 04 24 48 89 ea 48 c7 c7 a0 0b 14 9f 48 8b b0 e
0 00 00 00 e8 07 e7 88 ff <0f> 0b 48 c7 c7 40 2d a5 9f e8 59 d6 23 01 48 8b 4c 24 10 48 b8 00
[  226.675007] RSP: 0018:ffff888050e17078 EFLAGS: 00010282
[  226.675761] RAX: dffffc0000000008 RBX: ffff88805fdd0f10 RCX: ffffffff9dd344e2
[  226.676757] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88806c9f6b8c
[  226.677751] RBP: ffff8880507160f3 R08: ffffed100d940019 R09: ffffed100d940019
[  226.678761] R10: 0000000000000001 R11: ffffed100d940018 R12: ffff888050716008
[  226.679757] R13: ffff8880507160f2 R14: dffffc0000000000 R15: ffffed100a0e2c1e
[  226.680758] FS:  00007fdc217cc0c0(0000) GS:ffff88806c800000(0000) knlGS:0000000000000000
[  226.681886] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  226.682719] CR2: 00007f49313424d0 CR3: 0000000050e46001 CR4: 00000000000606f0
[  226.683727] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  226.684725] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  226.685681] Call Trace:
[  226.687089]  proc_create_seq_private+0xb3/0xf0
[  226.687778]  bond_create_proc_entry+0x1b3/0x3f0 [bonding]
[  226.691458]  bond_netdev_event+0x433/0x970 [bonding]
[  226.692139]  ? __module_text_address+0x13/0x140
[  226.692779]  notifier_call_chain+0x90/0x160
[  226.693401]  register_netdevice+0x9b3/0xd80
[  226.694010]  ? alloc_netdev_mqs+0x854/0xc10
[  226.694629]  ? netdev_change_features+0xa0/0xa0
[  226.695278]  ? rtnl_create_link+0x2ed/0xad0
[  226.695849]  bond_newlink+0x2a/0x60 [bonding]
[  226.696422]  __rtnl_newlink+0xb9f/0x11b0
[  226.696968]  ? rtnl_link_unregister+0x220/0x220
[ ... ]

Fixes: 0b680e753724 ("[PATCH] bonding: Add priv_flag to avoid event mishandling")
Signed-off-by: Taehee Yoo <ap420073@...il.com>
---

v2 -> v5 :
 - This patch is not changed
v1 -> v2 :
 - Do not add a new priv_flag.

 drivers/net/bonding/bond_main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index ac1b09b56c77..92713b93f66f 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1816,7 +1816,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 	slave_disable_netpoll(new_slave);
 
 err_close:
-	slave_dev->priv_flags &= ~IFF_BONDING;
+	if (!netif_is_bond_master(slave_dev))
+		slave_dev->priv_flags &= ~IFF_BONDING;
 	dev_close(slave_dev);
 
 err_restore_mac:
@@ -2017,7 +2018,8 @@ static int __bond_release_one(struct net_device *bond_dev,
 	else
 		dev_set_mtu(slave_dev, slave->original_mtu);
 
-	slave_dev->priv_flags &= ~IFF_BONDING;
+	if (!netif_is_bond_master(slave_dev))
+		slave_dev->priv_flags &= ~IFF_BONDING;
 
 	bond_free_slave(slave);
 
-- 
2.17.1