From: Taehee Yoo ap420073@gmail.com
[ Upstream commit 544f287b84959203367cd29e16e772717612fab4 ]
If register_netdevice() is failed, net_device should not be used because variables are uninitialized or freed. So, the routine should be stopped immediately. But, bond_create() doesn't check return value of register_netdevice() immediately. That will result in a panic because of using uninitialized or freed memory.
Test commands: modprobe netdev-notifier-error-inject echo -22 > /sys/kernel/debug/notifier-error-inject/netdev/\ actions/NETDEV_REGISTER/error modprobe bonding max_bonds=3
Splat looks like: [ 375.028492][ T193] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] SMP DEBUG_PAGEALLOC PTI [ 375.033207][ T193] CPU: 2 PID: 193 Comm: kworker/2:2 Not tainted 5.8.0-rc4+ #645 [ 375.036068][ T193] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 375.039673][ T193] Workqueue: events linkwatch_event [ 375.041557][ T193] RIP: 0010:dev_activate+0x4a/0x340 [ 375.043381][ T193] Code: 40 a8 04 0f 85 db 00 00 00 8b 83 08 04 00 00 85 c0 0f 84 0d 01 00 00 31 d2 89 d0 48 8d 04 40 48 c1 e0 07 48 03 83 00 04 00 00 <48> 8b 48 10 f6 41 10 01 75 08 f0 80 a1 a0 01 00 00 fd 48 89 48 08 [ 375.050267][ T193] RSP: 0018:ffff9f8facfcfdd8 EFLAGS: 00010202 [ 375.052410][ T193] RAX: 6b6b6b6b6b6b6b6b RBX: ffff9f8fae6ea000 RCX: 0000000000000006 [ 375.055178][ T193] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9f8fae6ea000 [ 375.057762][ T193] RBP: ffff9f8fae6ea000 R08: 0000000000000000 R09: 0000000000000000 [ 375.059810][ T193] R10: 0000000000000001 R11: 0000000000000000 R12: ffff9f8facfcfe08 [ 375.061892][ T193] R13: ffffffff883587e0 R14: 0000000000000000 R15: ffff9f8fae6ea580 [ 375.063931][ T193] FS: 0000000000000000(0000) GS:ffff9f8fbae00000(0000) knlGS:0000000000000000 [ 375.066239][ T193] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 375.067841][ T193] CR2: 00007f2f542167a0 CR3: 000000012cee6002 CR4: 00000000003606e0 [ 375.069657][ T193] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 375.071471][ T193] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 375.073269][ T193] Call Trace: [ 375.074005][ T193] linkwatch_do_dev+0x4d/0x50 [ 375.075052][ T193] __linkwatch_run_queue+0x10b/0x200 [ 375.076244][ T193] linkwatch_event+0x21/0x30 [ 375.077274][ T193] process_one_work+0x252/0x600 [ 375.078379][ T193] ? process_one_work+0x600/0x600 [ 375.079518][ T193] worker_thread+0x3c/0x380 [ 375.080534][ T193] ? process_one_work+0x600/0x600 [ 375.081668][ T193] kthread+0x139/0x150 [ 375.082567][ T193] ? kthread_park+0x90/0x90 [ 375.083567][ T193] ret_from_fork+0x22/0x30
Fixes: e826eafa65c6 ("bonding: Call netif_carrier_off after register_netdevice") Signed-off-by: Taehee Yoo ap420073@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/bonding/bond_main.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 703c5c2c80e51..499845c32b1bc 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -4864,15 +4864,19 @@ int bond_create(struct net *net, const char *name) bond_dev->rtnl_link_ops = &bond_link_ops;
res = register_netdevice(bond_dev); + if (res < 0) { + free_netdev(bond_dev); + rtnl_unlock(); + + return res; + }
netif_carrier_off(bond_dev);
bond_work_init_all(bond);
rtnl_unlock(); - if (res < 0) - free_netdev(bond_dev); - return res; + return 0; }
static int __net_init bond_net_init(struct net *net)