| Message ID | 20230905074638.3304732-1-william.xuanziyang@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v2] team: fix null-ptr-deref when team device type is changed | expand |
On Tue, Sep 05, 2023 at 03:46:38PM +0800, Ziyang Xuan wrote: > diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c > index d3dc22509ea5..12fb5f4cff06 100644 > --- a/drivers/net/team/team.c > +++ b/drivers/net/team/team.c > @@ -2127,7 +2127,10 @@ static const struct ethtool_ops team_ethtool_ops = { > static void team_setup_by_port(struct net_device *dev, > struct net_device *port_dev) > { > - dev->header_ops = port_dev->header_ops; > + if (port_dev->type == ARPHRD_ETHER) > + dev->header_ops = ð_header_ops; > + else > + dev->header_ops = port_dev->header_ops; > dev->type = port_dev->type; > dev->hard_header_len = port_dev->hard_header_len; > dev->needed_headroom = port_dev->needed_headroom; Hmm.. Do we need to export eth_header_ops? I got error like ERROR: modpost: "eth_header_ops" [drivers/net/team/team.ko] undefined! But I saw function loopback_setup() could reference this. Not sure what I missed here. Thanks Hangbin
> On Tue, Sep 05, 2023 at 03:46:38PM +0800, Ziyang Xuan wrote: >> diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c >> index d3dc22509ea5..12fb5f4cff06 100644 >> --- a/drivers/net/team/team.c >> +++ b/drivers/net/team/team.c >> @@ -2127,7 +2127,10 @@ static const struct ethtool_ops team_ethtool_ops = { >> static void team_setup_by_port(struct net_device *dev, >> struct net_device *port_dev) >> { >> - dev->header_ops = port_dev->header_ops; >> + if (port_dev->type == ARPHRD_ETHER) >> + dev->header_ops = ð_header_ops; >> + else >> + dev->header_ops = port_dev->header_ops; >> dev->type = port_dev->type; >> dev->hard_header_len = port_dev->hard_header_len; >> dev->needed_headroom = port_dev->needed_headroom; > > Hmm.. Do we need to export eth_header_ops? I got error like > ERROR: modpost: "eth_header_ops" [drivers/net/team/team.ko] undefined! > > But I saw function loopback_setup() could reference this. Not sure what > I missed here. Yes, I also got the same error, and gave v3 patch with exporting eth_header_ops. drivers/net/loopback.o controlled by CONFIG_NET, CONFIG_NET is bool type and usually Y. So drivers/net/loopback.o does not need to export eth_header_ops. > > Thanks > Hangbin > > . >
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c index d3dc22509ea5..12fb5f4cff06 100644 --- a/drivers/net/team/team.c +++ b/drivers/net/team/team.c @@ -2127,7 +2127,10 @@ static const struct ethtool_ops team_ethtool_ops = { static void team_setup_by_port(struct net_device *dev, struct net_device *port_dev) { - dev->header_ops = port_dev->header_ops; + if (port_dev->type == ARPHRD_ETHER) + dev->header_ops = ð_header_ops; + else + dev->header_ops = port_dev->header_ops; dev->type = port_dev->type; dev->hard_header_len = port_dev->hard_header_len; dev->needed_headroom = port_dev->needed_headroom;
Get a null-ptr-deref bug as follows with reproducer [1]. BUG: kernel NULL pointer dereference, address: 0000000000000228 ... RIP: 0010:vlan_dev_hard_header+0x35/0x140 [8021q] ... Call Trace: <TASK> ? __die+0x24/0x70 ? page_fault_oops+0x82/0x150 ? exc_page_fault+0x69/0x150 ? asm_exc_page_fault+0x26/0x30 ? vlan_dev_hard_header+0x35/0x140 [8021q] ? vlan_dev_hard_header+0x8e/0x140 [8021q] neigh_connected_output+0xb2/0x100 ip6_finish_output2+0x1cb/0x520 ? nf_hook_slow+0x43/0xc0 ? ip6_mtu+0x46/0x80 ip6_finish_output+0x2a/0xb0 mld_sendpack+0x18f/0x250 mld_ifc_work+0x39/0x160 process_one_work+0x1e6/0x3f0 worker_thread+0x4d/0x2f0 ? __pfx_worker_thread+0x10/0x10 kthread+0xe5/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 [1] $ teamd -t team0 -d -c '{"runner": {"name": "loadbalance"}}' $ ip link add name t-dummy type dummy $ ip link add link t-dummy name t-dummy.100 type vlan id 100 $ ip link add name t-nlmon type nlmon $ ip link set t-nlmon master team0 $ ip link set t-nlmon nomaster $ ip link set t-dummy up $ ip link set team0 up $ ip link set t-dummy.100 down $ ip link set t-dummy.100 master team0 When enslave a vlan device to team device and team device type is changed from non-ether to ether, header_ops of team device is changed to vlan_header_ops. That is incorrect and will trigger null-ptr-deref for vlan->real_dev in vlan_dev_hard_header() because team device is not a vlan device. Assign eth_header_ops to header_ops of team device when its type is changed from non-ether to ether to fix the bug. Fixes: 1d76efe1577b ("team: add support for non-ethernet devices") Suggested-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com> --- v2: - Just modify header_ops to eth_header_ops not use ether_setup(). --- drivers/net/team/team.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)