[PATCH 5.4 11/34] i40e: fix use-after-free in i40e_sync_filters_subtask()

From: Greg Kroah-Hartman
Date: Mon Jan 10 2022 - 02:31:16 EST


From: Di Zhu <zhudi2@xxxxxxxxxx>

commit 3116f59c12bd24c513194cd3acb3ec1f7d468954 upstream.

Using ifconfig command to delete the ipv6 address will cause
the i40e network card driver to delete its internal mac_filter and
i40e_service_task kernel thread will concurrently access the mac_filter.
These two processes are not protected by lock
so causing the following use-after-free problems.

print_address_description+0x70/0x360
? vprintk_func+0x5e/0xf0
kasan_report+0x1b2/0x330
i40e_sync_vsi_filters+0x4f0/0x1850 [i40e]
i40e_sync_filters_subtask+0xe3/0x130 [i40e]
i40e_service_task+0x195/0x24c0 [i40e]
process_one_work+0x3f5/0x7d0
worker_thread+0x61/0x6c0
? process_one_work+0x7d0/0x7d0
kthread+0x1c3/0x1f0
? kthread_park+0xc0/0xc0
ret_from_fork+0x35/0x40

Allocated by task 2279810:
kasan_kmalloc+0xa0/0xd0
kmem_cache_alloc_trace+0xf3/0x1e0
i40e_add_filter+0x127/0x2b0 [i40e]
i40e_add_mac_filter+0x156/0x190 [i40e]
i40e_addr_sync+0x2d/0x40 [i40e]
__hw_addr_sync_dev+0x154/0x210
i40e_set_rx_mode+0x6d/0xf0 [i40e]
__dev_set_rx_mode+0xfb/0x1f0
__dev_mc_add+0x6c/0x90
igmp6_group_added+0x214/0x230
__ipv6_dev_mc_inc+0x338/0x4f0
addrconf_join_solict.part.7+0xa2/0xd0
addrconf_dad_work+0x500/0x980
process_one_work+0x3f5/0x7d0
worker_thread+0x61/0x6c0
kthread+0x1c3/0x1f0
ret_from_fork+0x35/0x40

Freed by task 2547073:
__kasan_slab_free+0x130/0x180
kfree+0x90/0x1b0
__i40e_del_filter+0xa3/0xf0 [i40e]
i40e_del_mac_filter+0xf3/0x130 [i40e]
i40e_addr_unsync+0x85/0xa0 [i40e]
__hw_addr_sync_dev+0x9d/0x210
i40e_set_rx_mode+0x6d/0xf0 [i40e]
__dev_set_rx_mode+0xfb/0x1f0
__dev_mc_del+0x69/0x80
igmp6_group_dropped+0x279/0x510
__ipv6_dev_mc_dec+0x174/0x220
addrconf_leave_solict.part.8+0xa2/0xd0
__ipv6_ifa_notify+0x4cd/0x570
ipv6_ifa_notify+0x58/0x80
ipv6_del_addr+0x259/0x4a0
inet6_addr_del+0x188/0x260
addrconf_del_ifaddr+0xcc/0x130
inet6_ioctl+0x152/0x190
sock_do_ioctl+0xd8/0x2b0
sock_ioctl+0x2e5/0x4c0
do_vfs_ioctl+0x14e/0xa80
ksys_ioctl+0x7c/0xa0
__x64_sys_ioctl+0x42/0x50
do_syscall_64+0x98/0x2c0
entry_SYSCALL_64_after_hwframe+0x65/0xca

Fixes: 41c445ff0f48 ("i40e: main driver core")
Signed-off-by: Di Zhu <zhudi2@xxxxxxxxxx>
Signed-off-by: Rui Zhang <zhangrui182@xxxxxxxxxx>
Tested-by: Gurucharan G <gurucharanx.g@xxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/intel/i40e/i40e_main.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -107,6 +107,24 @@ MODULE_VERSION(DRV_VERSION);

static struct workqueue_struct *i40e_wq;

+static void netdev_hw_addr_refcnt(struct i40e_mac_filter *f,
+ struct net_device *netdev, int delta)
+{
+ struct netdev_hw_addr *ha;
+
+ if (!f || !netdev)
+ return;
+
+ netdev_for_each_mc_addr(ha, netdev) {
+ if (ether_addr_equal(ha->addr, f->macaddr)) {
+ ha->refcount += delta;
+ if (ha->refcount <= 0)
+ ha->refcount = 1;
+ break;
+ }
+ }
+}
+
/**
* i40e_allocate_dma_mem_d - OS specific memory alloc for shared code
* @hw: pointer to the HW structure
@@ -2022,6 +2040,7 @@ static void i40e_undo_add_filter_entries
hlist_for_each_entry_safe(new, h, from, hlist) {
/* We can simply free the wrapper structure */
hlist_del(&new->hlist);
+ netdev_hw_addr_refcnt(new->f, vsi->netdev, -1);
kfree(new);
}
}
@@ -2369,6 +2388,10 @@ int i40e_sync_vsi_filters(struct i40e_vs
&tmp_add_list,
&tmp_del_list,
vlan_filters);
+
+ hlist_for_each_entry(new, &tmp_add_list, hlist)
+ netdev_hw_addr_refcnt(new->f, vsi->netdev, 1);
+
if (retval)
goto err_no_memory_locked;

@@ -2501,6 +2524,7 @@ int i40e_sync_vsi_filters(struct i40e_vs
if (new->f->state == I40E_FILTER_NEW)
new->f->state = new->state;
hlist_del(&new->hlist);
+ netdev_hw_addr_refcnt(new->f, vsi->netdev, -1);
kfree(new);
}
spin_unlock_bh(&vsi->mac_filter_hash_lock);