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| author | jinyiting <jinyiting@huawei.com> | 2021-04-21 10:38:21 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-04-21 23:42:19 +0200 |
| commit | 83d686a6822322c4981b745dc1d7185f1f40811b (patch) | |
| tree | ee8a443dff5e504b1c87e8ab24fa9d68ed73a746 /drivers/net/bonding/bond_main.c | |
| parent | net: qrtr: Avoid potential use after free in MHI send (diff) | |
| download | linux-83d686a6822322c4981b745dc1d7185f1f40811b.tar.xz linux-83d686a6822322c4981b745dc1d7185f1f40811b.zip | |
bonding: 3ad: Fix the conflict between bond_update_slave_arr and the state machine
The bond works in mode 4, and performs down/up operations on the bond
that is normally negotiated. The probability of bond-> slave_arr is NULL
Test commands:
ifconfig bond1 down
ifconfig bond1 up
The conflict occurs in the following process：
__dev_open (CPU A)
--bond_open
--queue_delayed_work(bond->wq,&bond->ad_work,0);
--bond_update_slave_arr
--bond_3ad_get_active_agg_info
ad_work(CPU B)
--bond_3ad_state_machine_handler
--ad_agg_selection_logic
ad_work runs on cpu B. In the function ad_agg_selection_logic, all
agg->is_active will be cleared. Before the new active aggregator is
selected on CPU B, bond_3ad_get_active_agg_info failed on CPU A,
bond->slave_arr will be set to NULL. The best aggregator in
ad_agg_selection_logic has not changed, no need to update slave arr.
The conflict occurred in that ad_agg_selection_logic clears
agg->is_active under mode_lock, but bond_open -> bond_update_slave_arr
is inspecting agg->is_active outside the lock.
Also, bond_update_slave_arr is normal for potential sleep when
allocating memory, so replace the WARN_ON with a call to might_sleep.
Signed-off-by: jinyiting <jinyiting@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/bonding/bond_main.c')
| -rw-r--r-- | drivers/net/bonding/bond_main.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 74cbbb22470b..83ef62db6285 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -4391,9 +4391,7 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave) int agg_id = 0; int ret = 0; -#ifdef CONFIG_LOCKDEP - WARN_ON(lockdep_is_held(&bond->mode_lock)); -#endif + might_sleep(); usable_slaves = kzalloc(struct_size(usable_slaves, arr, bond->slave_cnt), GFP_KERNEL); @@ -4406,7 +4404,9 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave) if (BOND_MODE(bond) == BOND_MODE_8023AD) { struct ad_info ad_info; + spin_lock_bh(&bond->mode_lock); if (bond_3ad_get_active_agg_info(bond, &ad_info)) { + spin_unlock_bh(&bond->mode_lock); pr_debug("bond_3ad_get_active_agg_info failed\n"); /* No active aggragator means it's not safe to use * the previous array. @@ -4414,6 +4414,7 @@ int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave) bond_reset_slave_arr(bond); goto out; } + spin_unlock_bh(&bond->mode_lock); agg_id = ad_info.aggregator_id; } bond_for_each_slave(bond, slave, iter) { |