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authorYevhen Orlov <yevhen.orlov@plvision.eu>2022-06-29 04:29:14 +0300
committerJakub Kicinski <kuba@kernel.org>2022-06-29 20:52:40 -0700
commit050133e1aa2cb49bb17be847d48a4431598ef562 (patch)
tree993797de160b83ac2a145dd406eb8ff384be06e1 /drivers/net/bonding
parent4e43e64d0f1332fcc503babad4dc31aead7131ca (diff)
net: bonding: fix use-after-free after 802.3ad slave unbind
commit 0622cab0341c ("bonding: fix 802.3ad aggregator reselection"), resolve case, when there is several aggregation groups in the same bond. bond_3ad_unbind_slave will invalidate (clear) aggregator when __agg_active_ports return zero. So, ad_clear_agg can be executed even, when num_of_ports!=0. Than bond_3ad_unbind_slave can be executed again for, previously cleared aggregator. NOTE: at this time bond_3ad_unbind_slave will not update slave ports list, because lag_ports==NULL. So, here we got slave ports, pointing to freed aggregator memory. Fix with checking actual number of ports in group (as was before commit 0622cab0341c ("bonding: fix 802.3ad aggregator reselection") ), before ad_clear_agg(). The KASAN logs are as follows: [ 767.617392] ================================================================== [ 767.630776] BUG: KASAN: use-after-free in bond_3ad_state_machine_handler+0x13dc/0x1470 [ 767.638764] Read of size 2 at addr ffff00011ba9d430 by task kworker/u8:7/767 [ 767.647361] CPU: 3 PID: 767 Comm: kworker/u8:7 Tainted: G O 5.15.11 #15 [ 767.655329] Hardware name: DNI AmazonGo1 A7040 board (DT) [ 767.660760] Workqueue: lacp_1 bond_3ad_state_machine_handler [ 767.666468] Call trace: [ 767.668930] dump_backtrace+0x0/0x2d0 [ 767.672625] show_stack+0x24/0x30 [ 767.675965] dump_stack_lvl+0x68/0x84 [ 767.679659] print_address_description.constprop.0+0x74/0x2b8 [ 767.685451] kasan_report+0x1f0/0x260 [ 767.689148] __asan_load2+0x94/0xd0 [ 767.692667] bond_3ad_state_machine_handler+0x13dc/0x1470 Fixes: 0622cab0341c ("bonding: fix 802.3ad aggregator reselection") Co-developed-by: Maksym Glubokiy <maksym.glubokiy@plvision.eu> Signed-off-by: Maksym Glubokiy <maksym.glubokiy@plvision.eu> Signed-off-by: Yevhen Orlov <yevhen.orlov@plvision.eu> Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com> Link: https://lore.kernel.org/r/20220629012914.361-1-yevhen.orlov@plvision.eu Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/bonding')
-rw-r--r--drivers/net/bonding/bond_3ad.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index a86b1f71762e..d7fb33c078e8 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -2228,7 +2228,8 @@ void bond_3ad_unbind_slave(struct slave *slave)
temp_aggregator->num_of_ports--;
if (__agg_active_ports(temp_aggregator) == 0) {
select_new_active_agg = temp_aggregator->is_active;
- ad_clear_agg(temp_aggregator);
+ if (temp_aggregator->num_of_ports == 0)
+ ad_clear_agg(temp_aggregator);
if (select_new_active_agg) {
slave_info(bond->dev, slave->dev, "Removing an active aggregator\n");
/* select new active aggregator */