netif_receive_skb_list_internal() could call enqueue_to_backlog() to put
some skb to softnet_data.input_pkt_queue and then in
ip_route_input_slow(), it allocates a dst_entry to be used in
skb_dst_set(). Later,
cleanup_net
default_device_exit_batch
unregister_netdevice_many
rollback_registered_many
flush_all_backlogs
will call flush_backlog() for all CPUs which would call kfree_skb() for
each skb on the input_pkt_queue without calling skb_dst_drop() first.
unreferenced object 0xffff97008e4c4040 (size 176):
comm "softirq", pid 0, jiffies 4295173845 (age 32012.550s)
hex dump (first 32 bytes):
00 d0 a5 74 04 97 ff ff 40 72 1a 96 ff ff ff ff ...t....@r......
c1 a3 c5 95 ff ff ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000030483fae>] kmem_cache_alloc+0x184/0x430
[<000000007ae17545>] dst_alloc+0x8e/0x128
[<000000001efe9a1f>] rt_dst_alloc+0x6f/0x1e0
rt_dst_alloc at net/ipv4/route.c:1628
[<00000000e67d4dac>] ip_route_input_rcu+0xdfe/0x1640
ip_route_input_slow at net/ipv4/route.c:2218
(inlined by) ip_route_input_rcu at net/ipv4/route.c:2348
[<000000009f30cbc0>] ip_route_input_noref+0xab/0x1a0
[<000000004f53bd04>] arp_process+0x83a/0xf50
arp_process at net/ipv4/arp.c:813 (discriminator 1)
[<0000000061fd547d>] arp_rcv+0x276/0x330
[<0000000007dbfa7a>] __netif_receive_skb_list_core+0x4d2/0x500
[<0000000062d5f6d2>] netif_receive_skb_list_internal+0x4cb/0x7d0
[<000000002baa2b74>] gro_normal_list+0x55/0xc0
[<0000000093d04885>] napi_complete_done+0xea/0x350
[<00000000467dd088>] tg3_poll_msix+0x174/0x310 [tg3]
[<00000000498af7d9>] net_rx_action+0x278/0x890
[<000000001e81d7e6>] __do_softirq+0xd9/0x589
[<00000000087ee354>] irq_exit+0xa2/0xc0
[<000000001c4db0cd>] do_IRQ+0x87/0x180
Signed-off-by: Qian Cai <c...@lca.pw>
---
net/core/dev.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/core/dev.c b/net/core/dev.c
index 522288177bbd..b898cd3036da 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5496,6 +5496,7 @@ static void flush_backlog(struct work_struct *work)
skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
if (skb->dev->reg_state == NETREG_UNREGISTERING) {
__skb_unlink(skb, &sd->input_pkt_queue);
+ skb_dst_drop(skb);
kfree_skb(skb);
input_queue_head_incr(sd);
}
--
2.21.0 (Apple Git-122.2)
