CVE-2021-47589

In the Linux kernel, the following vulnerability has been resolved: igbvf:
fix double free in igbvf_probe In igbvf_probe, if register_netdev()
fails, the program will go to label err_hw_init, and then to label
err_ioremap. In free_netdev() which is just below label err_ioremap, there
is list_for_each_entry_safe and netif_napi_del which aims to delete all
entries in dev->napi_list. The program has added an entry
adapter->rx_ring->napi which is added by netif_napi_add in
igbvf_alloc_queues(). However, adapter->rx_ring has been freed below label
err_hw_init. So this a UAF. In terms of how to patch the problem, we can
refer to igbvf_remove() and delete the entry before adapter->rx_ring. The
KASAN logs are as follows: [ 35.126075] BUG: KASAN: use-after-free in
free_netdev+0x1fd/0x450 [ 35.127170] Read of size 8 at addr
ffff88810126d990 by task modprobe/366 [ 35.128360] [ 35.128643] CPU: 1 PID:
366 Comm: modprobe Not tainted 5.15.0-rc2+ #14 [ 35.129789] Hardware name:
QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 [ 35.131749] Call
Trace: [ 35.132199] dump_stack_lvl+0x59/0x7b [ 35.132865]
print_address_description+0x7c/0x3b0 [ 35.133707] ? free_netdev+0x1fd/0x450
[ 35.134378] __kasan_report+0x160/0x1c0 [ 35.135063] ?
free_netdev+0x1fd/0x450 [ 35.135738] kasan_report+0x4b/0x70 [ 35.136367]
free_netdev+0x1fd/0x450 [ 35.137006] igbvf_probe+0x121d/0x1a10 [igbvf] [
35.137808] ? igbvf_vlan_rx_add_vid+0x100/0x100 [igbvf] [ 35.138751]
local_pci_probe+0x13c/0x1f0 [ 35.139461] pci_device_probe+0x37e/0x6c0 [
35.165526] [ 35.165806] Allocated by task 366: [ 35.166414]
____kasan_kmalloc+0xc4/0xf0 [ 35.167117]
foo_kmem_cache_alloc_trace+0x3c/0x50 [igbvf] [ 35.168078]
igbvf_probe+0x9c5/0x1a10 [igbvf] [ 35.168866] local_pci_probe+0x13c/0x1f0 [
35.169565] pci_device_probe+0x37e/0x6c0 [ 35.179713] [ 35.179993] Freed by
task 366: [ 35.180539] kasan_set_track+0x4c/0x80 [ 35.181211]
kasan_set_free_info+0x1f/0x40 [ 35.181942] ____kasan_slab_free+0x103/0x140
[ 35.182703] kfree+0xe3/0x250 [ 35.183239] igbvf_probe+0x1173/0x1a10
[igbvf] [ 35.184040] local_pci_probe+0x13c/0x1f0