CVE-2021-47589

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