2.8 KiB
CVE-2021-47589
Description
In the Linux kernel, the following vulnerability has been resolved:igbvf: fix double free in igbvf_probeIn igbvf_probe, if register_netdev() fails, the program will go tolabel err_hw_init, and then to label err_ioremap. In free_netdev() whichis just below label err_ioremap, there is list_for_each_entry_safe andnetif_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 bynetif_napi_add in igbvf_alloc_queues(). However, adapter->rx_ring hasbeen freed below label err_hw_init. So this a UAF.In terms of how to patch the problem, we can refer to igbvf_remove() anddelete 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
POC
Reference
No PoCs from references.