Double Free Affecting kernel package, versions <0:4.14.262-200.489.amzn2
Threat Intelligence
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Test your applications- Snyk IDSNYK-AMZN2-KERNEL-7678794
- published14 Aug 2024
- disclosed19 Jun 2024
Introduced: 19 Jun 2024
CVE-2021-47589 (opens in a new tab)How to fix?
Upgrade Amazon-Linux:2 kernel to version 0:4.14.262-200.489.amzn2 or higher.
This issue was patched in ALAS2-2022-1749.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel package and not the kernel package as distributed by Amazon-Linux.
See How to fix? for Amazon-Linux:2 relevant fixed versions and status.
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
References
- http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-47589
- https://git.kernel.org/stable/c/74a16e062b23332d8db017ff4a41e16279c44411
- https://git.kernel.org/stable/c/79d9b092035dcdbe636b70433149df9cc6db1e49
- https://git.kernel.org/stable/c/8addba6cab94ce01686ea2e80ed1530f9dc33a9a
- https://git.kernel.org/stable/c/8d0c927a9fb2b4065230936b77b54f857a3754fc
- https://git.kernel.org/stable/c/944b8be08131f5faf2cd2440aa1c24a39a163a54
- https://git.kernel.org/stable/c/b6d335a60dc624c0d279333b22c737faa765b028
- https://git.kernel.org/stable/c/cc9b655bb84f1be283293dfea94dff9a31b106ac
- https://git.kernel.org/stable/c/ffe1695b678729edec04037e691007900a2b2beb