CVE-2021-47589

CVE-2021-47589 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-415.

Key facts

Description

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

Frequently asked questions

What is 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
How severe is CVE-2021-47589?
CVE-2021-47589 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-47589 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47589?
CVE-2021-47589 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-47589?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2021-47589 have an EU (EUVD) identifier?
Yes. CVE-2021-47589 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34591.
When was CVE-2021-47589 published?
CVE-2021-47589 was published on 2024-06-19 and last updated on 2026-06-17.

References

Affected products (1)

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