NULL pointer dereference in Linux

CVE-2021-47619

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix queues reservation for XDP When XDP was configured on a system with large number of CPUs and X722 NIC there was a call trace with NULL pointer dereference. i40e 0000:87:00.0: failed to get tracking for 256 queues for VSI 0 err -12 i40e 0000:87:00.0: setup of MAIN VSI failed BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:i40e_xdp+0xea/0x1b0 [i40e] Call Trace: ? i40e_reconfig_rss_queues+0x130/0x130 [i40e] dev_xdp_install+0x61/0xe0 dev_xdp_attach+0x18a/0x4c0 dev_change_xdp_fd+0x1e6/0x220 do_setlink+0x616/0x1030 ? ahci_port_stop+0x80/0x80 ? ata_qc_issue+0x107/0x1e0 ? lock_timer_base+0x61/0x80 ? __mod_timer+0x202/0x380 rtnl_setlink+0xe5/0x170 ? bpf_lsm_binder_transaction+0x10/0x10 ? security_capable+0x36/0x50 rtnetlink_rcv_msg+0x121/0x350 ? rtnl_calcit.isra.0+0x100/0x100 netlink_rcv_skb+0x50/0xf0 netlink_unicast+0x1d3/0x2a0 netlink_sendmsg+0x22a/0x440 sock_sendmsg+0x5e/0x60 __sys_sendto+0xf0/0x160 ? __sys_getsockname+0x7e/0xc0 ? _copy_from_user+0x3c/0x80 ? __sys_setsockopt+0xc8/0x1a0 __x64_sys_sendto+0x20/0x30 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f83fa7a39e0 This was caused by PF queue pile fragmentation due to flow director VSI queue being placed right after main VSI. Because of this main VSI was not able to resize its queue allocation for XDP resulting in no queues allocated for main VSI when XDP was turned on. Fix this by always allocating last queue in PF queue pile for a flow director VSI.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (11.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 11.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-47619: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

  • Linux — versions 41c445ff0f482bb6e6b72dcee9e598e20575f743, 3.12, 0
  • Linux Kernel — versions 5.17

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47619?
CVE-2021-47619 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2024-06-20.
How severe is CVE-2021-47619?
Medium severity. CVSS v3 base score is 5.5 out of 10.