medium CVSS 5.5

CVE-2022-48720·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: net: macsec: Fix offload support for NETDEV_UNREGISTER event Current macsec netdev notify handler handles NETDEV_UNREGISTER event by releasing relevant SW resources only, this causes resources leak in case of macsec HW offload, as the underlay driver was not notified to clean it's macsec offload resources. Fix by calling the underlay driver to clean it's relevant resources by moving offload handling from macsec_dellink() to macsec_common_dellink() when handling NETDEV_UNREGISTER event.

Severity
medium
Software
Kernel
Fixed in
5.16.8
Published
2024-06-20

Affected versions

From: 5.16

Until: 5.16.8

Fixed in: 5.16.8

How to fix this CVE

Update your Linux kernel to version 5.16.8 or later to remediate CVE-2022-48720. This vulnerability affects macsec (MAC Security) hardware offload functionality, where network device unregistration events were not properly notifying underlay drivers to release offload resources, causing memory leaks. Apply the kernel security patch through your distribution's package manager and reboot your system to complete remediation.

sudo dnf update kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Check installed kernel version: uname -r | grep -E '^5\.16\.[0-7]($|[^0-9])'
  2. Verify macsec module is loaded: lsmod | grep macsec
  3. Check for active macsec interfaces with hardware offload: ip macsec show | grep -i offload
  4. Confirm kernel patch level: cat /proc/version and verify it matches 5.16.8 or later

FAQ

What is CVE-2022-48720?

CVE-2022-48720 is a kernel vulnerability in macsec hardware offload handling where network device unregistration fails to notify underlying drivers to properly clean up offload resources, resulting in memory and resource leaks on systems using macsec security features.

Is CVE-2022-48720 being actively exploited?

No, CVE-2022-48720 is not listed on CISA's Known Exploited Vulnerabilities catalog and no public exploits are available. This is a resource leak vulnerability that requires local access and macsec hardware offload configuration.

What versions of Kernel are affected by CVE-2022-48720?

Linux kernel versions 5.16 through 5.16.7 are affected. The vulnerability is patched in kernel version 5.16.8 and later.

How do I check if my server is vulnerable to CVE-2022-48720?

Run 'uname -r' and check if the output matches 5.16.0 through 5.16.7. If macsec is not in use (verify with 'lsmod | grep macsec'), your system is not practically vulnerable to exploitation from this issue.

Does Defensia detect CVE-2022-48720?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Linux kernel is installed on a monitored server, CVE-2022-48720 will appear in your dashboard with remediation steps.

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CVE-2026-63993CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu() skb_tunnel_check_pmtu() can change skb->head. Reusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF. Use instead ip_hdr(skb) as done in drivers/net/bareudp.c and drivers/net/geneve.c. Found by Sashiko.
CVE-2026-43501CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ipv6: rpl: reserve mac_len headroom when recompressed SRH grows ipv6_rpl_srh_rcv() decompresses an RFC 6554 Source Routing Header, swaps the next segment into ipv6_hdr->daddr, recompresses, then pulls the old header and pushes the new one plus the IPv6 header back. The recompressed header can be larger than the received one when the swap reduces the common-prefix length the segments share with daddr (CmprI=0, CmprE>0, seg[0][0] != daddr[0] gives the maximum +8 bytes). pskb_expand_head() was gated on segments_left == 0, so on earlier segments the push consumed unchecked headroom. Once skb_push() leaves fewer than skb->mac_len bytes in front of data, skb_mac_header_rebuild()'s call to: skb_set_mac_header(skb, -skb->mac_len); will store (data - head) - mac_len into the u16 mac_header field, which wraps to ~65530, and the following memmove() writes mac_len bytes ~64KiB past skb->head. A single AF_INET6/SOCK_RAW/IPV6_HDRINCL packet over lo with a two segment type-3 SRH (CmprI=0, CmprE=15) reaches headroom 8 after one pass; KASAN reports a 14-byte OOB write in ipv6_rthdr_rcv. Fix this by expanding the head whenever the remaining room is less than the push size plus mac_len, and request that much extra so the rebuilt MAC header fits afterwards.
CVE-2026-64216CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages() netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.

References

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