high CVSS 7.8

CVE-2022-49127·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: ref_tracker: implement use-after-free detection Whenever ref_tracker_dir_init() is called, mark the struct ref_tracker_dir as dead. Test the dead status from ref_tracker_alloc() and ref_tracker_free() This should detect buggy dev_put()/dev_hold() happening too late in netdevice dismantle process.

Severity
high
Software
Kernel
Fixed in
5.17.3
Published
2025-02-26

Affected versions

From: 5.17

Until: 5.17.3

Fixed in: 5.17.3

How to fix this CVE

Update your Linux kernel to version 5.17.3 or later to address a use-after-free detection flaw in the ref_tracker subsystem. This vulnerability can allow local authenticated users to trigger kernel memory safety issues during network device cleanup operations. Apply the patch immediately, particularly if your systems run containerized workloads or handle frequent network interface creation/destruction cycles.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check your current kernel version by running: uname -r | grep -oP '\d+\.\d+\.\d+'
  2. Step 2: Compare your kernel version against 5.17.3 — versions 5.17.0 through 5.17.2 are vulnerable; verify if your system uses the affected range with: cat /proc/version
  3. Step 3: Search kernel logs for ref_tracker related warnings or use-after-free detections: sudo dmesg | grep -i 'ref_tracker\|use-after-free'
  4. Step 4: After patching, verify the update applied successfully by rebooting and re-running: uname -r to confirm kernel version is 5.17.3 or higher

FAQ

What is CVE-2022-49127?

CVE-2022-49127 is a use-after-free detection vulnerability in the Linux kernel's ref_tracker subsystem that fails to properly mark reference tracking structures as dead during device dismantling, potentially allowing local authenticated attackers to trigger memory safety violations.

Is CVE-2022-49127 being actively exploited?

No, according to CISA's Known Exploited Vulnerabilities catalog, CVE-2022-49127 is not being actively exploited in the wild, and no public exploits are currently available.

What versions of Kernel are affected by CVE-2022-49127?

Linux kernel versions 5.17.0 through 5.17.2 are affected; version 5.17.3 and later include the fix.

How do I check if my server is vulnerable to CVE-2022-49127?

Run: uname -r and verify the output; if it shows 5.17.0, 5.17.1, or 5.17.2, your system is vulnerable and requires immediate kernel update.

Does Defensia detect CVE-2022-49127?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2022-49127 will appear in your dashboard with remediation steps.

Related Kernel CVEs

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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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