CVE-2025-21764: ndisc: use RCU protection in ndisc_alloc_skb()

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• linux linux kernel3.9 and later · before 5.4.291
• linux linux kernel5.5 and later · before 5.10.235
• linux linux kernel5.11 and later · before 5.15.179
• linux linux kernel5.16 and later · before 6.1.129
• linux linux kernel6.2 and later · before 6.6.79
• linux linux kernel6.7 and later · before 6.12.16
• linux linux kernel6.13 and later · before 6.13.4
• linux linux kernel6.14

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

• Linux Linux

  • 3.9affected
  • de09334b9326632bbf1a74bfd8b01866cbbf2f61 and later · before 96fc896d0e5b37c12808df797397fb16f3080879affected · git
  • de09334b9326632bbf1a74bfd8b01866cbbf2f61 and later · before c30893ef3d9cde8e7e8e4fd06b53d2c935bbccb1affected · git
  • de09334b9326632bbf1a74bfd8b01866cbbf2f61 and later · before b870256dd2a5648d5ed2f22316b3ac29a7e5ed63affected · git
  • de09334b9326632bbf1a74bfd8b01866cbbf2f61 and later · before 3c2d705f5adf5d860aaef90cb4211c0fde2ba66daffected · git
  • de09334b9326632bbf1a74bfd8b01866cbbf2f61 and later · before 9e0ec817eb41a55327a46cd3ce331a9868d60304affected · git
  • de09334b9326632bbf1a74bfd8b01866cbbf2f61 and later · before bbec88e4108e8d6fb468d3817fa652140a44ff28affected · git
  • de09334b9326632bbf1a74bfd8b01866cbbf2f61 and later · before cd1065f92eb7ff21b9ba5308a86f33d1670bf926affected · git
  • de09334b9326632bbf1a74bfd8b01866cbbf2f61 and later · before 628e6d18930bbd21f2d4562228afe27694f66da9affected · git
  • before 3.9not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Other highest-scoring records for the same primary product.

• CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
  90Now
• CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
  89Now
• CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
  85Now

Published before and after this one in the same product

• ← EarlierCVE-2025-21762Feb 27, 2025 · arp: use RCU protection in arp_xmit()
  32Monitor
• ← EarlierCVE-2025-21763Feb 27, 2025 · neighbour: use RCU protection in __neigh_notify()
  31Monitor
• Later →CVE-2025-21765Feb 27, 2025 · ipv6: use RCU protection in ip6_default_advmss()
  22Monitor

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1free(dev->buf);2/* ... another thread is still running ... */3process(dev->buf);

1lock(&dev->lock);2free(dev->buf);3dev->buf = NULL;4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.