CVE-2026-52925vrf: Fix a potential NPD when removing a port from a VRF

Description

In the Linux kernel, the following vulnerability has been resolved: vrf: Fix a potential NPD when removing a port from a VRF RCU readers that identified a net device as a VRF port using netif_is_l3_slave() assume that a subsequent call to netdev_master_upper_dev_get_rcu() will return a VRF device. They then continue to dereference its l3mdev operations. This assumption is not always correct and can result in a NPD [1]. There is no RCU synchronization when removing a port from a VRF, so it is possible for an RCU reader to see a new master device (e.g., a bridge) that does not have l3mdev operations. Fix by adding RCU synchronization after clearing the IFF_L3MDEV_SLAVE flag. Skip this synchronization when a net device is removed from a VRF as part of its deletion and when the VRF device itself is deleted. In the latter case an RCU grace period will pass by the time RTNL is released. [1] BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] RIP: 0010:l3mdev_fib_table_rcu (net/l3mdev/l3mdev.c:181) [...] Call Trace: <TASK> l3mdev_fib_table_by_index (net/l3mdev/l3mdev.c:201 net/l3mdev/l3mdev.c:189) __inet_bind (net/ipv4/af_inet.c:499 (discriminator 3)) inet_bind_sk (net/ipv4/af_inet.c:469) __sys_bind (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:1951 (discriminator 1)) __x64_sys_bind (net/socket.c:1969 (discriminator 1) net/socket.c:1967 (discriminator 1) net/socket.c:1967 (discriminator 1)) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Timeline

Scores

EPSS (exploitation in 30 days)

0.11% · top 98% of all CVEs (12 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Affected products

• Linux · Linux

  • affected fdeea7be88b12742bfd50d9e19a06c0d2e702400 – < 2c022f582fd16a470df6ed9e7fb7e9fc48946d49
  • affected fdeea7be88b12742bfd50d9e19a06c0d2e702400 – < 4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4
  • affected fdeea7be88b12742bfd50d9e19a06c0d2e702400 – < 468defa0b70902a22f4478c1207624bc1b31c124
  • affected fdeea7be88b12742bfd50d9e19a06c0d2e702400 – < 3db8d078f7f652379ee394132b169d304f6eb4c1
  • affected fdeea7be88b12742bfd50d9e19a06c0d2e702400 – < 8c2b792f04a3db97c9d8d2a45817e93f8884baf5
  • affected fdeea7be88b12742bfd50d9e19a06c0d2e702400 – < a7a97f2303e63ede105c1d55ef53dc497364e11d
  • affected fdeea7be88b12742bfd50d9e19a06c0d2e702400 – < d47204c127992da0c976ac9747070a575912e0fe
  • affected fdeea7be88b12742bfd50d9e19a06c0d2e702400 – < 2674d603a9e6970463b2b9ebcf8e31e90beae169

• Linux · Linux

  • affected 4.12
  • unaffected < 4.12
  • unaffected 5.10.258 – ≤ 5.10.*
  • unaffected 5.15.209 – ≤ 5.15.*
  • unaffected 6.1.175 – ≤ 6.1.*
  • unaffected 6.6.141 – ≤ 6.6.*
  • unaffected 6.12.91 – ≤ 6.12.*
  • unaffected 6.18.33 – ≤ 6.18.*
  • unaffected 7.0.10 – ≤ 7.0.*
  • unaffected 7.1 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-38728 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-52925](https://cveledger.app/badge/CVE-2026-52925.svg)](https://cveledger.app/cve/CVE-2026-52925)

Record last updated 6 Nov 2026, 16:23 UTC.