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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-52925

vrf: Fix a potential NPD when removing a port from a VRF

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Status
Published
Published
Updated
Assigning organization
Linux

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)

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • fdeea7be88b12742bfd50d9e19a06c0d2e702400 to < 2c022f582fd16a470df6ed9e7fb7e9fc48946d49affected
  • fdeea7be88b12742bfd50d9e19a06c0d2e702400 to < 4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4affected
  • fdeea7be88b12742bfd50d9e19a06c0d2e702400 to < 468defa0b70902a22f4478c1207624bc1b31c124affected
  • fdeea7be88b12742bfd50d9e19a06c0d2e702400 to < 3db8d078f7f652379ee394132b169d304f6eb4c1affected
  • fdeea7be88b12742bfd50d9e19a06c0d2e702400 to < 8c2b792f04a3db97c9d8d2a45817e93f8884baf5affected
  • fdeea7be88b12742bfd50d9e19a06c0d2e702400 to < a7a97f2303e63ede105c1d55ef53dc497364e11daffected
  • fdeea7be88b12742bfd50d9e19a06c0d2e702400 to < d47204c127992da0c976ac9747070a575912e0feaffected
  • fdeea7be88b12742bfd50d9e19a06c0d2e702400 to < 2674d603a9e6970463b2b9ebcf8e31e90beae169affected

Linux Linux

Default version status: affected

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

References