{"id":"CVE-2026-52925","title":"vrf: Fix a potential NPD when removing a port from a VRF","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nvrf: Fix a potential NPD when removing a port from a VRF\n\nRCU readers that identified a net device as a VRF port using\nnetif_is_l3_slave() assume that a subsequent call…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 2c022f582fd16a470df6ed9e7fb7e9fc48946d49","Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4","Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 468defa0b70902a22f4478c1207624bc1b31c124","Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 3db8d078f7f652379ee394132b169d304f6eb4c1","Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 8c2b792f04a3db97c9d8d2a45817e93f8884baf5","Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < a7a97f2303e63ede105c1d55ef53dc497364e11d","Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < d47204c127992da0c976ac9747070a575912e0fe","Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 2674d603a9e6970463b2b9ebcf8e31e90beae169","Linux 4.12"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:14:10.024799Z"},"published":"2026-06-24","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:23:49.718Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-52925","references":[{"url":"https://git.kernel.org/stable/c/2c022f582fd16a470df6ed9e7fb7e9fc48946d49"},{"url":"https://git.kernel.org/stable/c/4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4"},{"url":"https://git.kernel.org/stable/c/468defa0b70902a22f4478c1207624bc1b31c124"},{"url":"https://git.kernel.org/stable/c/3db8d078f7f652379ee394132b169d304f6eb4c1"},{"url":"https://git.kernel.org/stable/c/8c2b792f04a3db97c9d8d2a45817e93f8884baf5"},{"url":"https://git.kernel.org/stable/c/a7a97f2303e63ede105c1d55ef53dc497364e11d"},{"url":"https://git.kernel.org/stable/c/d47204c127992da0c976ac9747070a575912e0fe"},{"url":"https://git.kernel.org/stable/c/2674d603a9e6970463b2b9ebcf8e31e90beae169"}],"tags":["cve.org"],"epss":0.00114,"epssPercentile":0.01503,"ingestedAt":"2026-11-06T16:57:43.311Z","slug":"CVE-2026-52925","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nvrf: Fix a potential NPD when removing a port from a VRF\n\nRCU readers that identified a net device as a VRF port using\nnetif_is_l3_slave() assume that a subsequent call to\nnetdev_master_upper_dev_get_rcu() will return a VRF device. They then\ncontinue to dereference its l3mdev operations.\n\nThis assumption is not always correct and can result in a NPD [1]. There\nis no RCU synchronization when removing a port from a VRF, so it is\npossible for an RCU reader to see a new master device (e.g., a bridge)\nthat does not have l3mdev operations.\n\nFix by adding RCU synchronization after clearing the IFF_L3MDEV_SLAVE\nflag. Skip this synchronization when a net device is removed from a VRF\nas part of its deletion and when the VRF device itself is deleted. In\nthe latter case an RCU grace period will pass by the time RTNL is\nreleased.\n\n[1]\nBUG: kernel NULL pointer dereference, address: 0000000000000000\n[...]\nRIP: 0010:l3mdev_fib_table_rcu (net/l3mdev/l3mdev.c:181)\n[...]\nCall Trace:\n<TASK>\nl3mdev_fib_table_by_index (net/l3mdev/l3mdev.c:201 net/l3mdev/l3mdev.c:189)\n__inet_bind (net/ipv4/af_inet.c:499 (discriminator 3))\ninet_bind_sk (net/ipv4/af_inet.c:469)\n__sys_bind (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:1951 (discriminator 1))\n__x64_sys_bind (net/socket.c:1969 (discriminator 1) net/socket.c:1967 (discriminator 1) net/socket.c:1967 (discriminator 1))\ndo_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))\nentry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)\n\n## Affected\n\n- `Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 2c022f582fd16a470df6ed9e7fb7e9fc48946d49`\n- `Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4`\n- `Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 468defa0b70902a22f4478c1207624bc1b31c124`\n- `Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 3db8d078f7f652379ee394132b169d304f6eb4c1`\n- `Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 8c2b792f04a3db97c9d8d2a45817e93f8884baf5`\n- `Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < a7a97f2303e63ede105c1d55ef53dc497364e11d`\n- `Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < d47204c127992da0c976ac9747070a575912e0fe`\n- `Linux >= fdeea7be88b12742bfd50d9e19a06c0d2e702400 < 2674d603a9e6970463b2b9ebcf8e31e90beae169`\n- `Linux 4.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}