{"id":"CVE-2026-52925","summary":"vrf: Fix a potential NPD when removing a port from a VRF","details":"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 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\u003cTASK\u003e\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)","modified":"2026-07-10T03:54:12.959181668Z","published":"2026-06-24T07:14:19.351Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52925.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2674d603a9e6970463b2b9ebcf8e31e90beae169"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2c022f582fd16a470df6ed9e7fb7e9fc48946d49"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3db8d078f7f652379ee394132b169d304f6eb4c1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/468defa0b70902a22f4478c1207624bc1b31c124"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8c2b792f04a3db97c9d8d2a45817e93f8884baf5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a7a97f2303e63ede105c1d55ef53dc497364e11d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d47204c127992da0c976ac9747070a575912e0fe"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52925.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52925"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"fdeea7be88b12742bfd50d9e19a06c0d2e702400"},{"fixed":"2c022f582fd16a470df6ed9e7fb7e9fc48946d49"},{"fixed":"4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4"},{"fixed":"468defa0b70902a22f4478c1207624bc1b31c124"},{"fixed":"3db8d078f7f652379ee394132b169d304f6eb4c1"},{"fixed":"8c2b792f04a3db97c9d8d2a45817e93f8884baf5"},{"fixed":"a7a97f2303e63ede105c1d55ef53dc497364e11d"},{"fixed":"d47204c127992da0c976ac9747070a575912e0fe"},{"fixed":"2674d603a9e6970463b2b9ebcf8e31e90beae169"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52925.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.12.0"},{"fixed":"5.10.258"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.209"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.141"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.91"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.33"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52925.json"}}],"schema_version":"1.7.5"}