{"id":"CVE-2026-52925","state":"PUBLISHED","title":"vrf: Fix a potential NPD when removing a port from a VRF","description":"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<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)","publishedAt":"2026-06-24T07:14:19.351Z","updatedAt":"2026-06-24T07:14:19.351Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"2c022f582fd16a470df6ed9e7fb7e9fc48946d49","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"468defa0b70902a22f4478c1207624bc1b31c124","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"3db8d078f7f652379ee394132b169d304f6eb4c1","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"8c2b792f04a3db97c9d8d2a45817e93f8884baf5","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"a7a97f2303e63ede105c1d55ef53dc497364e11d","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"d47204c127992da0c976ac9747070a575912e0fe","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"2674d603a9e6970463b2b9ebcf8e31e90beae169","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vrf.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.12","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vrf.c"]}],"references":["https://git.kernel.org/stable/c/2c022f582fd16a470df6ed9e7fb7e9fc48946d49","https://git.kernel.org/stable/c/4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4","https://git.kernel.org/stable/c/468defa0b70902a22f4478c1207624bc1b31c124","https://git.kernel.org/stable/c/3db8d078f7f652379ee394132b169d304f6eb4c1","https://git.kernel.org/stable/c/8c2b792f04a3db97c9d8d2a45817e93f8884baf5","https://git.kernel.org/stable/c/a7a97f2303e63ede105c1d55ef53dc497364e11d","https://git.kernel.org/stable/c/d47204c127992da0c976ac9747070a575912e0fe","https://git.kernel.org/stable/c/2674d603a9e6970463b2b9ebcf8e31e90beae169"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/52xxx/CVE-2026-52925.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52925","state":"PUBLISHED","datePublished":"2026-06-24T07:14:19.351Z","dateUpdated":"2026-06-24T07:14:19.351Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.368Z"},"containers":{"cna":{"title":"vrf: Fix a potential NPD when removing a port from a VRF","descriptions":[{"lang":"en","value":"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<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)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"2c022f582fd16a470df6ed9e7fb7e9fc48946d49","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"468defa0b70902a22f4478c1207624bc1b31c124","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"3db8d078f7f652379ee394132b169d304f6eb4c1","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"8c2b792f04a3db97c9d8d2a45817e93f8884baf5","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"a7a97f2303e63ede105c1d55ef53dc497364e11d","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"d47204c127992da0c976ac9747070a575912e0fe","versionType":"git"},{"version":"fdeea7be88b12742bfd50d9e19a06c0d2e702400","status":"affected","lessThan":"2674d603a9e6970463b2b9ebcf8e31e90beae169","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vrf.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.12","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vrf.c"]}],"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-06-24T07:14:19.351Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}