{"id":"CVE-2026-52925","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-52925","generatedAt":"2026-10-28T01:42:49.425Z","title":"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…","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)","published":"2026-06-24T08:16:23.000Z","lastModified":"2026-07-08T15:29:08.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-476"],"affected":["linux/linux kernel"],"epss":{"score":0.00114,"percentile":0.0148,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.11%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/2674d603a9e6970463b2b9ebcf8e31e90beae169","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2c022f582fd16a470df6ed9e7fb7e9fc48946d49","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3db8d078f7f652379ee394132b169d304f6eb4c1","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/468defa0b70902a22f4478c1207624bc1b31c124","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4ab6fc60ed5a0344b60711b09bff1dc238d8d6a4","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8c2b792f04a3db97c9d8d2a45817e93f8884baf5","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a7a97f2303e63ede105c1d55ef53dc497364e11d","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d47204c127992da0c976ac9747070a575912e0fe","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-52925","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}