{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38470", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.020Z", "datePublished": "2025-07-28T11:21:32.002Z", "dateUpdated": "2026-08-05T12:02:09.041Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:02:09.041Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime\n\nAssuming the \"rx-vlan-filter\" feature is enabled on a net device, the\n8021q module will automatically add or remove VLAN 0 when the net device\nis put administratively up or down, respectively. There are a couple of\nproblems with the above scheme.\n\nThe first problem is a memory leak that can happen if the \"rx-vlan-filter\"\nfeature is disabled while the device is running:\n\n # ip link add bond1 up type bond mode 0\n # ethtool -K bond1 rx-vlan-filter off\n # ip link del dev bond1\n\nWhen the device is put administratively down the \"rx-vlan-filter\"\nfeature is disabled, so the 8021q module will not remove VLAN 0 and the\nmemory will be leaked [1].\n\nAnother problem that can happen is that the kernel can automatically\ndelete VLAN 0 when the device is put administratively down despite not\nadding it when the device was put administratively up since during that\ntime the \"rx-vlan-filter\" feature was disabled. null-ptr-unref or\nbug_on[2] will be triggered by unregister_vlan_dev() for refcount\nimbalance if toggling filtering during runtime:\n\n$ ip link add bond0 type bond mode 0\n$ ip link add link bond0 name vlan0 type vlan id 0 protocol 802.1q\n$ ethtool -K bond0 rx-vlan-filter off\n$ ifconfig bond0 up\n$ ethtool -K bond0 rx-vlan-filter on\n$ ifconfig bond0 down\n$ ip link del vlan0\n\nRoot cause is as below:\nstep1: add vlan0 for real_dev, such as bond, team.\nregister_vlan_dev\n vlan_vid_add(real_dev,htons(ETH_P_8021Q),0) //refcnt=1\nstep2: disable vlan filter feature and enable real_dev\nstep3: change filter from 0 to 1\nvlan_device_event\n vlan_filter_push_vids\n ndo_vlan_rx_add_vid //No refcnt added to real_dev vlan0\nstep4: real_dev down\nvlan_device_event\n vlan_vid_del(dev, htons(ETH_P_8021Q), 0); //refcnt=0\n vlan_info_rcu_free //free vlan0\nstep5: delete vlan0\nunregister_vlan_dev\n BUG_ON(!vlan_info); //vlan_info is null\n\nFix both problems by noting in the VLAN info whether VLAN 0 was\nautomatically added upon NETDEV_UP and based on that decide whether it\nshould be deleted upon NETDEV_DOWN, regardless of the state of the\n\"rx-vlan-filter\" feature.\n\n[1]\nunreferenced object 0xffff8880068e3100 (size 256):\n comm \"ip\", pid 384, jiffies 4296130254\n hex dump (first 32 bytes):\n 00 20 30 0d 80 88 ff ff 00 00 00 00 00 00 00 00 . 0.............\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\n backtrace (crc 81ce31fa):\n __kmalloc_cache_noprof+0x2b5/0x340\n vlan_vid_add+0x434/0x940\n vlan_device_event.cold+0x75/0xa8\n notifier_call_chain+0xca/0x150\n __dev_notify_flags+0xe3/0x250\n rtnl_configure_link+0x193/0x260\n rtnl_newlink_create+0x383/0x8e0\n __rtnl_newlink+0x22c/0xa40\n rtnl_newlink+0x627/0xb00\n rtnetlink_rcv_msg+0x6fb/0xb70\n netlink_rcv_skb+0x11f/0x350\n netlink_unicast+0x426/0x710\n netlink_sendmsg+0x75a/0xc20\n __sock_sendmsg+0xc1/0x150\n ____sys_sendmsg+0x5aa/0x7b0\n ___sys_sendmsg+0xfc/0x180\n\n[2]\nkernel BUG at net/8021q/vlan.c:99!\nOops: invalid opcode: 0000 [#1] SMP KASAN PTI\nCPU: 0 UID: 0 PID: 382 Comm: ip Not tainted 6.16.0-rc3 #61 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996),\nBIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014\nRIP: 0010:unregister_vlan_dev (net/8021q/vlan.c:99 (discriminator 1))\nRSP: 0018:ffff88810badf310 EFLAGS: 00010246\nRAX: 0000000000000000 RBX: ffff88810da84000 RCX: ffffffffb47ceb9a\nRDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88810e8b43c8\nRBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff6cefe80\nR10: ffffffffb677f407 R11: ffff88810badf3c0 R12: ffff88810e8b4000\nR13: 0000000000000000 R14: ffff88810642a5c0 R15: 000000000000017e\nFS: 00007f1ff68c20c0(0000) GS:ffff888163a24000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f1ff5dad240 CR3: 0000000107e56000 CR4: 00000000000006f0\nCall Trace:\n user_ns, CAP_NET_ADMIN) — so an unprivileged user obtains them via `unshare -Urn`, and bonding/team devices with a toggleable NETIF_F_HW_VLAN_CTAG_FILTER can be created entirely inside that namespace.\nUI:N - The attacker performs every step of the sequence themselves within their own network namespace; no victim action or cooperation is required.\nS:U - The corruption and its consequences are confined to the kernel's own memory and networking state, with no crossing into a different security authority such as a hypervisor or IOMMU boundary.\nC:H - The premature free of vlan_info leaves an orphaned GARP/MRP applicant whose periodic timer reads a freed struct net_device (mtu, needed_headroom) to size and populate skbs that are then transmitted, disclosing reclaimed kernel heap contents; per kernel scoring practice a use-after-free is scored High.\nI:H - The leaked applicant timer drives dev_queue_xmit() on a freed net_device, dereferencing netdev_ops function pointers from memory the attacker can heap-spray into during the ~250 ms timer window, yielding control-flow hijack potential; the unchecked NULL-array write in vlan_group_set_device() and the nr_vlan_devs underflow further corrupt kernel state.\nA:H - The primary reported outcome is `kernel BUG at net/8021q/vlan.c:99` (invalid opcode oops) or a NULL-pointer dereference, with the faulting task dying while holding RTNL and thereby wedging all subsequent network configuration; the variant also leaks vlan_info and netdev references, causing a permanent \"waiting for to become free\" unregister hang." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/8021q/vlan.c", "net/8021q/vlan.h" ], "versions": [ { "version": "ad1afb00393915a51c21b1ae8704562bf036855f", "lessThan": "ba48d3993af23753e1f1f01c8d592de9c7785f24", "status": "affected", "versionType": "git" }, { "version": "ad1afb00393915a51c21b1ae8704562bf036855f", "lessThan": "35142b3816832889e50164d993018ea5810955ae", "status": "affected", "versionType": "git" }, { "version": "ad1afb00393915a51c21b1ae8704562bf036855f", "lessThan": "047b61a24d7c866c502aeeea482892969a68f216", "status": "affected", "versionType": "git" }, { "version": "ad1afb00393915a51c21b1ae8704562bf036855f", "lessThan": "d43ef15bf4856c8c4c6c3572922331a5f06deb77", "status": "affected", "versionType": "git" }, { "version": "ad1afb00393915a51c21b1ae8704562bf036855f", "lessThan": "bb515c41306454937464da055609b5fb0a27821b", "status": "affected", "versionType": "git" }, { "version": "ad1afb00393915a51c21b1ae8704562bf036855f", "lessThan": "8984bcbd1edf5bee5be06ad771d157333b790c33", "status": "affected", "versionType": "git" }, { "version": "ad1afb00393915a51c21b1ae8704562bf036855f", "lessThan": "93715aa2d80e6c5cea1bb486321fc4585076928b", "status": "affected", "versionType": "git" }, { "version": "ad1afb00393915a51c21b1ae8704562bf036855f", "lessThan": "579d4f9ca9a9a605184a9b162355f6ba131f678d", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/8021q/vlan.c", "net/8021q/vlan.h" ], "versions": [ { "version": "2.6.36", "status": "affected" }, { "version": "0", "lessThan": "2.6.36", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.297", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.241", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.190", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.147", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.100", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.40", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.8", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "5.4.297" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "5.10.241" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "5.15.190" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.1.147" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.6.100" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.12.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.15.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.36", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ba48d3993af23753e1f1f01c8d592de9c7785f24" }, { "url": "https://git.kernel.org/stable/c/35142b3816832889e50164d993018ea5810955ae" }, { "url": "https://git.kernel.org/stable/c/047b61a24d7c866c502aeeea482892969a68f216" }, { "url": "https://git.kernel.org/stable/c/d43ef15bf4856c8c4c6c3572922331a5f06deb77" }, { "url": "https://git.kernel.org/stable/c/bb515c41306454937464da055609b5fb0a27821b" }, { "url": "https://git.kernel.org/stable/c/8984bcbd1edf5bee5be06ad771d157333b790c33" }, { "url": "https://git.kernel.org/stable/c/93715aa2d80e6c5cea1bb486321fc4585076928b" }, { "url": "https://git.kernel.org/stable/c/579d4f9ca9a9a605184a9b162355f6ba131f678d" } ], "title": "net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T17:38:35.299Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:42:08.952Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html" } ] } ] } }