CVE-2025-37921

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This is wrong and will result\nin a warning [1] being generated by the lockdep annotation that was\nadded by commit ebe642067455 (\"vxlan: Create wrappers for FDB lookup\").\n\nReproducer:\n\n # ip link add vx0 up type vxlan dstport 4789 external vnifilter local 192.0.2.1\n # bridge vni add vni 10010 remote 198.51.100.1 dev vx0\n # bridge vni del vni 10010 dev vx0\n\nFix by acquiring the hash lock before the deletion and releasing it\nafterwards. Blame the original commit that introduced the issue rather\nthan the one that exposed it.\n\n[1]\nWARNING: CPU: 3 PID: 392 at drivers/net/vxlan/vxlan_core.c:417 vxlan_find_mac+0x17f/0x1a0\n[...]\nRIP: 0010:vxlan_find_mac+0x17f/0x1a0\n[...]\nCall Trace:\n <TASK>\n __vxlan_fdb_delete+0xbe/0x560\n vxlan_vni_delete_group+0x2ba/0x940\n vxlan_vni_del.isra.0+0x15f/0x580\n vxlan_process_vni_filter+0x38b/0x7b0\n vxlan_vnifilter_process+0x3bb/0x510\n rtnetlink_rcv_msg+0x2f7/0xb70\n netlink_rcv_skb+0x131/0x360\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 __sys_sendmsg+0x121/0x1b0\n do_syscall_64+0xbb/0x1d0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53"}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The trigger is an RTM_DELTUNNEL rtnetlink message on the PF_BRIDGE family (`bridge vni del`), which requires a local socket; the racing FDB writes come from the packet path but the vulnerable unlocked deletion itself is only reachable locally.\nAC:L - The attacker owns both sides of the race \u2014 looping `bridge vni add/del` on one CPU while feeding VXLAN frames with chosen inner source MACs (spraying all 256 buckets) to drive `vxlan_snoop()` inserts into the same bucket \u2014 and it can be retried indefinitely; the lockdep WARN itself reproduces deterministically in three commands.\nPR:L - Only CAP_NET_ADMIN in the netns's user namespace is needed, checked via `netlink_net_capable()`, so an unprivileged user gets it with `unshare -Urn` and can create the vxlan vnifilter device and delete VNIs entirely within their own namespace.\nUI:N - The attacker performs every step \u2014 device creation, VNI add/delete, and packet injection \u2014 with no action by any other user or administrator.\nS:U - The corruption stays within the kernel's own security authority; this is standard in-kernel memory corruption / privilege escalation with no VM, IOMMU, or hypervisor boundary crossed.\nC:H - The lost-update on the hash bucket leaves a `call_rcu`-freed `vxlan_fdb` linked in the table, so subsequent lookups read freed memory and `vxlan_fdb_notify()` copies that reclaimed object's contents out to netlink listeners, yielding attacker-observable kernel heap disclosure.\nI:H - The use-after-free is writable \u2014 `vxlan_snoop()` stores jiffies into `f->updated` and a 16-byte peer-controlled `union vxlan_addr` into `rdst->remote_ip` inside the reclaimed object, and corrupted `pprev` pointers produce stray writes into reallocated slab memory, giving a heap-spray-based write primitive.\nA:H - The immediate observed effect is a kernel WARNING from `lockdep_assert_held_once()` (fatal under panic_on_warn), and the underlying list corruption and use-after-free reliably lead to oopses and panics on the VXLAN datapath."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/vxlan/vxlan_vnifilter.c"], "versions": [{"version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "2d4a121296aa3940d2df9906f955c2b6b4e38bc3", "status": "affected", "versionType": "git"}, {"version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "3576e9a80b6c4381b01ce0cbaa07f5e92d4492ed", "status": "affected", "versionType": "git"}, {"version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "5cb9e07f84e527974b12e82e2549fa6c0cc6eef0", "status": "affected", "versionType": "git"}, {"version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "470206205588559e60035fceb5f256640cb45f99", "status": "affected", "versionType": "git"}, {"version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "087a9eb9e5978e3ba362e1163691e41097e8ca20", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/vxlan/vxlan_vnifilter.c"], "versions": [{"version": "5.18", "status": "affected"}, {"version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.138", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.90", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.28", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.14.6", "lessThanOrEqual": "6.14.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.15", "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": "5.18", "versionEndExcluding": "6.1.138"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.6.90"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.12.28"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.14.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.15"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2d4a121296aa3940d2df9906f955c2b6b4e38bc3"}, {"url": "https://git.kernel.org/stable/c/3576e9a80b6c4381b01ce0cbaa07f5e92d4492ed"}, {"url": "https://git.kernel.org/stable/c/5cb9e07f84e527974b12e82e2549fa6c0cc6eef0"}, {"url": "https://git.kernel.org/stable/c/470206205588559e60035fceb5f256640cb45f99"}, {"url": "https://git.kernel.org/stable/c/087a9eb9e5978e3ba362e1163691e41097e8ca20"}], "title": "vxlan: vnifilter: Fix unlocked deletion of default FDB entry", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"title": "CVE Program Container", "references": [{"url": "https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html"}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:57:20.614Z"}}, {"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2025-37921", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-15T21:46:08.750355Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-15T21:52:03.984Z"}}]}}

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the racing FDB writes come from the packet path but the vulnerable unlocked deletion itself is only reachable locally.\nAC:L - The attacker owns both sides of the race \u2014 looping `bridge vni add/del` on one CPU while feeding VXLAN frames with chosen inner source MACs (spraying all 256 buckets) to drive `vxlan_snoop()` inserts into the same bucket \u2014 and it can be retried indefinitely; the lockdep WARN itself reproduces deterministically in three commands.\nPR:L - Only CAP_NET_ADMIN in the netns's user namespace is needed, checked via `netlink_net_capable()`, so an unprivileged user gets it with `unshare -Urn` and can create the vxlan vnifilter device and delete VNIs entirely within their own namespace.\nUI:N - The attacker performs every step \u2014 device creation, VNI add/delete, and packet injection \u2014 with no action by any other user or administrator.\nS:U - The corruption stays within the kernel's own security authority; this is standard in-kernel memory corruption / privilege escalation with no VM, IOMMU, or hypervisor boundary crossed.\nC:H - The lost-update on the hash bucket leaves a `call_rcu`-freed `vxlan_fdb` linked in the table, so subsequent lookups read freed memory and `vxlan_fdb_notify()` copies that reclaimed object's contents out to netlink listeners, yielding attacker-observable kernel heap disclosure.\nI:H - The use-after-free is writable \u2014 `vxlan_snoop()` stores jiffies into `f->updated` and a 16-byte peer-controlled `union vxlan_addr` into `rdst->remote_ip` inside the reclaimed object, and corrupted `pprev` pointers produce stray writes into reallocated slab memory, giving a heap-spray-based write primitive.\nA:H - The immediate observed effect is a kernel WARNING from `lockdep_assert_held_once()` (fatal under panic_on_warn), and the underlying list corruption and use-after-free reliably lead to oopses and panics on the VXLAN datapath."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "2d4a121296aa3940d2df9906f955c2b6b4e38bc3", "versionType": "git"}, {"status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "3576e9a80b6c4381b01ce0cbaa07f5e92d4492ed", "versionType": "git"}, {"status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "5cb9e07f84e527974b12e82e2549fa6c0cc6eef0", "versionType": "git"}, {"status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "470206205588559e60035fceb5f256640cb45f99", "versionType": "git"}, {"status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "lessThan": "087a9eb9e5978e3ba362e1163691e41097e8ca20", "versionType": "git"}], "programFiles": ["drivers/net/vxlan/vxlan_vnifilter.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.18"}, {"status": "unaffected", "version": "0", "lessThan": "5.18", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.138", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.90", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.28", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.14.6", "versionType": "semver", "lessThanOrEqual": "6.14.*"}, {"status": "unaffected", "version": "6.15", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/net/vxlan/vxlan_vnifilter.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/2d4a121296aa3940d2df9906f955c2b6b4e38bc3"}, {"url": "https://git.kernel.org/stable/c/3576e9a80b6c4381b01ce0cbaa07f5e92d4492ed"}, {"url": "https://git.kernel.org/stable/c/5cb9e07f84e527974b12e82e2549fa6c0cc6eef0"}, {"url": "https://git.kernel.org/stable/c/470206205588559e60035fceb5f256640cb45f99"}, {"url": "https://git.kernel.org/stable/c/087a9eb9e5978e3ba362e1163691e41097e8ca20"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: vnifilter: Fix unlocked deletion of default FDB entry\n\nWhen a VNI is deleted from a VXLAN device in 'vnifilter' mode, the FDB\nentry associated with the default remote (assuming one was configured)\nis deleted without holding the hash lock. This is wrong and will result\nin a warning [1] being generated by the lockdep annotation that was\nadded by commit ebe642067455 (\"vxlan: Create wrappers for FDB lookup\").\n\nReproducer:\n\n # ip link add vx0 up type vxlan dstport 4789 external vnifilter local 192.0.2.1\n # bridge vni add vni 10010 remote 198.51.100.1 dev vx0\n # bridge vni del vni 10010 dev vx0\n\nFix by acquiring the hash lock before the deletion and releasing it\nafterwards. Blame the original commit that introduced the issue rather\nthan the one that exposed it.\n\n[1]\nWARNING: CPU: 3 PID: 392 at drivers/net/vxlan/vxlan_core.c:417 vxlan_find_mac+0x17f/0x1a0\n[...]\nRIP: 0010:vxlan_find_mac+0x17f/0x1a0\n[...]\nCall Trace:\n <TASK>\n __vxlan_fdb_delete+0xbe/0x560\n vxlan_vni_delete_group+0x2ba/0x940\n vxlan_vni_del.isra.0+0x15f/0x580\n vxlan_process_vni_filter+0x38b/0x7b0\n vxlan_vnifilter_process+0x3bb/0x510\n rtnetlink_rcv_msg+0x2f7/0xb70\n netlink_rcv_skb+0x131/0x360\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 __sys_sendmsg+0x121/0x1b0\n do_syscall_64+0xbb/0x1d0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53"}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.138", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.90", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.28", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.14.6", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.15", "versionStartIncluding": "5.18"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:58:22.938Z"}}}, "cveMetadata": {"cveId": "CVE-2025-37921", "state": "PUBLISHED", "dateUpdated": "2026-10-15T21:52:03.984Z", "dateReserved": "2025-04-16T04:51:23.968Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2025-05-20T15:21:50.410Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/net/vxlan/vxlan_vnifilter.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2d4a121296aa3940d2df9906f955c2b6b4e38bc3", "status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "versionType": "git"}, {"lessThan": "3576e9a80b6c4381b01ce0cbaa07f5e92d4492ed", "status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "versionType": "git"}, {"lessThan": "5cb9e07f84e527974b12e82e2549fa6c0cc6eef0", "status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "versionType": "git"}, {"lessThan": "470206205588559e60035fceb5f256640cb45f99", "status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "versionType": "git"}, {"lessThan": "087a9eb9e5978e3ba362e1163691e41097e8ca20", "status": "affected", "version": "f9c4bb0b245cee35ef66f75bf409c9573d934cf9", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/net/vxlan/vxlan_vnifilter.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.18"}, {"lessThan": "5.18", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.138", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.90", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.28", "versionType": "semver"}, {"lessThanOrEqual": "6.14.*", "status": "unaffected", "version": "6.14.6", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "6.15", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "945A1B5D-9E16-488D-96CC-27B5994A3A7F", "versionEndExcluding": "6.1.138", "versionStartIncluding": "5.18", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "2BE1DB09-2D62-4C63-AF19-947300669741", "versionEndExcluding": "6.6.90", "versionStartIncluding": "6.2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "5082CE19-0F3D-4521-AB3E-810D8255F500", "versionEndExcluding": "6.12.28", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "19E5095E-5950-43EA-8E78-FC860855293F", "versionEndExcluding": "6.14.6", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*", "matchCriteriaId": "8D465631-2980-487A-8E65-40AE2B9F8ED1", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*", "matchCriteriaId": "4C9D071F-B28E-46EC-AC61-22B913390211", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*", "matchCriteriaId": "13FC0DDE-E513-465E-9E81-515702D49B74", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:*", "matchCriteriaId": "8C7B5B0E-4EEB-48F5-B4CF-0935A7633845", "vulnerable": true}], "negate": false, "operator": "OR"}]}, {"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*", "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: vnifilter: Fix unlocked deletion of default FDB entry\n\nWhen a VNI is deleted from a VXLAN device in 'vnifilter' mode, the FDB\nentry associated with the default remote (assuming one was configured)\nis deleted without holding the hash lock. This is wrong and will result\nin a warning [1] being generated by the lockdep annotation that was\nadded by commit ebe642067455 (\"vxlan: Create wrappers for FDB lookup\").\n\nReproducer:\n\n # ip link add vx0 up type vxlan dstport 4789 external vnifilter local 192.0.2.1\n # bridge vni add vni 10010 remote 198.51.100.1 dev vx0\n # bridge vni del vni 10010 dev vx0\n\nFix by acquiring the hash lock before the deletion and releasing it\nafterwards. Blame the original commit that introduced the issue rather\nthan the one that exposed it.\n\n[1]\nWARNING: CPU: 3 PID: 392 at drivers/net/vxlan/vxlan_core.c:417 vxlan_find_mac+0x17f/0x1a0\n[...]\nRIP: 0010:vxlan_find_mac+0x17f/0x1a0\n[...]\nCall Trace:\n <TASK>\n __vxlan_fdb_delete+0xbe/0x560\n vxlan_vni_delete_group+0x2ba/0x940\n vxlan_vni_del.isra.0+0x15f/0x580\n vxlan_process_vni_filter+0x38b/0x7b0\n vxlan_vnifilter_process+0x3bb/0x510\n rtnetlink_rcv_msg+0x2f7/0xb70\n netlink_rcv_skb+0x131/0x360\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 __sys_sendmsg+0x121/0x1b0\n do_syscall_64+0xbb/0x1d0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: vxlan: vnifilter: Se corrige la eliminaci\u00f3n desbloqueada de la entrada FDB predeterminada. Cuando se elimina una VNI de un dispositivo VXLAN en modo 'vnifilter', la entrada FDB asociada al control remoto predeterminado (si se configur\u00f3 uno) se elimina sin mantener el bloqueo hash. Esto es incorrecto y generar\u00e1 una advertencia [1] generada por la anotaci\u00f3n lockdep, a\u00f1adida por el commit ebe642067455 (\"vxlan: Crear envoltorios para la b\u00fasqueda FDB\"). Reproductor: # ip link add vx0 up type vxlan dstport 4789 external vnifilter local 192.0.2.1 # bridge vni add vni 10010 remote 198.51.100.1 dev vx0 # bridge vni del vni 10010 dev vx0 Se corrige adquiriendo el bloqueo hash antes de la eliminaci\u00f3n y liber\u00e1ndolo despu\u00e9s. Culpe a el commit original que introdujo el problema en lugar de a la que lo expuso. [1] ADVERTENCIA: CPU: 3 PID: 392 en drivers/net/vxlan/vxlan_core.c:417 vxlan_find_mac+0x17f/0x1a0 [...] RIP: 0010:vxlan_find_mac+0x17f/0x1a0 [...] Rastreo de llamadas: __vxlan_fdb_delete+0xbe/0x560 vxlan_vni_delete_group+0x2ba/0x940 vxlan_vni_del.isra.0+0x15f/0x580 vxlan_process_vni_filter+0x38b/0x7b0 vxlan_vnifilter_process+0x3bb/0x510 rtnetlink_rcv_msg+0x2f7/0xb70 netlink_rcv_skb+0x131/0x360 netlink_unicast+0x426/0x710 netlink_sendmsg+0x75a/0xc20 __sock_sendmsg+0xc1/0x150 ____sys_sendmsg+0x5aa/0x7b0 ___sys_sendmsg+0xfc/0x180 __sys_sendmsg+0x121/0x1b0 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 "}], "id": "CVE-2025-37921", "lastModified": "2026-10-15T22:18:21.560", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-37921", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-15T21:46:08.750355Z", "version": "2.0.3"}}]}, "published": "2025-05-20T16:15:28.713", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/087a9eb9e5978e3ba362e1163691e41097e8ca20"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2d4a121296aa3940d2df9906f955c2b6b4e38bc3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/3576e9a80b6c4381b01ce0cbaa07f5e92d4492ed"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/470206205588559e60035fceb5f256640cb45f99"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/5cb9e07f84e527974b12e82e2549fa6c0cc6eef0"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"], "url": "https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: vxlan: vnifilter: Fix unlocked deletion of default FDB entry", "id": "2367546", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2367546"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.1", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nvxlan: vnifilter: Fix unlocked deletion of default FDB entry\nWhen a VNI is deleted from a VXLAN device in 'vnifilter' mode, the FDB\nentry associated with the default remote (assuming one was configured)\nis deleted without holding the hash lock. This is wrong and will result\nin a warning [1] being generated by the lockdep annotation that was\nadded by commit ebe642067455 (\"vxlan: Create wrappers for FDB lookup\").\nReproducer:\n# ip link add vx0 up type vxlan dstport 4789 external vnifilter local 192.0.2.1\n# bridge vni add vni 10010 remote 198.51.100.1 dev vx0\n# bridge vni del vni 10010 dev vx0\nFix by acquiring the hash lock before the deletion and releasing it\nafterwards. Blame the original commit that introduced the issue rather\nthan the one that exposed it.\n[1]\nWARNING: CPU: 3 PID: 392 at drivers/net/vxlan/vxlan_core.c:417 vxlan_find_mac+0x17f/0x1a0\n[...]\nRIP: 0010:vxlan_find_mac+0x17f/0x1a0\n[...]\nCall Trace:\n<TASK>\n__vxlan_fdb_delete+0xbe/0x560\nvxlan_vni_delete_group+0x2ba/0x940\nvxlan_vni_del.isra.0+0x15f/0x580\nvxlan_process_vni_filter+0x38b/0x7b0\nvxlan_vnifilter_process+0x3bb/0x510\nrtnetlink_rcv_msg+0x2f7/0xb70\nnetlink_rcv_skb+0x131/0x360\nnetlink_unicast+0x426/0x710\nnetlink_sendmsg+0x75a/0xc20\n__sock_sendmsg+0xc1/0x150\n____sys_sendmsg+0x5aa/0x7b0\n___sys_sendmsg+0xfc/0x180\n__sys_sendmsg+0x121/0x1b0\ndo_syscall_64+0xbb/0x1d0\nentry_SYSCALL_64_after_hwframe+0x4b/0x53"], "name": "CVE-2025-37921", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-05-20T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-37921\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-37921\nhttps://lore.kernel.org/linux-cve-announce/2025052002-CVE-2025-37921-bee5@gregkh/T"], "statement": "VXLAN vnifilter bug causing unprotected FDB deletion. Triggers kernel WARN and may lead to instability. No exploitability or privilege escalation, but relevant for robustness in advanced VXLAN setups.", "threat_severity": "Moderate"}

{"created": "2025-06-27T09:26:51.210890+00:00", "updated": "2025-06-27T09:26:51.210945+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}