GHSA-X58J-HW5G-JQCQ
Vulnerability from github – Published: 2025-05-20 18:30 – Updated: 2025-11-10 21:30In the Linux kernel, the following vulnerability has been resolved:
vxlan: vnifilter: Fix unlocked deletion of default FDB entry
When a VNI is deleted from a VXLAN device in 'vnifilter' mode, the FDB entry associated with the default remote (assuming one was configured) is deleted without holding the hash lock. This is wrong and will result in a warning [1] being generated by the lockdep annotation that was added by commit ebe642067455 ("vxlan: Create wrappers for FDB lookup").
Reproducer:
# 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
Fix by acquiring the hash lock before the deletion and releasing it afterwards. Blame the original commit that introduced the issue rather than the one that exposed it.
[1] WARNING: CPU: 3 PID: 392 at drivers/net/vxlan/vxlan_core.c:417 vxlan_find_mac+0x17f/0x1a0 [...] RIP: 0010:vxlan_find_mac+0x17f/0x1a0 [...] Call Trace: __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
{
"affected": [],
"aliases": [
"CVE-2025-37921"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-05-20T16:15:28Z",
"severity": "HIGH"
},
"details": "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 \u0027vnifilter\u0027 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 \u003cTASK\u003e\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",
"id": "GHSA-x58j-hw5g-jqcq",
"modified": "2025-11-10T21:30:29Z",
"published": "2025-05-20T18:30:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-37921"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/087a9eb9e5978e3ba362e1163691e41097e8ca20"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2d4a121296aa3940d2df9906f955c2b6b4e38bc3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3576e9a80b6c4381b01ce0cbaa07f5e92d4492ed"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/470206205588559e60035fceb5f256640cb45f99"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5cb9e07f84e527974b12e82e2549fa6c0cc6eef0"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.