CVE-2025-21701net: avoid race between device unregistration and ethnl ops
- 7.8HighCVSS base score
- 0.17%Exploitation in 30 daysEPSS · top 93% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: net: avoid race between device unregistration and ethnl ops The following trace can be seen if a device is being unregistered while its number of channels are being modified. DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: CPU: 3 PID: 3754 at kernel/locking/mutex.c:564 __mutex_lock+0xc8a/0x1120 CPU: 3 UID: 0 PID: 3754 Comm: ethtool Not tainted 6.13.0-rc6+ #771 RIP: 0010:__mutex_lock+0xc8a/0x1120 Call Trace: <TASK> ethtool_check_max_channel+0x1ea/0x880 ethnl_set_channels+0x3c3/0xb10 ethnl_default_set_doit+0x306/0x650 genl_family_rcv_msg_doit+0x1e3/0x2c0 genl_rcv_msg+0x432/0x6f0 netlink_rcv_skb+0x13d/0x3b0 genl_rcv+0x28/0x40 netlink_unicast+0x42e/0x720 netlink_sendmsg+0x765/0xc20 __sys_sendto+0x3ac/0x420 __x64_sys_sendto+0xe0/0x1c0 do_syscall_64+0x95/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e This is because unregister_netdevice_many_notify might run before the rtnl lock section of ethnl operations, eg. set_channels in the above example. In this example the rss lock would be destroyed by the device unregistration path before being used again, but in general running ethnl operations while dismantle has started is not a good idea. Fix this by denying any operation on devices being unregistered. A check was already there in ethnl_ops_begin, but not wide enough. Note that the same issue cannot be seen on the ioctl version (__dev_ethtool) because the device reference is retrieved from within the rtnl lock section there. Once dismantle started, the net device is unlisted and no reference will be found.
Timeline
ID reserved
By Linux
- 46 days later
· 46 days later
Published
- 20 months later
· 20 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CISA-ADPADP (enrichment) | 3.1 | High7.4 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Medium4.7 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.17% · top 93% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected cfd719f04267108f5f5bf802b9d7de69e99a99f9 – < 26bc6076798aa4dc83a07d0a386f9e57c94e8517
- affected dde91ccfa25fd58f64c397d91b81a4b393100ffa – < b1cb37a31a482df3dd35a6ac166282dac47664f4
- affected dde91ccfa25fd58f64c397d91b81a4b393100ffa – < 2f29127e94ae9fdc7497331003d6860e9551cdf3
- affected dde91ccfa25fd58f64c397d91b81a4b393100ffa – < b382ab9b885cbb665e0e70a727f101c981b4edf3
- affected dde91ccfa25fd58f64c397d91b81a4b393100ffa – < 4dc880245f9b529fa8f476b5553c799d2848b47b
- affected dde91ccfa25fd58f64c397d91b81a4b393100ffa – < 12e070eb6964b341b41677fd260af5a305316a1f
- affected 7c26da3be1e9843a15b5318f90db8a564479d2ac
- affected 5.15.8 – < 5.15.179
- affected 5.10.87 – < 5.11
- affected 5.16
- unaffected < 5.16
- unaffected 5.15.179 – ≤ 5.15.*
- unaffected 6.1.129 – ≤ 6.1.*
- unaffected 6.6.76 – ≤ 6.6.*
- unaffected 6.12.13 – ≤ 6.12.*
- unaffected 6.13.2 – ≤ 6.13.*
- unaffected 6.14 – ≤ *
References
References8
- https://git.kernel.org/stable/c/26bc6076798aa4dc83a07d0a386f9e57c94e8517 (opens in a new tab)
- https://git.kernel.org/stable/c/b1cb37a31a482df3dd35a6ac166282dac47664f4 (opens in a new tab)
- https://git.kernel.org/stable/c/2f29127e94ae9fdc7497331003d6860e9551cdf3 (opens in a new tab)
- https://git.kernel.org/stable/c/b382ab9b885cbb665e0e70a727f101c981b4edf3 (opens in a new tab)
- https://git.kernel.org/stable/c/4dc880245f9b529fa8f476b5553c799d2848b47b (opens in a new tab)
- https://git.kernel.org/stable/c/12e070eb6964b341b41677fd260af5a305316a1f (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-2650 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-21701)Record last updated .