Answer in brief
CVE-2025-21701 records a High severity (CVSS 7.8) vulnerability in net: avoid race between device unregistration and ethnl ops. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=cfd719f04267108f5f5bf802b9d7de69e99a99f9 <26bc6076798aa4dc83a07d0a386f9e57c94e8517 || >=dde91ccfa25fd58f64c397d91b81a4b393100ffa <b1cb37a31a482df3dd35a6ac166282dac47664f4 || >=dde91ccfa25fd58f64c397d91b81a4b393100ffa <2f29127e94ae9fdc7497331003d6860e9551cdf3 || >=dde91ccfa25fd58f64c397d91b81a4b393100ffa <b382ab9b885cbb665e0e70a727f101c981b4edf3 || >=dde91ccfa25fd58f64c397d91b81a4b393100ffa <4dc880245f9b529fa8f476b5553c799d2848b47b || >=dde91ccfa25fd58f64c397d91b81a4b393100ffa <12e070eb6964b341b41677fd260af5a305316a1f || 7c26da3be1e9843a15b5318f90db8a564479d2ac || >=5.15.8 <5.15.179 || >=5.10.87 <5.11 | 26bc6076798aa4dc83a07d0a386f9e57c94e8517, b1cb37a31a482df3dd35a6ac166282dac47664f4, 2f29127e94ae9fdc7497331003d6860e9551cdf3, b382ab9b885cbb665e0e70a727f101c981b4edf3, 4dc880245f9b529fa8f476b5553c799d2848b47b, 12e070eb6964b341b41677fd260af5a305316a1f, 5.15.179, 5.11 |
| Linux/Linuxgeneric | 5.16 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Feb 13, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.