CVE-2025-39908

In the Linux kernel, the following vulnerability has been resolved:

net: dev_ioctl: take ops lock in hwtstamp lower paths

ndo hwtstamp callbacks are expected to run under the per-device ops lock. Make the lower get/set paths consistent with the rest of ndo invocations.

Kernel log: WARNING: CPU: 13 PID: 51364 at ./include/net/netdev_lock.h:70 __netdev_update_features+0x4bd/0xe60 ... RIP: 0010:__netdev_update_features+0x4bd/0xe60 ... Call Trace: <TASK> netdev_update_features+0x1f/0x60 mlx5_hwtstamp_set+0x181/0x290 [mlx5_core] mlx5e_hwtstamp_set+0x19/0x30 [mlx5_core] dev_set_hwtstamp_phylib+0x9f/0x220 dev_set_hwtstamp_phylib+0x9f/0x220 dev_set_hwtstamp+0x13d/0x240 dev_ioctl+0x12f/0x4b0 sock_ioctl+0x171/0x370 __x64_sys_ioctl+0x3f7/0x900 ? __sys_setsockopt+0x69/0xb0 do_syscall_64+0x6f/0x2e0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ... </TASK> .... ---[ end trace 0000000000000000 ]---

Note that the mlx5_hwtstamp_set and mlx5e_hwtstamp_set functions shown in the trace come from an in progress patch converting the legacy ioctl to ndo_hwtstamp_get/set and are not present in mainline.

This vulnerability does not affect supported Red Hat Enterprise Linux releases as the vulnerable network device control logic is not present in shipped kernels. The underlying flaw involves improper locking during hardware timestamping ioctl operations, which could lead to kernel warnings or race conditions when reconfiguring device features. Because Red Hat kernels predate the introduction of this upstream code change, no risk is posed to Red Hat customer deployments.