net: usb: ipheth: fix carrier_work UAF on disconnect
Summary
| CVE | CVE-2026-74677 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-22 16:16:41 UTC |
| Updated | 2026-08-22 16:16:41 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: net: usb: ipheth: fix carrier_work UAF on disconnect ipheth_sndbulk_callback() re-arms the carrier-check work on any non-zero URB status: else schedule_delayed_work(&dev->carrier_work, 0); Nothing ties that to the interface being up, so the work can be armed again after ipheth_close() has already drained it, and stay armed until the netdev whose private area embeds it is freed. On unplug with a TX URB in flight, ipheth_disconnect() drains the work through unregister_netdev() -> ipheth_close() -> cancel_delayed_work_sync() and only then calls ipheth_kill_urbs(). usb_kill_urb() completes the in-flight TX URB with -ENOENT, so ipheth_sndbulk_callback() runs after the drain and re-arms carrier_work. The same completion also re-arms the work if the interface is only brought down while a TX URB is in flight, and ipheth_carrier_check_work() then keeps re-queueing itself once a second. unregister_netdev() does not call ipheth_close() for an already-down interface, so nothing drains it on the later unplug either. In both cases free_netdev() frees the netdev while carrier_work is still pending, and ipheth_carrier_check_work() dereferences freed memory. Tie the work to the interface state instead of chasing the completion: disable it in ipheth_close() and enable it in ipheth_open(), so a schedule_delayed_work() from the URB completion is a no-op whenever the interface is not up. disable_delayed_work_sync() also waits for a running instance, so it fully replaces the cancel_delayed_work_sync() it takes the place of. The work starts out disabled in ipheth_probe() so the enable/disable counts balance from the first open. Reproduced under KASAN on linux-next (next-20260731) with dummy_hcd and raw-gadget standing in for the device, driving the second path above (the interface is already down, so unregister_netdev() does not call ipheth_close()): 15 of 15 unpatched boots report a slab-use-after-free in __run_timers(), freed by ipheth_disconnect() and re-armed from ipheth_sndbulk_callback() via queue_delayed_work_on(). The same trigger on a kernel differing only by this patch reports 0 of 15, and the carrier check still functions across open/close cycles. The reproducer needs an attached USB device that stops draining bulk OUT, plus a link down and unplug, driven as root. It is not a privilege boundary crossing and no exploit primitive was developed. Found by 0sec (https://0sec.ai). |
Risk And Classification
EPSS: 0.001680000 probability, percentile 0.062030000 (date 2026-08-24)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected bb1b40c7cb863f0800a6410c7dcb86cf3f28d3b1 d07133fe1befae9a1e4c4c5e46ef0b73d2992020 git | Not specified |
| CNA | Linux | Linux | affected bb1b40c7cb863f0800a6410c7dcb86cf3f28d3b1 2c7496124e94c7f9c3daa5c5b1fb563ca9d62c45 git | Not specified |
| CNA | Linux | Linux | affected bb1b40c7cb863f0800a6410c7dcb86cf3f28d3b1 48303f3ae0fa6e102f3fc7dbf1688cc179131962 git | Not specified |
| CNA | Linux | Linux | affected bb1b40c7cb863f0800a6410c7dcb86cf3f28d3b1 fde39b8a521780391fb4e5bda2c0aa4928947f12 git | Not specified |
| CNA | Linux | Linux | affected 4f2df9fd07698bece3321fbf9e4b6dbcb9babccc git | Not specified |
| CNA | Linux | Linux | affected ea7d6be58c2e6c1f426b48994bb22b2393c90963 git | Not specified |
| CNA | Linux | Linux | affected f5bca75dc46701f4c0d1dcbaae401233ae7ff06b git | Not specified |
| CNA | Linux | Linux | affected 4.4.180 4.5 semver | Not specified |
| CNA | Linux | Linux | affected 4.9.173 4.10 semver | Not specified |
| CNA | Linux | Linux | affected 4.14.116 4.15 semver | Not specified |
| CNA | Linux | Linux | affected 4.15 | Not specified |
| CNA | Linux | Linux | unaffected 4.15 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.104 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.45 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.9 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/d07133fe1befae9a1e4c4c5e46ef0b73d2992020 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/fde39b8a521780391fb4e5bda2c0aa4928947f12 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/2c7496124e94c7f9c3daa5c5b1fb563ca9d62c45 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/48303f3ae0fa6e102f3fc7dbf1688cc179131962 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.