CVE-2026-74677
- Source
- https://cve.org/CVERecord?id=CVE-2026-74677
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74677.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-74677
- Downstream
- Published
- 2026-08-22T15:32:46Z
- Modified
- 2026-10-08T02:48:52Z
- Summary
- net: usb: ipheth: fix carrier_work UAF on disconnect
- Details
-
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).
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74677.json" }- References
-
- https://git.kernel.org/stable/c/2c7496124e94c7f9c3daa5c5b1fb563ca9d62c45
- https://git.kernel.org/stable/c/48303f3ae0fa6e102f3fc7dbf1688cc179131962
- https://git.kernel.org/stable/c/d07133fe1befae9a1e4c4c5e46ef0b73d2992020
- https://git.kernel.org/stable/c/fde39b8a521780391fb4e5bda2c0aa4928947f12
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74677.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-74677
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedbb1b40c7cb863f0800a6410c7dcb86cf3f28d3b1Fixedd07133fe1befae9a1e4c4c5e46ef0b73d2992020Fixed2c7496124e94c7f9c3daa5c5b1fb563ca9d62c45Fixed48303f3ae0fa6e102f3fc7dbf1688cc179131962Fixedfde39b8a521780391fb4e5bda2c0aa4928947f12
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced4.4.180Fixed4.5
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced4.9.173Fixed4.10
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced4.14.116Fixed4.15
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced4f2df9fd07698bece3321fbf9e4b6dbcb9babccc
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedea7d6be58c2e6c1f426b48994bb22b2393c90963
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedf5bca75dc46701f4c0d1dcbaae401233ae7ff06b