CVE-2026-64539
Gravedad:
Pendiente de análisis
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
27/07/2026
Última modificación:
27/07/2026
Descripción
*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
Bluetooth: eir: Fix stack OOB write when prepending the Flags AD<br />
<br />
eir_create_adv_data() builds the advertising data into a fixed-size<br />
buffer ("size", 31 for the legacy path). It may prepend a 3-byte "Flags"<br />
AD structure (LE_AD_NO_BREDR on an LE-only controller) and then copies<br />
the per-instance data without checking that it still fits:<br />
<br />
memcpy(ptr, adv->adv_data, adv->adv_data_len);<br />
<br />
tlv_data_max_len() only reserves those 3 bytes when the user-supplied<br />
flags carry a managed-flags bit, so an instance added with flags == 0 is<br />
accepted with adv_data_len up to the full buffer. At advertise time the<br />
flags are still prepended, and the memcpy() writes 3 + adv_data_len<br />
bytes into the size-byte buffer:<br />
<br />
BUG: KASAN: stack-out-of-bounds in eir_create_adv_data (net/bluetooth/eir.c:301)<br />
Write of size 31 at addr ffff88800a547bdc by task kworker/u9:0/65<br />
Workqueue: hci0 hci_cmd_sync_work<br />
__asan_memcpy (mm/kasan/shadow.c:106)<br />
eir_create_adv_data (net/bluetooth/eir.c:301)<br />
hci_update_adv_data_sync (net/bluetooth/hci_sync.c:1310)<br />
hci_schedule_adv_instance_sync (net/bluetooth/hci_sync.c:1817)<br />
hci_cmd_sync_work (net/bluetooth/hci_sync.c:332)<br />
This frame has 1 object:<br />
[32, 64) &#39;cp&#39;<br />
<br />
The "Flags" structure is added by the kernel, not requested by<br />
userspace, so only prepend it when it fits together with the instance<br />
advertising data; when there is no room for both, drop the flags rather<br />
than the user-provided data.<br />
<br />
Reachable by a local user with CAP_NET_ADMIN owning an LE-only<br />
controller on the legacy advertising path.
Impacto
Referencias a soluciones, herramientas e información
- https://git.kernel.org/stable/c/09301f1fdf2aef8cce34d0c4650c30e7edb1ced9
- https://git.kernel.org/stable/c/0f0b6232af56441d0a2dcb173cc4f8d8aab39014
- https://git.kernel.org/stable/c/57077eeb586c42f124bc09e018449362223067b3
- https://git.kernel.org/stable/c/6f5fb689fdf80bdd143f22a502f9eb1f3c85e286
- https://git.kernel.org/stable/c/f1b4df9c260c51726da2e86e19322825fddeefd0



