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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2026-64539

Bluetooth: eir: Fix stack OOB write when prepending the Flags AD

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: eir: Fix stack OOB write when prepending the Flags AD eir_create_adv_data() builds the advertising data into a fixed-size buffer ("size", 31 for the legacy path). It may prepend a 3-byte "Flags" AD structure (LE_AD_NO_BREDR on an LE-only controller) and then copies the per-instance data without checking that it still fits: memcpy(ptr, adv->adv_data, adv->adv_data_len); tlv_data_max_len() only reserves those 3 bytes when the user-supplied flags carry a managed-flags bit, so an instance added with flags == 0 is accepted with adv_data_len up to the full buffer. At advertise time the flags are still prepended, and the memcpy() writes 3 + adv_data_len bytes into the size-byte buffer: BUG: KASAN: stack-out-of-bounds in eir_create_adv_data (net/bluetooth/eir.c:301) Write of size 31 at addr ffff88800a547bdc by task kworker/u9:0/65 Workqueue: hci0 hci_cmd_sync_work __asan_memcpy (mm/kasan/shadow.c:106) eir_create_adv_data (net/bluetooth/eir.c:301) hci_update_adv_data_sync (net/bluetooth/hci_sync.c:1310) hci_schedule_adv_instance_sync (net/bluetooth/hci_sync.c:1817) hci_cmd_sync_work (net/bluetooth/hci_sync.c:332) This frame has 1 object: [32, 64) 'cp' The "Flags" structure is added by the kernel, not requested by userspace, so only prepend it when it fits together with the instance advertising data; when there is no room for both, drop the flags rather than the user-provided data. Reachable by a local user with CAP_NET_ADMIN owning an LE-only controller on the legacy advertising path.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • b44133ff03be30b55f23036e62f403a3f7784fce to < 0f0b6232af56441d0a2dcb173cc4f8d8aab39014affected
  • b44133ff03be30b55f23036e62f403a3f7784fce to < 9174992ee1045c9c96e53eecda64f49dd7e8fbbaaffected
  • b44133ff03be30b55f23036e62f403a3f7784fce to < 09301f1fdf2aef8cce34d0c4650c30e7edb1ced9affected
  • b44133ff03be30b55f23036e62f403a3f7784fce to < f1b4df9c260c51726da2e86e19322825fddeefd0affected
  • b44133ff03be30b55f23036e62f403a3f7784fce to < 57077eeb586c42f124bc09e018449362223067b3affected
  • b44133ff03be30b55f23036e62f403a3f7784fce to < 6f5fb689fdf80bdd143f22a502f9eb1f3c85e286affected

Linux Linux

Default version status: affected

  • 4.1affected
  • 0 to < 4.1unaffected
  • 6.1.178 to ≤ 6.1.*unaffected
  • 6.6.160 to ≤ 6.6.*unaffected
  • 6.12.97 to ≤ 6.12.*unaffected
  • 6.18.40 to ≤ 6.18.*unaffected
  • 7.1.5 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References