NULL Pointer Dereference Affecting kernel-uek-doc package, versions <0:4.1.12-124.89.4.el6uek


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.04% (5th percentile)

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  • Snyk IDSNYK-ORACLE6-KERNELUEKDOC-7886774
  • published4 Sept 2024
  • disclosed17 Apr 2024

Introduced: 17 Apr 2024

CVE-2024-26903  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade Oracle:6 kernel-uek-doc to version 0:4.1.12-124.89.4.el6uek or higher.
This issue was patched in ELSA-2024-12606.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-uek-doc package and not the kernel-uek-doc package as distributed by Oracle. See How to fix? for Oracle:6 relevant fixed versions and status.

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

Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security

During our fuzz testing of the connection and disconnection process at the RFCOMM layer, we discovered this bug. By comparing the packets from a normal connection and disconnection process with the testcase that triggered a KASAN report. We analyzed the cause of this bug as follows:

  1. In the packets captured during a normal connection, the host sends a Read Encryption Key Size type of HCI_CMD packet (Command Opcode: 0x1408) to the controller to inquire the length of encryption key.After receiving this packet, the controller immediately replies with a Command Completepacket (Event Code: 0x0e) to return the Encryption Key Size.

  2. In our fuzz test case, the timing of the controller's response to this packet was delayed to an unexpected point: after the RFCOMM and L2CAP layers had disconnected but before the HCI layer had disconnected.

  3. After receiving the Encryption Key Size Response at the time described in point 2, the host still called the rfcomm_check_security function. However, by this time struct l2cap_conn *conn = l2cap_pi(sk)-&gt;chan-&gt;conn; had already been released, and when the function executed return hci_conn_security(conn-&gt;hcon, d-&gt;sec_level, auth_type, d-&gt;out);, specifically when accessing conn-&gt;hcon, a null-ptr-deref error occurred.

To fix this bug, check if sk-&gt;sk_state is BT_CLOSED before calling rfcomm_recv_frame in rfcomm_process_rx.

CVSS Scores

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