NULL Pointer Dereference Affecting kernel-rt package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applicationsSnyk Learn
Learn about NULL Pointer Dereference vulnerabilities in an interactive lesson.
Start learning- Snyk IDSNYK-RHEL9-KERNELRT-6629203
- published18 Apr 2024
- disclosed17 Apr 2024
Introduced: 17 Apr 2024
CVE-2024-26903 (opens in a new tab)How to fix?
There is no fixed version for RHEL:9 kernel-rt.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-rt package and not the kernel-rt package as distributed by RHEL.
See How to fix? for RHEL:9 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:
In the packets captured during a normal connection, the host sends a
Read Encryption Key Sizetype ofHCI_CMDpacket (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.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.
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)->chan->conn;had already been released, and when the function executedreturn hci_conn_security(conn->hcon, d->sec_level, auth_type, d->out);, specifically when accessingconn->hcon, a null-ptr-deref error occurred.
To fix this bug, check if sk->sk_state is BT_CLOSED before calling
rfcomm_recv_frame in rfcomm_process_rx.
References
- https://access.redhat.com/security/cve/CVE-2024-26903
- https://git.kernel.org/stable/c/2535b848fa0f42ddff3e5255cf5e742c9b77bb26
- https://git.kernel.org/stable/c/369f419c097e82407dd429a202cde9a73d3ae29b
- https://git.kernel.org/stable/c/3ead59bafad05f2967ae2438c0528d53244cfde5
- https://git.kernel.org/stable/c/567c0411dc3b424fc7bd1e6109726d7ba32d4f73
- https://git.kernel.org/stable/c/5f369efd9d963c1f711a06c9b8baf9f5ce616d85
- https://git.kernel.org/stable/c/5f9fe302dd3a9bbc50f4888464c1773f45166bfd
- https://git.kernel.org/stable/c/81d7d920a22fd58ef9aedb1bd0a68ee32bd23e96
- https://git.kernel.org/stable/c/8d1753973f598531baaa2c1033cf7f7b5bb004b0
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
- https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html