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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2024-26903
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2024-04-17 11:15:11 UTC
Updated2026-05-12 12:16:25 UTC
DescriptionIn 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)->chan->conn;` had already been released, and when the function executed `return hci_conn_security(conn->hcon, d->sec_level, auth_type, d->out);`, specifically when accessing `conn->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.

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-476 | CWE-476 CWE-476 NULL Pointer Dereference

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary5.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.1ADPDECLARED5.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary5.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 369f419c097e82407dd429a202cde9a73d3ae29b git Not specified
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 5f369efd9d963c1f711a06c9b8baf9f5ce616d85 git Not specified
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 81d7d920a22fd58ef9aedb1bd0a68ee32bd23e96 git Not specified
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 8d1753973f598531baaa2c1033cf7f7b5bb004b0 git Not specified
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 567c0411dc3b424fc7bd1e6109726d7ba32d4f73 git Not specified
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 3ead59bafad05f2967ae2438c0528d53244cfde5 git Not specified
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 5f9fe302dd3a9bbc50f4888464c1773f45166bfd git Not specified
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 2535b848fa0f42ddff3e5255cf5e742c9b77bb26 git Not specified
CNA Linux Linux affected 2.6.12 Not specified
CNA Linux Linux unaffected 2.6.12 semver Not specified
CNA Linux Linux unaffected 4.19.311 4.19.* semver Not specified
CNA Linux Linux unaffected 5.4.273 5.4.* semver Not specified
CNA Linux Linux unaffected 5.10.214 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.153 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.83 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.23 6.6.* semver Not specified
CNA Linux Linux unaffected 6.7.11 6.7.* semver Not specified
CNA Linux Linux unaffected 6.8 * original_commit_for_fix Not specified
ADP Siemens SIMATIC S7-1500 TM MFP - GNU/Linux Subsystem affected * custom Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/81d7d920a22fd58ef9aedb1bd0a68ee32bd23e96 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
lists.debian.org/debian-lts-announce/2024/06/msg00017.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org
git.kernel.org/stable/c/8d1753973f598531baaa2c1033cf7f7b5bb004b0 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/5f369efd9d963c1f711a06c9b8baf9f5ce616d85 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
cert-portal.siemens.com/productcert/html/ssa-265688.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e cert-portal.siemens.com
git.kernel.org/stable/c/5f9fe302dd3a9bbc50f4888464c1773f45166bfd af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/3ead59bafad05f2967ae2438c0528d53244cfde5 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/567c0411dc3b424fc7bd1e6109726d7ba32d4f73 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
lists.debian.org/debian-lts-announce/2024/06/msg00020.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org
git.kernel.org/stable/c/369f419c097e82407dd429a202cde9a73d3ae29b af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
git.kernel.org/stable/c/2535b848fa0f42ddff3e5255cf5e742c9b77bb26 af854a3a-2127-422b-91ae-364da2661108 git.kernel.org Patch
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