CVE-2022-48947

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

Bluetooth: L2CAP: Fix u8 overflow

By keep sending L2CAP_CONF_REQ packets, chan->num_conf_rsp increases multiple times and eventually it will wrap around the maximum number (i.e., 255). This patch prevents this by adding a boundary check with L2CAP_MAX_CONF_RSP

Btmon log: Bluetooth monitor ver 5.64 = Note: Linux version 6.1.0-rc2 (x86_64) 0.264594 = Note: Bluetooth subsystem version 2.22 0.264636 @ MGMT Open: btmon (privileged) version 1.22 {0x0001} 0.272191 = New Index: 00:00:00:00:00:00 (Primary,Virtual,hci0) [hci0] 13.877604 @ RAW Open: 9496 (privileged) version 2.22 {0x0002} 13.890741 = Open Index: 00:00:00:00:00:00 [hci0] 13.900426 (...)

ACL Data RX: Handle 200 flags 0x00 dlen 1033 #32 [hci0] 14.273106 invalid packet size (12 != 1033) 08 00 01 00 02 01 04 00 01 10 ff ff ............ ACL Data RX: Handle 200 flags 0x00 dlen 1547 #33 [hci0] 14.273561 invalid packet size (14 != 1547) 0a 00 01 00 04 01 06 00 40 00 00 00 00 00 ........@..... ACL Data RX: Handle 200 flags 0x00 dlen 2061 #34 [hci0] 14.274390 invalid packet size (16 != 2061) 0c 00 01 00 04 01 08 00 40 00 00 00 00 00 00 04 ........@....... ACL Data RX: Handle 200 flags 0x00 dlen 2061 #35 [hci0] 14.274932 invalid packet size (16 != 2061) 0c 00 01 00 04 01 08 00 40 00 00 00 07 00 03 00 ........@....... = bluetoothd: Bluetooth daemon 5.43 14.401828 ACL Data RX: Handle 200 flags 0x00 dlen 1033 #36 [hci0] 14.275753 invalid packet size (12 != 1033) 08 00 01 00 04 01 04 00 40 00 00 00 ........@...

This issue is fixed in RHEL-9.4 and above (including RHEL 8.10)

ceae2a8af1e2 (in rhel-9.4, rhel-9.5, rhel-9.6) Bluetooth: L2CAP: Fix u8 overflow
371b9a14a101 (in rhel-8.10) Bluetooth: L2CAP: Fix u8 overflow

Please note that while RHEL-9 kernel-rt still appears as affected, it has been fixed in the same RHSA as RHEL-9 kernel. This is because from RHEL-9.3 onwards, the kernel and kernel-rt fixes are bundled together in a single errata.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.