Affected: Linux

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

Bluetooth: hci: fix null-ptr-deref in hci_read_supported_codecs

Fix __hci_cmd_sync_sk() to return not NULL for unknown opcodes.

__hci_cmd_sync_sk() returns NULL if a command returns a status event. However, it also returns NULL where an opcode doesn't exist in the hci_cc table because hci_cmd_complete_evt() assumes status = skb->data[0] for unknown opcodes. This leads to null-ptr-deref in cmd_sync for HCI_OP_READ_LOCAL_CODECS as there is no hci_cc for HCI_OP_READ_LOCAL_CODECS, which always assumes status = skb->data[0].

KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077] CPU: 1 PID: 2000 Comm: kworker/u9:5 Not tainted 6.9.0-ga6bcb805883c-dirty #10 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: hci7 hci_power_on RIP: 0010:hci_read_supported_codecs+0xb9/0x870 net/bluetooth/hci_codec.c:138 Code: 08 48 89 ef e8 b8 c1 8f fd 48 8b 75 00 e9 96 00 00 00 49 89 c6 48 ba 00 00 00 00 00 fc ff df 4c 8d 60 70 4c 89 e3 48 c1 eb 03 <0f> b6 04 13 84 c0 0f 85 82 06 00 00 41 83 3c 24 02 77 0a e8 bf 78 RSP: 0018:ffff888120bafac8 EFLAGS: 00010212 RAX: 0000000000000000 RBX: 000000000000000e RCX: ffff8881173f0040 RDX: dffffc0000000000 RSI: ffffffffa58496c0 RDI: ffff88810b9ad1e4 RBP: ffff88810b9ac000 R08: ffffffffa77882a7 R09: 1ffffffff4ef1054 R10: dffffc0000000000 R11: fffffbfff4ef1055 R12: 0000000000000070 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88810…