CVE-2024-50255 Bluetooth: hci: fix null-ptr-deref in hci_read_supported_codecs

What is CVE-2024-50255?

CVE-2024-50255 is a medium-severity vulnerability in Linux kernel, published on 9 Nov 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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: ffff88810b9ac000 FS: 0000000000000000(0000) GS:ffff8881f6c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6ddaa3439e CR3: 0000000139764003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> hci_read_local_codecs_sync net/bluetooth/hci_sync.c:4546 [inline] hci_init_stage_sync net/bluetooth/hci_sync.c:3441 [inline] hci_init4_sync net/bluetooth/hci_sync.c:4706 [inline] hci_init_sync net/bluetooth/hci_sync.c:4742 [inline] hci_dev_init_sync net/bluetooth/hci_sync.c:4912 [inline] hci_dev_open_sync+0x19a9/0x2d30 net/bluetooth/hci_sync.c:4994 hci_dev_do_open net/bluetooth/hci_core.c:483 [inline] hci_power_on+0x11e/0x560 net/bluetooth/hci_core.c:1015 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0x8ef/0x14f0 kernel/workqueue.c:3348 worker_thread+0x91f/0xe50 kernel/workqueue.c:3429 kthread+0x2cb/0x360 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Weakness: CWE-476

Which versions are affected by CVE-2024-50255?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-50255?

Apply the vendor's patch.

Is CVE-2024-50255 being exploited?

There is no known exploitation of CVE-2024-50255 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-53298, BELL-CVE-2024-50255, DEBIAN-CVE-2024-50255, GHSA-5hxv-rgfg-978g, UBUNTU-CVE-2024-50255.