CVE-2024-50255

Description

From CVE.org

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

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score5.55.5N/A
Attack VectorLocalLocalN/A
Attack ComplexityLowLowN/A
Privileges RequiredLowLowN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityNoneNoneN/A
Integrity ImpactNoneNoneN/A
Availability ImpactHighHighN/A

Vector

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

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

Understanding the Weakness (CWE)

CWE-476

Availability

Technical Impact: DoS: Crash, Exit, or Restart

NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.

Integrity,Confidentiality

Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory

In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.

Frequently Asked Questions

Not sure what something means? Check out our Security Glossary.

Want to get errata notifications? Sign up here.