CVE-2024-50255

Published Nov 9, 2024

Last updated 7 months ago

Overview

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
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-476
134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-476

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: coresight: tmc-etr: Fix race condition between sysfs and perf mode When trying to run perf and sysfs mode simultaneously, the WARN_ON() in tmc_etr_enable_hw() is triggered sometimes: WARNING: CPU: 42 PID: 3911571 at drivers/hwtracing/coresight/coresight-tmc-etr.c:1060 tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] [..snip..] Call trace: tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] (P) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] (L) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] coresight_enable_path+0x1c8/0x218 [coresight] coresight_enable_sysfs+0xa4/0x228 [coresight] enable_source_store+0x58/0xa8 [coresight] dev_attr_store+0x20/0x40 sysfs_kf_write+0x4c/0x68 kernfs_fop_write_iter+0x120/0x1b8 vfs_write+0x2c8/0x388 ksys_write+0x74/0x108 __arm64_sys_write+0x24/0x38 el0_svc_common.constprop.0+0x64/0x148 do_el0_svc+0x24/0x38 el0_svc+0x3c/0x130 el0t_64_sync_handler+0xc8/0xd0 el0t_64_sync+0x1ac/0x1b0 ---[ end trace 0000000000000000 ]--- Since the enablement of sysfs mode is separeted into two critical regions, one for sysfs buffer allocation and another for hardware enablement, it's possible to race with the perf mode. Fix this by double check whether the perf mode's been used before enabling the hardware in sysfs mode. mode: [sysfs mode] [perf mode] tmc_etr_get_sysfs_buffer() spin_lock(&drvdata->spinlock) [sysfs buffer allocation] spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() drvdata->etr_buf = etr_perf->etr_buf spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() WARN_ON(drvdata->etr_buf) // WARN sicne etr_buf initialized at the perf side spin_unlock(&drvdata->spinlock) With this fix, we retain the check for CS_MODE_PERF in get_etr_sysfs_buf. This ensures we verify whether the perf mode's already running before we actually allocate the buffer. Then we can save the time of allocating/freeing the sysfs buffer if race with the perf mode.CVE-2026-46272