CVE-2024-36930

Published May 30, 2024

Last updated 2 years ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: spi: fix null pointer dereference within spi_sync If spi_sync() is called with the non-empty queue and the same spi_message is then reused, the complete callback for the message remains set while the context is cleared, leading to a null pointer dereference when the callback is invoked from spi_finalize_current_message(). With function inlining disabled, the call stack might look like this: _raw_spin_lock_irqsave from complete_with_flags+0x18/0x58 complete_with_flags from spi_complete+0x8/0xc spi_complete from spi_finalize_current_message+0xec/0x184 spi_finalize_current_message from spi_transfer_one_message+0x2a8/0x474 spi_transfer_one_message from __spi_pump_transfer_message+0x104/0x230 __spi_pump_transfer_message from __spi_transfer_message_noqueue+0x30/0xc4 __spi_transfer_message_noqueue from __spi_sync+0x204/0x248 __spi_sync from spi_sync+0x24/0x3c spi_sync from mcp251xfd_regmap_crc_read+0x124/0x28c [mcp251xfd] mcp251xfd_regmap_crc_read [mcp251xfd] from _regmap_raw_read+0xf8/0x154 _regmap_raw_read from _regmap_bus_read+0x44/0x70 _regmap_bus_read from _regmap_read+0x60/0xd8 _regmap_read from regmap_read+0x3c/0x5c regmap_read from mcp251xfd_alloc_can_err_skb+0x1c/0x54 [mcp251xfd] mcp251xfd_alloc_can_err_skb [mcp251xfd] from mcp251xfd_irq+0x194/0xe70 [mcp251xfd] mcp251xfd_irq [mcp251xfd] from irq_thread_fn+0x1c/0x78 irq_thread_fn from irq_thread+0x118/0x1f4 irq_thread from kthread+0xd8/0xf4 kthread from ret_from_fork+0x14/0x28 Fix this by also setting message->complete to NULL when the transfer is complete.
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

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