Vulnerabilities > CVE-2023-52516 - Improper Locking vulnerability in Linux Kernel

047910
CVSS 5.5 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
local
low complexity
linux
CWE-667
NVD
Published: 2024-03-02
Updated: 2024-12-11

Summary

In the Linux kernel, the following vulnerability has been resolved: dma-debug: don't call __dma_entry_alloc_check_leak() under free_entries_lock __dma_entry_alloc_check_leak() calls into printk -> serial console output (qcom geni) and grabs port->lock under free_entries_lock spin lock, which is a reverse locking dependency chain as qcom_geni IRQ handler can call into dma-debug code and grab free_entries_lock under port->lock. Move __dma_entry_alloc_check_leak() call out of free_entries_lock scope so that we don't acquire serial console's port->lock under it. Trimmed-down lockdep splat: The existing dependency chain (in reverse order) is: -> #2 (free_entries_lock){-.-.}-{2:2}: _raw_spin_lock_irqsave+0x60/0x80 dma_entry_alloc+0x38/0x110 debug_dma_map_page+0x60/0xf8 dma_map_page_attrs+0x1e0/0x230 dma_map_single_attrs.constprop.0+0x6c/0xc8 geni_se_rx_dma_prep+0x40/0xcc qcom_geni_serial_isr+0x310/0x510 __handle_irq_event_percpu+0x110/0x244 handle_irq_event_percpu+0x20/0x54 handle_irq_event+0x50/0x88 handle_fasteoi_irq+0xa4/0xcc handle_irq_desc+0x28/0x40 generic_handle_domain_irq+0x24/0x30 gic_handle_irq+0xc4/0x148 do_interrupt_handler+0xa4/0xb0 el1_interrupt+0x34/0x64 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x64/0x68 arch_local_irq_enable+0x4/0x8 ____do_softirq+0x18/0x24 ... -> #1 (&port_lock_key){-.-.}-{2:2}: _raw_spin_lock_irqsave+0x60/0x80 qcom_geni_serial_console_write+0x184/0x1dc console_flush_all+0x344/0x454 console_unlock+0x94/0xf0 vprintk_emit+0x238/0x24c vprintk_default+0x3c/0x48 vprintk+0xb4/0xbc _printk+0x68/0x90 register_console+0x230/0x38c uart_add_one_port+0x338/0x494 qcom_geni_serial_probe+0x390/0x424 platform_probe+0x70/0xc0 really_probe+0x148/0x280 __driver_probe_device+0xfc/0x114 driver_probe_device+0x44/0x100 __device_attach_driver+0x64/0xdc bus_for_each_drv+0xb0/0xd8 __device_attach+0xe4/0x140 device_initial_probe+0x1c/0x28 bus_probe_device+0x44/0xb0 device_add+0x538/0x668 of_device_add+0x44/0x50 of_platform_device_create_pdata+0x94/0xc8 of_platform_bus_create+0x270/0x304 of_platform_populate+0xac/0xc4 devm_of_platform_populate+0x60/0xac geni_se_probe+0x154/0x160 platform_probe+0x70/0xc0 ... -> #0 (console_owner){-...}-{0:0}: __lock_acquire+0xdf8/0x109c lock_acquire+0x234/0x284 console_flush_all+0x330/0x454 console_unlock+0x94/0xf0 vprintk_emit+0x238/0x24c vprintk_default+0x3c/0x48 vprintk+0xb4/0xbc _printk+0x68/0x90 dma_entry_alloc+0xb4/0x110 debug_dma_map_sg+0xdc/0x2f8 __dma_map_sg_attrs+0xac/0xe4 dma_map_sgtable+0x30/0x4c get_pages+0x1d4/0x1e4 [msm] msm_gem_pin_pages_locked+0x38/0xac [msm] msm_gem_pin_vma_locked+0x58/0x88 [msm] msm_ioctl_gem_submit+0xde4/0x13ac [msm] drm_ioctl_kernel+0xe0/0x15c drm_ioctl+0x2e8/0x3f4 vfs_ioctl+0x30/0x50 ... Chain exists of: console_owner --> &port_lock_key --> free_entries_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(free_entries_lock); lock(&port_lock_key); lock(free_entries_lock); lock(console_owner); *** DEADLOCK *** Call trace: dump_backtrace+0xb4/0xf0 show_stack+0x20/0x30 dump_stack_lvl+0x60/0x84 dump_stack+0x18/0x24 print_circular_bug+0x1cc/0x234 check_noncircular+0x78/0xac __lock_acquire+0xdf8/0x109c lock_acquire+0x234/0x284 console_flush_all+0x330/0x454 consol ---truncated---

Vulnerable Configurations

Part Description Count
OS
Linux
5380

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Leveraging Race Conditions
    This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
  • Leveraging Race Conditions via Symbolic Links
    This attack leverages the use of symbolic links (Symlinks) in order to write to sensitive files. An attacker can create a Symlink link to a target file not otherwise accessible to her. When the privileged program tries to create a temporary file with the same name as the Symlink link, it will actually write to the target file pointed to by the attackers' Symlink link. If the attacker can insert malicious content in the temporary file she will be writing to the sensitive file by using the Symlink. The race occurs because the system checks if the temporary file exists, then creates the file. The attacker would typically create the Symlink during the interval between the check and the creation of the temporary file.

References