CVE-2024-26605 PCI/ASPM: Fix deadlock when enabling ASPM
A race condition in the Linux kernel PCI/ASPM subsystem can cause a deadlock during device probe, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-26605?
CVE-2024-26605 is a medium-severity vulnerability in Linux kernel, published on 24 Feb 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:
PCI/ASPM: Fix deadlock when enabling ASPM
A last minute revert in 6.7-final introduced a potential deadlock when enabling ASPM during probe of Qualcomm PCIe controllers as reported by lockdep:
============================================ WARNING: possible recursive locking detected 6.7.0 #40 Not tainted -------------------------------------------- kworker/u16:5/90 is trying to acquire lock: ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pcie_aspm_pm_state_change+0x58/0xdc
but task is already holding lock: ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pci_walk_bus+0x34/0xbc
other info that might help us debug this: Possible unsafe locking scenario:
CPU0 ---- lock(pci_bus_sem); lock(pci_bus_sem);
*** DEADLOCK ***
Call trace: print_deadlock_bug+0x25c/0x348 __lock_acquire+0x10a4/0x2064 lock_acquire+0x1e8/0x318 down_read+0x60/0x184 pcie_aspm_pm_state_change+0x58/0xdc pci_set_full_power_state+0xa8/0x114 pci_set_power_state+0xc4/0x120 qcom_pcie_enable_aspm+0x1c/0x3c [pcie_qcom] pci_walk_bus+0x64/0xbc qcom_pcie_host_post_init_2_7_0+0x28/0x34 [pcie_qcom]
The deadlock can easily be reproduced on machines like the Lenovo ThinkPad X13s by adding a delay to increase the race window during asynchronous probe where another thread can take a write lock.
Add a new pci_set_power_state_locked() and associated helper functions that can be called with the PCI bus semaphore held to avoid taking the read lock twice.
Weakness: CWE-667
Which versions are affected by CVE-2024-26605?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-26605?
Apply the vendor's patch.
Is CVE-2024-26605 being exploited?
There is no known exploitation of CVE-2024-26605 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-26605, DEBIAN-CVE-2024-26605, GHSA-5p3m-pw6j-5jwm, ROOT-OS-UBUNTU-2204-CVE-2024-26605, UBUNTU-CVE-2024-26605.