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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
b9c370b61d735a0e5390c42771e7eb21413f7868 to < 0f7908a016c092cfdaa16d785fa5099d867bc1a3affected8cc22ba3f77c59df5f1ac47d62df51efb28cd868 to < b0f4478838be1f1d330061201898fef65bf8fd7caffectedf93e71aea6c60ebff8adbd8941e678302d377869 to < ef90508574d7af48420bdc5f7b9a4f1cdd26bc70affectedf93e71aea6c60ebff8adbd8941e678302d377869 to < 1e560864159d002b453da42bd2c13a1805515a20affected1f2f662c8bec75d1311e063efaa9107435cf16c8affected6.1.72 to < 6.1.88affected6.6.11 to < 6.6.29affected5.15.147 to < 5.16affected
Linux Linux
Default version status: affected
6.7affected0 to < 6.7unaffected6.1.88 to ≤ 6.1.*unaffected6.6.29 to ≤ 6.6.*unaffected6.7.5 to ≤ 6.7.*unaffected6.8 to ≤ *unaffected