In the Linux kernel, the following vulnerability has been resolved:
powerpc/eeh: Fix recursive locking on devices without EEH sensitive driver
The commit 1010b4c012b0 ("powerpc/eeh: Make EEH driver device hotplug
safe") refactored the EEH code such that the pci_rescan_remove_lock is
held at the beginning of eeh_handle_normal_event() and the
eeh_reset_device() is called with that lock being held. Looks like the
commit missed to remove the existing lock/unlock inside eeh_rmv_device()
which is no longer necessary. This is causing the eehd to hang on the
lock which it actually holds when that code path is taken.
[<0>] 0xc00000011c78f870
[<0>] __switch_to+0xfc/0x1a0
[<0>] pci_lock_rescan_remove+0x30/0x44
[<0>] eeh_rmv_device+0x290/0x2e0
[<0>] eeh_pe_dev_traverse+0x80/0x130
[<0>] eeh_reset_device+0xcc/0x23c
[<0>] eeh_handle_normal_event+0x830/0xa80
[<0>] eeh_event_handler+0xf8/0x190
[<0>] kthread+0x194/0x1b0
[<0>] start_kernel_thread+0x14/0x18
The issue is seen for cases where the errors are detected on the PHB
directly AND|OR for devices where the driver error_detected() returns
PCI_ERS_RESULT_NEED_RESET, and driver being not EEH sensitive(i.e no
error handlers like slot_reset(), resume() etc defined).