In the Linux kernel, the following vulnerability has been resolved:
powerpc/xive: propagate IPI init errors to prevent use-after-free
When xive_init_ipis() fails (e.g. irq_domain_alloc_irqs() fails),
the error path frees the global xive_ipis array. However,
xive_smp_probe() previously ignored this failure and proceeded to
call xive_setup_cpu_ipi(), which dereferences the already-freed
xive_ipis pointer -- a use-after-free. Now that xive_smp_probe() returns int (previous patch), propagate
the error from xive_init_ipis() and xive_setup_cpu_ipi() through
xive_smp_probe().
Check the return value in both pnv_smp_probe()
and pSeries_smp_probe() so that IPI setup is aborted cleanly on
failure, avoiding the use-after-free.
Attack Parameters
Attack Vector
Local
Requires local access
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1