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.
https://git.kernel.org/stable/c/c554a8d376d5aea1b237ed6bef6f9fbfc550e67f
https://git.kernel.org/stable/c/411a3c016e7a95f5fa105a0587e07d0647a77727