CVE-2026-45880

In the Linux kernel, the following vulnerability has been resolved:

PCI/P2PDMA: Release per-CPU pgmap ref when vm_insert_page() fails

When vm_insert_page() fails in p2pmem_alloc_mmap(), p2pmem_alloc_mmap()
doesn’t invoke percpu_ref_put() to free the per-CPU ref of pgmap acquired
after gen_pool_alloc_owner(), and memunmap_pages() will hang forever when
trying to remove the PCI device.

Fix it by adding the missed percpu_ref_put().

More information : https://git.kernel.org/stable/c/51b7181cfbedf289ce794b6d97a1c596c309ec38