CVE-2026-46268

Summary

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

PCI/P2PDMA: Fix p2pmem_alloc_mmap() warning condition

Commit b7e282378773 has already changed the initial page refcount of p2pdma page from one to zero, however, in p2pmem_alloc_mmap() it uses "VM_WARN_ON_ONCE_PAGE(!page_ref_count(page))" to assert the initial page refcount should not be zero and the following will be reported when CONFIG_DEBUG_VM is enabled:

page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x380400000 flags: 0x20000000002000(reserved|node=0|zone=4) raw: 0020000000002000 ff1100015e3ab440 0000000000000000 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: VM_WARN_ON_ONCE_PAGE(!page_ref_count(page)) ————[ cut here ]———— WARNING: CPU: 5 PID: 449 at drivers/pci/p2pdma.c:240 p2pmem_alloc_mmap+0x83a/0xa60

Fix by using "page_ref_count(page)" as the assertion condition.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb7e2823787735ca009e63f35f164b46df0ef096c < eb9aa9f8010465d927864f5a35bdc5604b0ff51aaffected
LinuxLinuxb7e2823787735ca009e63f35f164b46df0ef096c < 9b69243983fb2f4d4d1f4ef0989bc1296547dc2caffected
LinuxLinuxb7e2823787735ca009e63f35f164b46df0ef096c < cb500023a75246f60b79af9f7321d6e75330c5b5affected
LinuxLinux6.15affected
LinuxLinux0 < 6.15unaffected
LinuxLinux6.18.14 <= 6.18.*unaffected
LinuxLinux6.19.4 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References