CVE-2026-46268 PCI/P2PDMA: Fix p2pmem_alloc_mmap() warning condition
A logic error in the Linux kernel PCI/P2PDMA driver triggers a warning when debug VM options are enabled, potentially causing system instability.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-46268?
CVE-2026-46268 is a medium-severity vulnerability in Linux kernel, published on 3 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-46268?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46268?
Apply the vendor's patch.
Is CVE-2026-46268 being exploited?
There is no known exploitation of CVE-2026-46268 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-46268, DEBIAN-CVE-2026-46268, GHSA-9f46-h8mj-93v5, UBUNTU-CVE-2026-46268.