cvedb.io
CVE-2026-45837
HIGH · CVSS 7.8
EPSS exploitation probability: 0%
Published 2026-05-27T11:16:23.020 · Last modified 2026-06-26T19:09:14.590

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix use-after-free in arena_vm_close on fork arena_vm_open() only bumps vml->mmap_count but never registers the child VMA in arena->vma_list. The vml->vma always points at the parent VMA, so after parent munmap the pointer dangles. If the child then calls bpf_arena_free_pages(), zap_pages() reads the stale vml->vma triggering use-after-free. Fix this by preventing the arena VMA from being inherited across fork with VM_DONTCOPY, and preventing VMA splits via the may_split callback. Also reject mremap with a .mremap callback returning -EINVAL. A same-size mremap(MREMAP_FIXED) on the full arena VMA reaches copy_vma() through the following path: check_prep_vma() - returns 0 early: new_len == old_len

Affected products

linux — linux_kernel

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.