CVE-2026-31597 — Vulnetix

CVE-2026-31597 PUBLISHED CVSS 9.300000190734863 CRITICAL

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY filemap_fault() may drop the mmap_lock before returning VM_FAULT_RETRY, as documented in mm/filemap.c: "If our return value has VM_FAULT_RETRY set, it's because the mmap_lock may be dropped before doing I/O or by lock_folio_maybe_drop_mmap()." When this happens, a concurrent munmap() can call remove_vma() and free the vm_area_struct via RCU. The saved 'vma' pointer in ocfs2_fault() then becomes a dangling pointer, and the subsequent trace_ocfs2_fault() call dereferences it -- a use-after-free. Fix this by saving ip_blkno as a plain integer before calling filemap_fault(), and removing vma from the trace event. Since ip_blkno is copied by value before the lock can be dropped, it remains valid regardless of what happens to the vma or inode afterward.

Risk Scores

CVSS v4.0

9.300000190734863

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Affected Products

Vendor	Product	Versions
Linux	Linux	1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 6.12.83, *
linux	linux_kernel	0, 0, 0

Timeline

Apr 24, 2026 CVE Published
Apr 24, 2026 Security Advisory
Apr 27, 2026 Security Advisory
Apr 29, 2026 CVE Updated

References

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