Description
In the Linux kernel, the following vulnerability has been resolved: mm/userfaultfd: fix kmap_local LIFO ordering for CONFIG_HIGHPTE With CONFIG_HIGHPTE on 32-bit ARM, move_pages_pte() maps PTE pages using kmap_local_page(), which requires unmapping in Last-In-First-Out order. The current code maps dst_pte first, then src_pte, but unmaps them in the same order (dst_pte, src_pte), violating the LIFO requirement. This causes the warning in kunmap_local_indexed(): WARNING: CPU: 0 PID: 604 at mm/highmem.c:622 kunmap_local_indexed+0x178/0x17c addr \!= __fix_to_virt(FIX_KMAP_BEGIN + idx) Fix this by reversing the unmap order to respect LIFO ordering. This issue follows the same pattern as similar fixes: - commit eca6828403b8 ("crypto: skcipher - fix mismatch between mapping and unmapping order") - commit 8cf57c6df818 ("nilfs2: eliminate staggered calls to kunmap in nilfs_rename") Both of which addressed the same fundamental requirement that kmap_local operations must follow LIFO ordering.
Product status
adef440691bab824e39c1b17382322d195e1fab0 before b051f707018967ea8f697d790a1ed8c443f63812
adef440691bab824e39c1b17382322d195e1fab0 before bd1ee62759d0bd4d6b909731c076c230ac89d61e
adef440691bab824e39c1b17382322d195e1fab0 before 9614d8bee66387501f48718fa306e17f2aa3f2f3
6.8
Any version before 6.8
6.12.46
6.16.6
6.17
References
git.kernel.org/...c/b051f707018967ea8f697d790a1ed8c443f63812
git.kernel.org/...c/bd1ee62759d0bd4d6b909731c076c230ac89d61e
git.kernel.org/...c/9614d8bee66387501f48718fa306e17f2aa3f2f3
