These patches include few backported fixes for the 4.4 stable tree. I would appreciate if you could kindly consider including them in the next release. Ajay --- [Changes from v2]: Merged following changes from Vlastimil's series [1]: - Added page_ref_count() in [Patch v3 5/8] - Added missing refcount overflow checks on x86 and s390 [Patch v3 5/8] - Added [Patch v3 8/8] - Removed 7aef4172c795 i.e. [Patch v2 3/8] [1] https://lore.kernel.org/stable/20191108093814.16032-1-vbabka@xxxxxxx/ --- [PATCH v3 1/8]: Backporting of upstream commit f958d7b528b1: mm: make page ref count overflow check tighter and more explicit [PATCH v3 2/8]: Backporting of upstream commit 88b1a17dfc3e: mm: add 'try_get_page()' helper function [PATCH v3 3/8]: Backporting of upstream commit a3e328556d41: mm, gup: remove broken VM_BUG_ON_PAGE compound check for hugepages [PATCH v3 4/8]: Backporting of upstream commit d63206ee32b6: mm, gup: ensure real head page is ref-counted when using hugepages [PATCH v3 5/8]: Backporting of upstream commit 8fde12ca79af: mm: prevent get_user_pages() from overflowing page refcount [PATCH v3 6/8]: Backporting of upstream commit 7bf2d1df8082: pipe: add pipe_buf_get() helper [PATCH v3 7/8]: Backporting of upstream commit 15fab63e1e57: fs: prevent page refcount overflow in pipe_buf_get [PATCH v3 8/8]: x86, mm, gup: prevent get_page() race with munmap in paravirt guest