Hi, this series backports the CVE-2019-11487 fixes (page refcount overflow) to 4.4 stable. It differs from Ajay's series [1] in the following: - gup.c variants of fast gup for x86 and s390 are fixed too. I've not fixed sparc, mips, sh. It's unlikely the known overflow scenario based on FUSE, which needs 140GB of RAM, is a problem for those architectures, and I don't feel confident enough to patch them. I've sent the same fixup for 4.9 [3] - there are some differences in backport adaptations, hopefully not important. My version is taken from our 4.4 based kernel, which was just simpler for me than adding the missing parts to Ajay's version - The last patch fixes another problem in the fast gup implementation on x86, that I've previously posted and got merged to 4.9 stable [2]. [1] https://lore.kernel.org/linux-mm/1570581863-12090-1-git-send-email-akaher@xxxxxxxxxx/ [2] https://lore.kernel.org/linux-mm/20190802160614.8089-1-vbabka@xxxxxxx/ [3] https://lore.kernel.org/linux-mm/9c130fa4-e52d-f8bd-c450-42341c7ab441@xxxxxxx/ Linus Torvalds (3): mm: make page ref count overflow check tighter and more explicit mm: add 'try_get_page()' helper function mm: prevent get_user_pages() from overflowing page refcount Matthew Wilcox (1): fs: prevent page refcount overflow in pipe_buf_get Miklos Szeredi (1): pipe: add pipe_buf_get() helper Punit Agrawal (1): mm, gup: ensure real head page is ref-counted when using hugepages Vlastimil Babka (1): x86, mm, gup: prevent get_page() race with munmap in paravirt guest Will Deacon (1): mm, gup: remove broken VM_BUG_ON_PAGE compound check for hugepages arch/s390/mm/gup.c | 6 +++-- arch/x86/mm/gup.c | 23 ++++++++++++++++++- fs/fuse/dev.c | 12 +++++----- fs/pipe.c | 4 ++-- fs/splice.c | 12 ++++++++-- include/linux/mm.h | 26 ++++++++++++++++++++- include/linux/pipe_fs_i.h | 17 ++++++++++++-- kernel/trace/trace.c | 6 ++++- mm/gup.c | 48 +++++++++++++++++++++++++++------------ mm/huge_memory.c | 2 +- mm/hugetlb.c | 18 +++++++++++++-- mm/internal.h | 17 ++++++++++---- 12 files changed, 152 insertions(+), 39 deletions(-) -- 2.23.0
