This is a note to let you know that I've just added the patch titled Allow stack to grow up to address space limit to the 4.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: allow-stack-to-grow-up-to-address-space-limit.patch and it can be found in the queue-4.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bd726c90b6b8ce87602208701b208a208e6d5600 Mon Sep 17 00:00:00 2001 From: Helge Deller <deller@xxxxxx> Date: Mon, 19 Jun 2017 17:34:05 +0200 Subject: Allow stack to grow up to address space limit From: Helge Deller <deller@xxxxxx> commit bd726c90b6b8ce87602208701b208a208e6d5600 upstream. Fix expand_upwards() on architectures with an upward-growing stack (parisc, metag and partly IA-64) to allow the stack to reliably grow exactly up to the address space limit given by TASK_SIZE. Signed-off-by: Helge Deller <deller@xxxxxx> Acked-by: Hugh Dickins <hughd@xxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/mmap.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2228,16 +2228,19 @@ int expand_upwards(struct vm_area_struct if (!(vma->vm_flags & VM_GROWSUP)) return -EFAULT; - /* Guard against wrapping around to address 0. */ + /* Guard against exceeding limits of the address space. */ address &= PAGE_MASK; - address += PAGE_SIZE; - if (!address) + if (address >= TASK_SIZE) return -ENOMEM; + address += PAGE_SIZE; /* Enforce stack_guard_gap */ gap_addr = address + stack_guard_gap; - if (gap_addr < address) - return -ENOMEM; + + /* Guard against overflow */ + if (gap_addr < address || gap_addr > TASK_SIZE) + gap_addr = TASK_SIZE; + next = vma->vm_next; if (next && next->vm_start < gap_addr) { if (!(next->vm_flags & VM_GROWSUP)) Patches currently in stable-queue which might be from deller@xxxxxx are queue-4.11/allow-stack-to-grow-up-to-address-space-limit.patch queue-4.11/mm-larger-stack-guard-gap-between-vmas.patch