vmalloc: back off when the current task is killed

__vmalloc_area_node() allocates pages to cover the requested vmalloc size. This can be a lot of memory. If the current task is killed by the OOM killer, and thus has an unlimited access to memory reserves, it can consume all the memory theoretically. Fix this by checking for fatal_signal_pending and back off early. Link: http:https://lkml.kernel.org/r/[email protected] Signed-off-by: Michal Hocko <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Al Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
SELinuxProject · Feb 25, 2017 · 5d17a73 · 5d17a73
1 parent dbe43d4
commit 5d17a73
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
@@ -1642,6 +1642,11 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
  for (i = 0; i < area->nr_pages; i++) {
  struct page *page;
 
+ if (fatal_signal_pending(current)) {
+ area->nr_pages = i;
+ goto fail;
+ }
+
  if (node == NUMA_NO_NODE)
  page = alloc_page(alloc_mask);
  else