From f555befd185dc097ede887eb7b308c2e1c1369d4 Mon Sep 17 00:00:00 2001 From: Jan Stancek Date: Tue, 12 Jan 2021 15:49:21 -0800 Subject: [PATCH] mm: migrate: initialize err in do_migrate_pages After commit 236c32eb1096 ("mm: migrate: clean up migrate_prep{_local}")', do_migrate_pages can return uninitialized variable 'err' (which is propagated to user-space as error) when 'from' and 'to' nodesets are identical. This can be reproduced with LTP migrate_pages01, which calls migrate_pages() with same set for both old/new_nodes. Add 'err' initialization back. Link: https://lkml.kernel.org/r/456a021c7ef3636d7668cec9dcb4a446a4244812.1609855564.git.jstancek@redhat.com Fixes: 236c32eb1096 ("mm: migrate: clean up migrate_prep{_local}") Signed-off-by: Jan Stancek Acked-by: Michal Hocko Acked-by: Yang Shi Cc: Zi Yan Cc: Jan Kara Cc: Matthew Wilcox Cc: Mel Gorman Cc: Song Liu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 8cf96bd21341..2c3a86502053 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1111,7 +1111,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, const nodemask_t *to, int flags) { int busy = 0; - int err; + int err = 0; nodemask_t tmp; migrate_prep(); -- GitLab