The patch titled Subject: mm: migrate: initialize err in do_migrate_pages has been added to the -mm tree. Its filename is mm-migrate-initialize-err-in-do_migrate_pages.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-migrate-initialize-err-in-do_migrate_pages.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-migrate-initialize-err-in-do_migrate_pages.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Jan Stancek <jstancek@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Fixes: 236c32eb1096 ("mm: migrate: clean up migrate_prep{_local}") Signed-off-by: Jan Stancek <jstancek@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Yang Shi <shy828301@xxxxxxxxx> Cc: Zi Yan <ziy@xxxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Song Liu <songliubraving@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mempolicy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/mempolicy.c~mm-migrate-initialize-err-in-do_migrate_pages +++ a/mm/mempolicy.c @@ -1111,7 +1111,7 @@ int do_migrate_pages(struct mm_struct *m const nodemask_t *to, int flags) { int busy = 0; - int err; + int err = 0; nodemask_t tmp; migrate_prep(); _ Patches currently in -mm which might be from jstancek@xxxxxxxxxx are mm-migrate-initialize-err-in-do_migrate_pages.patch