dequeue_hugetlb_folio_nodemask() expects a preferred node where to get the hugetlb page from. It does not expect, though, users to pass NUMA_NO_NODE, otherwise we will get trash when trying to get the zonelist from that node. All current users are careful enough to not pass NUMA_NO_NODE, but it opens the door for new users to get this wrong since it is not documented [0]. Guard against this by getting the local nid if NUMA_NO_NODE was passed. [0] https://lore.kernel.org/linux-mm/0000000000004f12bb061a9acf07@xxxxxxxxxx/ Closes: https://lore.kernel.org/linux-mm/0000000000004f12bb061a9acf07@xxxxxxxxxx/ Reported-and-tested-by: syzbot+569ed13f4054f271087b@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Oscar Salvador <osalvador@xxxxxxx> --- mm/hugetlb.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3518321f6598..6a5ea898e4da 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1355,6 +1355,10 @@ static struct folio *dequeue_hugetlb_folio_nodemask(struct hstate *h, gfp_t gfp_ struct zoneref *z; int node = NUMA_NO_NODE; + /* 'nid' should not be NUMA_NO_NODE. Try to catch any misuse of it and rectifiy. */ + if (nid == NUMA_NO_NODE) + nid = numa_node_id(); + zonelist = node_zonelist(nid, gfp_mask); retry_cpuset: -- 2.45.2
