From: Sourav Panda <souravpanda@google.com>
To: muchun.song@linux.dev, osalvador@suse.de, akpm@linux-foundation.org
Cc: david@kernel.org, surenb@google.com, fvdl@google.com,
gthelen@google.com, souravpanda@google.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] mm/hugetlb: Fix null pointer dereference of nodemask in hugetlb_cma_alloc_frozen_folio
Date: Thu, 2 Jul 2026 21:57:13 +0000 [thread overview]
Message-ID: <20260702215713.627941-1-souravpanda@google.com> (raw)
alloc_buddy_hugetlb_folio_with_mpol() can pass a NULL nodemask to
hugetlb_cma_alloc_frozen_folio() as a fallback to allocate from all
nodes. In this case, hugetlb_cma_alloc_frozen_folio() blindly
dereferences it in for_each_node_mask(), leading to a null pointer
dereference.
Fix this by checking if nodemask is NULL and defaulting to
node_states[N_MEMORY] if it is.
Signed-off-by: Sourav Panda <souravpanda@google.com>
---
mm/hugetlb_cma.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/hugetlb_cma.c b/mm/hugetlb_cma.c
index 39344d6c78d8..563e11e607e5 100644
--- a/mm/hugetlb_cma.c
+++ b/mm/hugetlb_cma.c
@@ -34,6 +34,9 @@ struct folio *hugetlb_cma_alloc_frozen_folio(int order, gfp_t gfp_mask,
if (!hugetlb_cma_size)
return NULL;
+ if (!nodemask)
+ nodemask = &node_states[N_MEMORY];
+
if (hugetlb_cma[nid])
page = cma_alloc_frozen_compound(hugetlb_cma[nid], order);
--
2.55.0.rc0.799.gd6f94ed593-goog
next reply other threads:[~2026-07-03 0:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-02 21:57 Sourav Panda [this message]
2026-07-02 23:24 ` [PATCH] mm/hugetlb: Fix null pointer dereference of nodemask in hugetlb_cma_alloc_frozen_folio Andrew Morton
2026-07-03 20:04 ` Sourav Panda
2026-07-04 3:04 ` Muchun Song
2026-07-04 3:53 ` Sourav Panda
2026-07-04 4:06 ` Muchun Song
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