[PATCH v2] of_numa: fix uninitialized memory nodes causing kernel panic
From: Yin Tirui
Date: Sat Aug 16 2025 - 03:37:51 EST
When the number of CPUs is fewer than the number of memory nodes,
some memory nodes may not be properly initialized because they are
not added to numa_nodes_parsed during memory parsing.
In of_numa_parse_memory_nodes(), after successfully adding a memory
block via numa_add_memblk(), the corresponding node ID should be
marked as parsed. However, the current implementation in numa_add_memblk()
only adds the memory block to numa_meminfo but fails to update
numa_nodes_parsed, leaving some nodes uninitialized.
During boot in a QEMU-emulated ARM64 NUMA environment, the kernel
panics when free_area_init() attempts to access NODE_DATA() for
memory nodes that were uninitialized.
[ 0.000000] Call trace:
[ 0.000000] free_area_init+0x620/0x106c (P)
[ 0.000000] bootmem_init+0x110/0x1dc
[ 0.000000] setup_arch+0x278/0x60c
[ 0.000000] start_kernel+0x70/0x748
[ 0.000000] __primary_switched+0x88/0x90
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 767507654c22 ("arch_numa: switch over to numa_memblks")
Signed-off-by: Yin Tirui <yintirui@xxxxxxxxxx>
---
v2: Move the changes to the of_numa related. Correct the fixes tag.
---
drivers/of/of_numa.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c
index 230d5f628c1b..cd2dc8e825c9 100644
--- a/drivers/of/of_numa.c
+++ b/drivers/of/of_numa.c
@@ -59,8 +59,11 @@ static int __init of_numa_parse_memory_nodes(void)
r = -EINVAL;
}
- for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++)
+ for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++) {
r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1);
+ if (!r)
+ node_set(nid, numa_nodes_parsed);
+ }
if (!i || r) {
of_node_put(np);
--
2.43.0