[PATCH] block: partitions: of: Fix NULL dereference on partition without reg

[Loic Poulain]

A child node of a fixed-partitions node may lack a reg property, either
because it is malformed or because it is not a partition entry at all.
In that case of_get_property() returns NULL to reg, which is then
dereferenced without proper checking.

Fixes: 2e3a191e89f9 ("block: add support for partition table defined in OF")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxxxxxxxx>
---
 block/partitions/of.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/block/partitions/of.c b/block/partitions/of.c
index 53664ea06b6540e3d1155141adaafac7286f2d21..dab36513eba336344c9558d486a8915624b0fca8 100644
--- a/block/partitions/of.c
+++ b/block/partitions/of.c
@@ -15,6 +15,9 @@ static int validate_of_partition(struct device_node *np, int slot)
 	int a_cells = of_n_addr_cells(np);
 	int s_cells = of_n_size_cells(np);
 
+	if (!reg)
+		return -EINVAL;
+
 	/* Make sure reg len match the expected addr and size cells */
 	if (len / sizeof(*reg) != a_cells + s_cells)
 		return -EINVAL;

---
base-commit: fce2dfa773ced15f27dd27cd0b482a7473cdcf2a
change-id: 20260717-partition-null-b05e2c956ee7

Best regards,
-- 
Loic Poulain <loic.poulain@xxxxxxxxxxxxxxxx>