[PATCH] iommu: apple-dart: fix potential null pointer deref
From: Qasim Ijaz
Date: Fri Mar 14 2025 - 19:01:32 EST
If kzalloc() fails, accessing cfg->supports_bypass causes a null pointer dereference.
Fix by checking for NULL immediately after allocation and returning -ENOMEM.
Fixes: 3bc0102835f6 ("iommu: apple-dart: Allow mismatched bypass support")
Signed-off-by: Qasim Ijaz <qasdev00@xxxxxxxxx>
---
drivers/iommu/apple-dart.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index 13ccb801f52a..e13501541fdd 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -797,12 +797,11 @@ static int apple_dart_of_xlate(struct device *dev,
if (!cfg) {
cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
-
+ if (!cfg)
+ return -ENOMEM;
/* Will be ANDed with DART capabilities */
cfg->supports_bypass = true;
}
- if (!cfg)
- return -ENOMEM;
dev_iommu_priv_set(dev, cfg);
cfg_dart = cfg->stream_maps[0].dart;
--
2.39.5