[PATCH AUTOSEL 6.1 06/15] powerpc/iommu: fix memory leak with using debugfs_lookup()

From: Sasha Levin
Date: Sun Mar 05 2023 - 08:55:01 EST


From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit b505063910c134778202dfad9332dfcecb76bab3 ]

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.

Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230202141919.2298821-1-gregkh@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/powerpc/kernel/iommu.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index caebe1431596e..ee95937bdaf14 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -67,11 +67,9 @@ static void iommu_debugfs_add(struct iommu_table *tbl)
static void iommu_debugfs_del(struct iommu_table *tbl)
{
char name[10];
- struct dentry *liobn_entry;

sprintf(name, "%08lx", tbl->it_index);
- liobn_entry = debugfs_lookup(name, iommu_debugfs_dir);
- debugfs_remove(liobn_entry);
+ debugfs_lookup_and_remove(name, iommu_debugfs_dir);
}
#else
static void iommu_debugfs_add(struct iommu_table *tbl){}
--
2.39.2