powerpc/iommu: fix memory leak with using debugfs_lookup()

[ 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@linuxfoundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230202141919.2298821-1-gregkh@linuxfoundation.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index caebe14..ee95937 100644 (file)
--- 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){}