[PATCH] ppc: iommu: fix memory leak with using debugfs_lookup()

From: Greg Kroah-Hartman
Date: Thu Feb 02 2023 - 09:19:31 EST


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.

Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Alexey Kardashevskiy <aik@xxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 caebe1431596..ee95937bdaf1 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){}
--
2.39.1