linux-kernel - [PATCH AUTOSEL 6.2 06/16] powerpc/iommu: fix memory leak with using debugfs

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Date:   Sun,  5 Mar 2023 08:51:57 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Sasha Levin <sashal@...nel.org>, aik@...abs.ru,
        christophe.leroy@...roup.eu, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH AUTOSEL 6.2 06/16] powerpc/iommu: fix memory leak with using debugfs_lookup()

From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

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