2023-02-02 14:19:31

by Greg Kroah-Hartman

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

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 <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Alexey Kardashevskiy <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
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

2023-02-15 12:43:21

by Michael Ellerman

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

On Thu, 2 Feb 2023 15:19:19 +0100, Greg Kroah-Hartman wrote:
> 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.
>
>

Applied to powerpc/next.

[1/1] ppc: iommu: fix memory leak with using debugfs_lookup()
https://git.kernel.org/powerpc/c/b505063910c134778202dfad9332dfcecb76bab3

cheers