| Message ID | 20230202142022.2300096-1-gregkh@linuxfoundation.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/slub: fix memory leak with using debugfs_lookup() | expand |
On Thu, Feb 02, 2023 at 03:20:22PM +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. > > Cc: Christoph Lameter <cl@linux.com> > Cc: Pekka Enberg <penberg@kernel.org> > Cc: David Rientjes <rientjes@google.com> > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: Roman Gushchin <roman.gushchin@linux.dev> > Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > --- > mm/slub.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/slub.c b/mm/slub.c > index 13459c69095a..4880e461fcc5 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -6449,7 +6449,7 @@ static void debugfs_slab_add(struct kmem_cache *s) > > void debugfs_slab_release(struct kmem_cache *s) > { > - debugfs_remove_recursive(debugfs_lookup(s->name, slab_debugfs_root)); > + debugfs_lookup_and_remove(s->name, slab_debugfs_root); > } Looks good to me. Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Thank you for fixing this. > static int __init slab_debugfs_init(void) > -- > 2.39.1 >
On Thu, Feb 02, 2023 at 03:20:22PM +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. > > Cc: Christoph Lameter <cl@linux.com> > Cc: Pekka Enberg <penberg@kernel.org> > Cc: David Rientjes <rientjes@google.com> > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: Roman Gushchin <roman.gushchin@linux.dev> > Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Good catch! Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Thanks!
On Thu, 2 Feb 2023, 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. > > Cc: Christoph Lameter <cl@linux.com> > Cc: Pekka Enberg <penberg@kernel.org> > Cc: David Rientjes <rientjes@google.com> > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: Roman Gushchin <roman.gushchin@linux.dev> > Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: David Rientjes <rientjes@google.com>
On 2/2/23 15:20, 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. > > Cc: Christoph Lameter <cl@linux.com> > Cc: Pekka Enberg <penberg@kernel.org> > Cc: David Rientjes <rientjes@google.com> > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: Roman Gushchin <roman.gushchin@linux.dev> > Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Thanks, added to slab/for-6.3/fixes > --- > mm/slub.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/slub.c b/mm/slub.c > index 13459c69095a..4880e461fcc5 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -6449,7 +6449,7 @@ static void debugfs_slab_add(struct kmem_cache *s) > > void debugfs_slab_release(struct kmem_cache *s) > { > - debugfs_remove_recursive(debugfs_lookup(s->name, slab_debugfs_root)); > + debugfs_lookup_and_remove(s->name, slab_debugfs_root); > } > > static int __init slab_debugfs_init(void)
diff --git a/mm/slub.c b/mm/slub.c index 13459c69095a..4880e461fcc5 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -6449,7 +6449,7 @@ static void debugfs_slab_add(struct kmem_cache *s) void debugfs_slab_release(struct kmem_cache *s) { - debugfs_remove_recursive(debugfs_lookup(s->name, slab_debugfs_root)); + debugfs_lookup_and_remove(s->name, slab_debugfs_root); } static int __init slab_debugfs_init(void)
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: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- mm/slub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)