From: Greg Kroah-Hartman gregkh@linuxfoundation.org
debugfs_lookup() Date: Fri, 2 Sep 2022 14:56:31 +0200 [thread overview] Message-ID: 20220902125631.128329-1-gregkh@linuxfoundation.org (raw)
When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. Fix this up by properly calling dput().
Fixes: 75c1c2b53c78b ("mm/damon/dbgfs: support multiple contexts") Cc: stable@vger.kernel.org # 5.15.x Cc: SeongJae Park sj@kernel.org Cc: Andrew Morton akpm@linux-foundation.org Cc: damon@lists.linux.dev Cc: linux-mm@kvack.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: SeongJae Park sj@kernel.org --- Changes from v1 (https://lore.kernel.org/damon/20220902125631.128329-1-gregkh@linuxfoundation...) - Call dput() for failure-return case (Andrew Morton)
mm/damon/dbgfs.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c index 3b55a1b219b5..652a94deafe3 100644 --- a/mm/damon/dbgfs.c +++ b/mm/damon/dbgfs.c @@ -884,6 +884,7 @@ static int dbgfs_rm_context(char *name) struct dentry *root, *dir, **new_dirs; struct damon_ctx **new_ctxs; int i, j; + int ret = 0;
if (damon_nr_running_ctxs()) return -EBUSY; @@ -898,14 +899,16 @@ static int dbgfs_rm_context(char *name)
new_dirs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_dirs), GFP_KERNEL); - if (!new_dirs) - return -ENOMEM; + if (!new_dirs) { + ret = -ENOMEM; + goto out_dput; + }
new_ctxs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_ctxs), GFP_KERNEL); if (!new_ctxs) { - kfree(new_dirs); - return -ENOMEM; + ret = -ENOMEM; + goto out_new_dirs; }
for (i = 0, j = 0; i < dbgfs_nr_ctxs; i++) { @@ -925,7 +928,13 @@ static int dbgfs_rm_context(char *name) dbgfs_ctxs = new_ctxs; dbgfs_nr_ctxs--;
- return 0; + goto out_dput; + +out_new_dirs: + kfree(new_dirs); +out_dput: + dput(dir); + return ret; }
static ssize_t dbgfs_rm_context_write(struct file *file,