[PATCH v2] configfs: Fix config_item refcnt error in __configfs_open_file()

From: gregkh
Date: Thu Mar 11 2021 - 06:36:03 EST


From: Daniel Rosenberg <drosen@xxxxxxxxxx>

__configfs_open_file() used to use configfs_get_config_item, but changed
in commit b0841eefd969 ("configfs: provide exclusion between IO and
removals") to just call to_item. The error path still tries to clean up
the reference, incorrectly decrementing the ref count.

Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: b0841eefd969 ("configfs: provide exclusion between IO and removals")
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
v2: goto the correct out_ label as pointed out by Christoph

fs/configfs/file.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/configfs/file.c b/fs/configfs/file.c
index 1f0270229d7b..da8351d1e455 100644
--- a/fs/configfs/file.c
+++ b/fs/configfs/file.c
@@ -378,7 +378,7 @@ static int __configfs_open_file(struct inode *inode, struct file *file, int type

attr = to_attr(dentry);
if (!attr)
- goto out_put_item;
+ goto out_free_buffer;

if (type & CONFIGFS_ITEM_BIN_ATTR) {
buffer->bin_attr = to_bin_attr(dentry);
@@ -391,7 +391,7 @@ static int __configfs_open_file(struct inode *inode, struct file *file, int type
/* Grab the module reference for this attribute if we have one */
error = -ENODEV;
if (!try_module_get(buffer->owner))
- goto out_put_item;
+ goto out_free_buffer;

error = -EACCES;
if (!buffer->item->ci_type)
@@ -435,8 +435,6 @@ static int __configfs_open_file(struct inode *inode, struct file *file, int type

out_put_module:
module_put(buffer->owner);
-out_put_item:
- config_item_put(buffer->item);
out_free_buffer:
up_read(&frag->frag_sem);
kfree(buffer);
--
2.30.2