lkml.org 
[lkml]   [2020]   [May]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL 4.14 16/39] configfs: fix config_item refcnt leak in configfs_rmdir()
Date
From: Xiyu Yang <xiyuyang19@fudan.edu.cn>

[ Upstream commit 8aebfffacfa379ba400da573a5bf9e49634e38cb ]

configfs_rmdir() invokes configfs_get_config_item(), which returns a
reference of the specified config_item object to "parent_item" with
increased refcnt.

When configfs_rmdir() returns, local variable "parent_item" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
configfs_rmdir(). When down_write_killable() fails, the function forgets
to decrease the refcnt increased by configfs_get_config_item(), causing
a refcnt leak.

Fix this issue by calling config_item_put() when down_write_killable()
fails.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/configfs/dir.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index c2ef617d2f97d..c875f246cb0e9 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1537,6 +1537,7 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
spin_lock(&configfs_dirent_lock);
configfs_detach_rollback(dentry);
spin_unlock(&configfs_dirent_lock);
+ config_item_put(parent_item);
return -EINTR;
}
frag->frag_dead = true;
--
2.20.1
\
 
 \ /
  Last update: 2020-05-14 20:55    [W:0.154 / U:0.404 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site