lkml.org 
[lkml]   [2015]   [Apr]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 8/9] gfs2: incorrect check for debugfs returns
Date
From: Chengyu Song <csong84@gatech.edu>

debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
is not configured, so the return value should be checked against ERROR_VALUE
as well, otherwise the later dereference of the dentry pointer would crash
the kernel.

Signed-off-by: Chengyu Song <csong84@gatech.edu>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
---
fs/gfs2/glock.c | 47 ++++++++++++++++++++++++++++-------------------
1 file changed, 28 insertions(+), 19 deletions(-)

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index f42dffb..0fa8062 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -2047,34 +2047,41 @@ static const struct file_operations gfs2_sbstats_fops = {

int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
{
- sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
- if (!sdp->debugfs_dir)
- return -ENOMEM;
- sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
- S_IFREG | S_IRUGO,
- sdp->debugfs_dir, sdp,
- &gfs2_glocks_fops);
- if (!sdp->debugfs_dentry_glocks)
+ struct dentry *dent;
+
+ dent = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
+ if (IS_ERR_OR_NULL(dent))
+ goto fail;
+ sdp->debugfs_dir = dent;
+
+ dent = debugfs_create_file("glocks",
+ S_IFREG | S_IRUGO,
+ sdp->debugfs_dir, sdp,
+ &gfs2_glocks_fops);
+ if (IS_ERR_OR_NULL(dent))
goto fail;
+ sdp->debugfs_dentry_glocks = dent;

- sdp->debugfs_dentry_glstats = debugfs_create_file("glstats",
- S_IFREG | S_IRUGO,
- sdp->debugfs_dir, sdp,
- &gfs2_glstats_fops);
- if (!sdp->debugfs_dentry_glstats)
+ dent = debugfs_create_file("glstats",
+ S_IFREG | S_IRUGO,
+ sdp->debugfs_dir, sdp,
+ &gfs2_glstats_fops);
+ if (IS_ERR_OR_NULL(dent))
goto fail;
+ sdp->debugfs_dentry_glstats = dent;

- sdp->debugfs_dentry_sbstats = debugfs_create_file("sbstats",
- S_IFREG | S_IRUGO,
- sdp->debugfs_dir, sdp,
- &gfs2_sbstats_fops);
- if (!sdp->debugfs_dentry_sbstats)
+ dent = debugfs_create_file("sbstats",
+ S_IFREG | S_IRUGO,
+ sdp->debugfs_dir, sdp,
+ &gfs2_sbstats_fops);
+ if (IS_ERR_OR_NULL(dent))
goto fail;
+ sdp->debugfs_dentry_sbstats = dent;

return 0;
fail:
gfs2_delete_debugfs_file(sdp);
- return -ENOMEM;
+ return dent ? PTR_ERR(dent) : -ENOMEM;
}

void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
@@ -2100,6 +2107,8 @@ void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
int gfs2_register_debugfs(void)
{
gfs2_root = debugfs_create_dir("gfs2", NULL);
+ if (IS_ERR(gfs2_root))
+ return PTR_ERR(gfs2_root);
return gfs2_root ? 0 : -ENOMEM;
}

--
1.9.3


\
 
 \ /
  Last update: 2015-04-13 17:41    [W:0.057 / U:0.904 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site