gfs2: incorrect check for debugfs returns

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>
This commit is contained in:
Chengyu Song 2015-03-24 09:37:53 -05:00 committed by Bob Peterson
parent d9be0cda77
commit 7b4ddfa7c9

View file

@ -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)
goto fail;
struct dentry *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_dir(sdp->sd_table_name, gfs2_root);
if (IS_ERR_OR_NULL(dent))
goto fail;
sdp->debugfs_dir = 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("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;
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;
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;
}