ocfs2: 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.
This patch tries to solve this problem by fixing certain checks. However,
I have that found other call sites are protected by #ifdef CONFIG_DEBUG_FS.
In current implementation, if CONFIG_DEBUG_FS is defined, then the above
two functions will never return any ERROR_VALUE. So another possibility
to fix this is to surround all the buggy checks/functions with the same
#ifdef CONFIG_DEBUG_FS. But I'm not sure if this would break any functionality,
as only OCFS2_FS_STATS declares dependency on DEBUG_FS.
Signed-off-by: Chengyu Song <csong84@gatech.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 2667518..fb43de5 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1112,7 +1112,7 @@
osb->osb_debug_root = debugfs_create_dir(osb->uuid_str,
ocfs2_debugfs_root);
- if (!osb->osb_debug_root) {
+ if (IS_ERR_OR_NULL(osb->osb_debug_root)) {
status = -EINVAL;
mlog(ML_ERROR, "Unable to create per-mount debugfs root.\n");
goto read_super_error;
@@ -1122,7 +1122,7 @@
osb->osb_debug_root,
osb,
&ocfs2_osb_debug_fops);
- if (!osb->osb_ctxt) {
+ if (IS_ERR_OR_NULL(osb->osb_ctxt)) {
status = -EINVAL;
mlog_errno(status);
goto read_super_error;
@@ -1606,8 +1606,9 @@
}
ocfs2_debugfs_root = debugfs_create_dir("ocfs2", NULL);
- if (!ocfs2_debugfs_root) {
- status = -ENOMEM;
+ if (IS_ERR_OR_NULL(ocfs2_debugfs_root)) {
+ status = ocfs2_debugfs_root ?
+ PTR_ERR(ocfs2_debugfs_root) : -ENOMEM;
mlog(ML_ERROR, "Unable to create ocfs2 debugfs root.\n");
goto out4;
}