Commit e2ac55b6 authored by Chengyu Song's avatar Chengyu Song Committed by Linus Torvalds
Browse files

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: default avatarChengyu Song <csong84@gatech.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 762515a8

fs/ocfs2/cluster/heartbeat.c

+31 −11
Original line number Diff line number Diff line
@@ -1312,7 +1312,9 @@ static int o2hb_debug_init(void) 
	int ret = -ENOMEM;



	o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL);

	if (!o2hb_debug_dir) {

	if (IS_ERR_OR_NULL(o2hb_debug_dir)) {

		ret = o2hb_debug_dir ?

			PTR_ERR(o2hb_debug_dir) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}
@@ -1325,7 +1327,9 @@ static int o2hb_debug_init(void) 
						 sizeof(o2hb_live_node_bitmap),

						 O2NM_MAX_NODES,

						 o2hb_live_node_bitmap);

	if (!o2hb_debug_livenodes) {

	if (IS_ERR_OR_NULL(o2hb_debug_livenodes)) {

		ret = o2hb_debug_livenodes ?

			PTR_ERR(o2hb_debug_livenodes) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}
@@ -1338,7 +1342,9 @@ static int o2hb_debug_init(void) 
						   sizeof(o2hb_live_region_bitmap),

						   O2NM_MAX_REGIONS,

						   o2hb_live_region_bitmap);

	if (!o2hb_debug_liveregions) {

	if (IS_ERR_OR_NULL(o2hb_debug_liveregions)) {

		ret = o2hb_debug_liveregions ?

			PTR_ERR(o2hb_debug_liveregions) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}
@@ -1352,7 +1358,9 @@ static int o2hb_debug_init(void) 
					  sizeof(o2hb_quorum_region_bitmap),

					  O2NM_MAX_REGIONS,

					  o2hb_quorum_region_bitmap);

	if (!o2hb_debug_quorumregions) {

	if (IS_ERR_OR_NULL(o2hb_debug_quorumregions)) {

		ret = o2hb_debug_quorumregions ?

			PTR_ERR(o2hb_debug_quorumregions) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}
@@ -1366,7 +1374,9 @@ static int o2hb_debug_init(void) 
					  sizeof(o2hb_failed_region_bitmap),

					  O2NM_MAX_REGIONS,

					  o2hb_failed_region_bitmap);

	if (!o2hb_debug_failedregions) {

	if (IS_ERR_OR_NULL(o2hb_debug_failedregions)) {

		ret = o2hb_debug_failedregions ?

			PTR_ERR(o2hb_debug_failedregions) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}
@@ -2000,7 +2010,8 @@ static int o2hb_debug_region_init(struct o2hb_region *reg, struct dentry *dir) 


	reg->hr_debug_dir =

		debugfs_create_dir(config_item_name(&reg->hr_item), dir);

	if (!reg->hr_debug_dir) {

	if (IS_ERR_OR_NULL(reg->hr_debug_dir)) {

		ret = reg->hr_debug_dir ? PTR_ERR(reg->hr_debug_dir) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}
@@ -2013,7 +2024,9 @@ static int o2hb_debug_region_init(struct o2hb_region *reg, struct dentry *dir) 
					  O2HB_DB_TYPE_REGION_LIVENODES,

					  sizeof(reg->hr_live_node_bitmap),

					  O2NM_MAX_NODES, reg);

	if (!reg->hr_debug_livenodes) {

	if (IS_ERR_OR_NULL(reg->hr_debug_livenodes)) {

		ret = reg->hr_debug_livenodes ?

			PTR_ERR(reg->hr_debug_livenodes) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}
@@ -2025,7 +2038,9 @@ static int o2hb_debug_region_init(struct o2hb_region *reg, struct dentry *dir) 
					  sizeof(*(reg->hr_db_regnum)),

					  O2HB_DB_TYPE_REGION_NUMBER,

					  0, O2NM_MAX_NODES, reg);

	if (!reg->hr_debug_regnum) {

	if (IS_ERR_OR_NULL(reg->hr_debug_regnum)) {

		ret = reg->hr_debug_regnum ?

			PTR_ERR(reg->hr_debug_regnum) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}
@@ -2037,7 +2052,9 @@ static int o2hb_debug_region_init(struct o2hb_region *reg, struct dentry *dir) 
					  sizeof(*(reg->hr_db_elapsed_time)),

					  O2HB_DB_TYPE_REGION_ELAPSED_TIME,

					  0, 0, reg);

	if (!reg->hr_debug_elapsed_time) {

	if (IS_ERR_OR_NULL(reg->hr_debug_elapsed_time)) {

		ret = reg->hr_debug_elapsed_time ?

			PTR_ERR(reg->hr_debug_elapsed_time) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}
@@ -2049,13 +2066,16 @@ static int o2hb_debug_region_init(struct o2hb_region *reg, struct dentry *dir) 
					  sizeof(*(reg->hr_db_pinned)),

					  O2HB_DB_TYPE_REGION_PINNED,

					  0, 0, reg);

	if (!reg->hr_debug_pinned) {

	if (IS_ERR_OR_NULL(reg->hr_debug_pinned)) {

		ret = reg->hr_debug_pinned ?

			PTR_ERR(reg->hr_debug_pinned) : -ENOMEM;

		mlog_errno(ret);

		goto bail;

	}



	ret = 0;

	return 0;

bail:

	debugfs_remove_recursive(reg->hr_debug_dir);

	return ret;

}

fs/ocfs2/dlmglue.c

+1 −1
Original line number Diff line number Diff line
@@ -2954,7 +2954,7 @@ static int ocfs2_dlm_init_debug(struct ocfs2_super *osb) 
							 osb->osb_debug_root,

							 osb,

							 &ocfs2_dlm_debug_fops);

	if (!dlm_debug->d_locking_state) {

	if (IS_ERR_OR_NULL(dlm_debug->d_locking_state)) {

		ret = -EINVAL;

		mlog(ML_ERROR,

		     "Unable to create locking state debugfs file.\n");

fs/ocfs2/super.c

+5 −4
Original line number Diff line number Diff line
@@ -1112,7 +1112,7 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent) 


	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 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent) 
					    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 @@ static int __init ocfs2_init(void) 
	}



	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;

	}

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