From e2ac55b6a8e337fac7cc59c6f452caac92ab5ee6 Mon Sep 17 00:00:00 2001 From: Chengyu Song Date: Tue, 14 Apr 2015 15:43:44 -0700 Subject: [PATCH] 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 Cc: Mark Fasheh Cc: Joel Becker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/cluster/heartbeat.c | 42 ++++++++++++++++++++++++++---------- fs/ocfs2/dlmglue.c | 2 +- fs/ocfs2/super.c | 9 ++++---- 3 files changed, 37 insertions(+), 16 deletions(-) diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c index 16eff45727ee..8e19b9d7aba8 100644 --- a/fs/ocfs2/cluster/heartbeat.c +++ b/fs/ocfs2/cluster/heartbeat.c @@ -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(®->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; } diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index 11849a44dc5a..23adcbf374d3 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -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"); diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 26675185b886..fb43de586791 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -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; } -- 2.39.5