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authorDan Carpenter <dan.carpenter@oracle.com>2021-06-28 19:34:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-29 10:53:46 -0700
commit54e948c60cc843b6e84dc44496edc91f51d2a28e (patch)
tree8646317910cb0caee63fd930ef3e02d6222dea88 /fs
parent74ef829e41be8ada93e1d1dfa681c11be338c8d5 (diff)
ocfs2: fix snprintf() checking
The snprintf() function returns the number of bytes which would have been printed if the buffer was large enough. In other words it can return ">= remain" but this code assumes it returns "== remain". The run time impact of this bug is not very severe. The next iteration through the loop would trigger a WARN() when we pass a negative limit to snprintf(). We would then return success instead of -E2BIG. The kernel implementation of snprintf() will never return negatives so there is no need to check and I have deleted that dead code. Link: https://lkml.kernel.org/r/20210511135350.GV1955@kadam Fixes: a860f6eb4c6a ("ocfs2: sysfile interfaces for online file check") Fixes: 74ae4e104dfc ("ocfs2: Create stack glue sysfs files.") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/ocfs2/filecheck.c6
-rw-r--r--fs/ocfs2/stackglue.c8
2 files changed, 3 insertions, 11 deletions
diff --git a/fs/ocfs2/filecheck.c b/fs/ocfs2/filecheck.c
index 90b8d300c1ee..de56e6231af8 100644
--- a/fs/ocfs2/filecheck.c
+++ b/fs/ocfs2/filecheck.c
@@ -326,11 +326,7 @@ static ssize_t ocfs2_filecheck_attr_show(struct kobject *kobj,
ret = snprintf(buf + total, remain, "%lu\t\t%u\t%s\n",
p->fe_ino, p->fe_done,
ocfs2_filecheck_error(p->fe_status));
- if (ret < 0) {
- total = ret;
- break;
- }
- if (ret == remain) {
+ if (ret >= remain) {
/* snprintf() didn't fit */
total = -E2BIG;
break;
diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c
index d50e8b8dfea4..16f1bfc407f2 100644
--- a/fs/ocfs2/stackglue.c
+++ b/fs/ocfs2/stackglue.c
@@ -500,11 +500,7 @@ static ssize_t ocfs2_loaded_cluster_plugins_show(struct kobject *kobj,
list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
ret = snprintf(buf, remain, "%s\n",
p->sp_name);
- if (ret < 0) {
- total = ret;
- break;
- }
- if (ret == remain) {
+ if (ret >= remain) {
/* snprintf() didn't fit */
total = -E2BIG;
break;
@@ -531,7 +527,7 @@ static ssize_t ocfs2_active_cluster_plugin_show(struct kobject *kobj,
if (active_stack) {
ret = snprintf(buf, PAGE_SIZE, "%s\n",
active_stack->sp_name);
- if (ret == PAGE_SIZE)
+ if (ret >= PAGE_SIZE)
ret = -E2BIG;
}
spin_unlock(&ocfs2_stack_lock);