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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2021-06-29 05:34:01 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-20 17:21:01 +0300 |
| commit | 23044e81e87f0f5d8d96162ea1e6bf3cabd6b81d (patch) | |
| tree | a035edb48c2192d616648d45e51c2b97a17464bc /fs/ocfs2 | |
| parent | a4567b9318d8c510d9fef01f5f13db6d4083eb16 (diff) | |
| download | linux-23044e81e87f0f5d8d96162ea1e6bf3cabd6b81d.tar.xz | |
ocfs2: fix snprintf() checking
[ Upstream commit 54e948c60cc843b6e84dc44496edc91f51d2a28e ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/ocfs2')
| -rw-r--r-- | fs/ocfs2/filecheck.c | 6 | ||||
| -rw-r--r-- | fs/ocfs2/stackglue.c | 8 |
2 files changed, 3 insertions, 11 deletions
diff --git a/fs/ocfs2/filecheck.c b/fs/ocfs2/filecheck.c index 2cabbcf2f28e..5571268b681c 100644 --- a/fs/ocfs2/filecheck.c +++ b/fs/ocfs2/filecheck.c @@ -431,11 +431,7 @@ static ssize_t ocfs2_filecheck_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 52c07346bea3..03e1c6cd6f3c 100644 --- a/fs/ocfs2/stackglue.c +++ b/fs/ocfs2/stackglue.c @@ -510,11 +510,7 @@ 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; @@ -541,7 +537,7 @@ 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); |