[12/23] lustre: sysfs: error-check value stored in jobid_var

Commit Message

James Simmons Aug. 11, 2020, 12:20 p.m. UTC

From: Mr NeilBrown <[e-mail]>

The jobid_var sysfs attribute only has 3 meaningful values.
Other values cause lustre_get_jobid() to return an error
which is uniformly ignored.

To improve usability and resilience, check that the value
written is acceptable before storing it.

Reviewed-by: James Simmons <[e-mail]>
Signed-off-by: Mr NeilBrown <[e-mail]>
---
 fs/lustre/obdclass/obd_sysfs.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

Patch

diff --git a/fs/lustre/obdclass/obd_sysfs.c b/fs/lustre/obdclass/obd_sysfs.c
index cb2f0a9..5fc638f 100644
--- a/fs/lustre/obdclass/obd_sysfs.c
+++ b/fs/lustre/obdclass/obd_sysfs.c
@@ -225,16 +225,26 @@  static ssize_t jobid_var_store(struct kobject *kobj, struct attribute *attr,
 			       const char *buffer,
 			       size_t count)
 {
+	static const char * const valid[] = {
+		JOBSTATS_DISABLE,
+		JOBSTATS_PROCNAME_UID,
+		JOBSTATS_NODELOCAL,
+		JOBSTATS_SESSION,
+		NULL
+	};
+	int i;
+
 	if (!count || count > JOBSTATS_JOBID_VAR_MAX_LEN)
 		return -EINVAL;
 
-	memset(obd_jobid_var, 0, JOBSTATS_JOBID_VAR_MAX_LEN + 1);
-
-	memcpy(obd_jobid_var, buffer, count);
+	for (i = 0; valid[i]; i++)
+		if (sysfs_streq(buffer, valid[i]))
+			break;
+	if (!valid[i])
+		return -EINVAL;
 
-	/* Trim the trailing '\n' if any */
-	if (obd_jobid_var[count - 1] == '\n')
-		obd_jobid_var[count - 1] = 0;
+	memset(obd_jobid_var, 0, JOBSTATS_JOBID_VAR_MAX_LEN + 1);
+	strcpy(obd_jobid_var, valid[i]);
 
 	return count;
 }