1 files changed, 16 insertions, 2 deletions

diff --git a/fs/ioprio.c b/fs/ioprio.c
index 748cfb92dcc6..2f7d05c89922 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -111,12 +111,14 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
         read_lock(&tasklist_lock);
         switch (which) {
                 case IOPRIO_WHO_PROCESS:
+                        rcu_read_lock();
                         if (!who)
                                 p = current;
                         else
                                 p = find_task_by_vpid(who);
                         if (p)
                                 ret = set_task_ioprio(p, ioprio);
+                        rcu_read_unlock();
                         break;
                 case IOPRIO_WHO_PGRP:
                         if (!who)
@@ -139,7 +141,12 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
                                 break;
 
                         do_each_thread(g, p) {
-                                if (__task_cred(p)->uid != who)
+                                int match;
+
+                                rcu_read_lock();
+                                match = __task_cred(p)->uid == who;
+                                rcu_read_unlock();
+                                if (!match)
                                         continue;
                                 ret = set_task_ioprio(p, ioprio);
                                 if (ret)
@@ -200,12 +207,14 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
         read_lock(&tasklist_lock);
         switch (which) {
                 case IOPRIO_WHO_PROCESS:
+                        rcu_read_lock();
                         if (!who)
                                 p = current;
                         else
                                 p = find_task_by_vpid(who);
                         if (p)
                                 ret = get_task_ioprio(p);
+                        rcu_read_unlock();
                         break;
                 case IOPRIO_WHO_PGRP:
                         if (!who)
@@ -232,7 +241,12 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
                                 break;
 
                         do_each_thread(g, p) {
-                                if (__task_cred(p)->uid != user->uid)
+                                int match;
+
+                                rcu_read_lock();
+                                match = __task_cred(p)->uid == user->uid;
+                                rcu_read_unlock();
+                                if (!match)
                                         continue;
                                 tmpio = get_task_ioprio(p);
                                 if (tmpio < 0)