[PATCH] Fix prlimit64 for suid/sgid processes

[Kacper Kornet <kornet@camk.edu.pl>]

Since check_prlimit_permission always fails in the case of SUID/GUID
processes, such processes are not able to read or set their own limits.
This commit changes this by assuming that process can always read/change
its own limits.

Signed-off-by: Kacper Kornet <kornet@camk.edu.pl>
---
 kernel/sys.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/kernel/sys.c b/kernel/sys.c
index e9ad444..0aaafde 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1409,10 +1409,12 @@ SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
 		rcu_read_unlock();
 		return -ESRCH;
 	}
-	ret = check_prlimit_permission(tsk);
-	if (ret) {
-		rcu_read_unlock();
-		return ret;
+	if (tsk != current) {
+		ret = check_prlimit_permission(tsk);
+		if (ret) {
+			rcu_read_unlock();
+			return ret;
+		}
 	}
 	get_task_struct(tsk);
 	rcu_read_unlock();
-- 
  Kacper Kornet