From 9d3a39a5f1e45827b008fff1ee9cf3cac3409665 Mon Sep 17 00:00:00 2001
From: Khazhismel Kumykov <khazhy@google.com>
Date: Mon, 24 Aug 2020 15:10:34 -0700
Subject: [PATCH] block: grant IOPRIO_CLASS_RT to CAP_SYS_NICE
CAP_SYS_ADMIN is too broad, and ionice fits into CAP_SYS_NICE's grouping.
Retain CAP_SYS_ADMIN permission for backwards compatibility.
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/ioprio.c | 2 +-
include/uapi/linux/capability.h | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/block/ioprio.c b/block/ioprio.c
index 04ebd37966f18..364d2294ba904 100644
--- a/block/ioprio.c
+++ b/block/ioprio.c
@@ -69,7 +69,7 @@ int ioprio_check_cap(int ioprio)
switch (class) {
case IOPRIO_CLASS_RT:
- if (!capable(CAP_SYS_ADMIN))
+ if (!capable(CAP_SYS_NICE) && !capable(CAP_SYS_ADMIN))
return -EPERM;
fallthrough;
/* rt has prio field too */
diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h
index 395dd0df8d08d..c6ca330341471 100644
--- a/include/uapi/linux/capability.h
+++ b/include/uapi/linux/capability.h
@@ -288,6 +288,8 @@ struct vfs_ns_cap_data {
processes and setting the scheduling algorithm used by another
process. */
/* Allow setting cpu affinity on other processes */
+/* Allow setting realtime ioprio class */
+/* Allow setting ioprio class on other processes */
#define CAP_SYS_NICE 23
--
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