[PATCH v2 3/8] block: use new capable_or functionality

Christian Göttsche cgzones at googlemail.com
Mon May 2 16:00:24 UTC 2022


Use the new added capable_or function in appropriate cases, where a task
is required to have any of two capabilities.

Reorder CAP_SYS_ADMIN last.

Fixes: 94c4b4fd25e6 ("block: Check ADMIN before NICE for IOPRIO_CLASS_RT")

Signed-off-by: Christian Göttsche <cgzones at googlemail.com>
---
 block/ioprio.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/block/ioprio.c b/block/ioprio.c
index 2fe068fcaad5..52d5da286323 100644
--- a/block/ioprio.c
+++ b/block/ioprio.c
@@ -37,14 +37,7 @@ int ioprio_check_cap(int ioprio)
 
 	switch (class) {
 		case IOPRIO_CLASS_RT:
-			/*
-			 * Originally this only checked for CAP_SYS_ADMIN,
-			 * which was implicitly allowed for pid 0 by security
-			 * modules such as SELinux. Make sure we check
-			 * CAP_SYS_ADMIN first to avoid a denial/avc for
-			 * possibly missing CAP_SYS_NICE permission.
-			 */
-			if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_NICE))
+			if (!capable_or(CAP_SYS_NICE, CAP_SYS_ADMIN))
 				return -EPERM;
 			fallthrough;
 			/* rt has prio field too */
-- 
2.36.0



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