lkml.org 
[lkml]   [2018]   [Sep]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 056/165] ipc/sem.c: prevent queue.status tearing in semop
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Davidlohr Bueso <dave@stgolabs.net>

[ Upstream commit f075faa300acc4f6301e348acde0a4580ed5f77c ]

In order for load/store tearing prevention to work, _all_ accesses to
the variable in question need to be done around READ and WRITE_ONCE()
macros. Ensure everyone does so for q->status variable for
semtimedop().

Link: http://lkml.kernel.org/r/20180717052654.676-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
ipc/sem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -2041,7 +2041,7 @@ static long do_semtimedop(int semid, str
}

do {
- queue.status = -EINTR;
+ WRITE_ONCE(queue.status, -EINTR);
queue.sleeper = current;

__set_current_state(TASK_INTERRUPTIBLE);

\
 
 \ /
  Last update: 2018-09-03 19:47    [W:0.450 / U:52.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site