| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 056/165] ipc/sem.c: prevent queue.status tearing in semop | Date | Mon, 3 Sep 2018 18:55:42 +0200 |
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4.14-stable review patch. If anyone has any objections, please let me know.
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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);
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