From: Davidlohr Bueso <dave@xxxxxxxxxxxx> Subject: ipc/sem.c: prevent queue.status tearing in semop 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@xxxxxxxxxxxx Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx> Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- ipc/sem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/ipc/sem.c~ipc-sem-prevent-queuestatus-tearing-in-semop +++ a/ipc/sem.c @@ -2118,7 +2118,7 @@ static long do_semtimedop(int semid, str } do { - queue.status = -EINTR; + WRITE_ONCE(queue.status, -EINTR); queue.sleeper = current; __set_current_state(TASK_INTERRUPTIBLE); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
