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authorLinus Torvalds <torvalds@linux-foundation.org>2021-12-10 14:15:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-12-10 14:15:39 -0800
commit0d21e6684779493d90f3dee90d4457d5b4aed8ad (patch)
tree8b4beb5cc8d10ecdd64cd16d653891349aa2c946 /kernel
parentb9172f9e88446f3ede07594752c70555a2aee33f (diff)
parent4b3749865374899e115aa8c48681709b086fe6d3 (diff)
downloadlinux-0d21e6684779493d90f3dee90d4457d5b4aed8ad.tar.bz2
Merge tag 'aio-poll-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux
Pull aio poll fixes from Eric Biggers: "Fix three bugs in aio poll, and one issue with POLLFREE more broadly: - aio poll didn't handle POLLFREE, causing a use-after-free. - aio poll could block while the file is ready. - aio poll called eventfd_signal() when it isn't allowed. - POLLFREE didn't handle multiple exclusive waiters correctly. This has been tested with the libaio test suite, as well as with test programs I wrote that reproduce the first two bugs. I am sending this pull request myself as no one seems to be maintaining this code" * tag 'aio-poll-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: aio: Fix incorrect usage of eventfd_signal_allowed() aio: fix use-after-free due to missing POLLFREE handling aio: keep poll requests on waitqueue until completed signalfd: use wake_up_pollfree() binder: use wake_up_pollfree() wait: add wake_up_pollfree()
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched/wait.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 76577d1642a5..eca38107b32f 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -238,6 +238,13 @@ void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode)
}
EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
+void __wake_up_pollfree(struct wait_queue_head *wq_head)
+{
+ __wake_up(wq_head, TASK_NORMAL, 0, poll_to_key(EPOLLHUP | POLLFREE));
+ /* POLLFREE must have cleared the queue. */
+ WARN_ON_ONCE(waitqueue_active(wq_head));
+}
+
/*
* Note: we use "set_current_state()" _after_ the wait-queue add,
* because we need a memory barrier there on SMP, so that any