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| author | Jens Axboe <axboe@kernel.dk> | 2025-01-08 10:28:05 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-01-17 13:40:58 +0100 |
| commit | a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7 (patch) | |
| tree | 55da08598d2ef695590070a9c4f9a873e232d56a /io_uring | |
| parent | cbb64f5d757fe18e5ac7a6ffb67e8264f2992996 (diff) | |
| download | linux-a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7.tar.gz linux-a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7.tar.bz2 linux-a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7.zip | |
io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period
Commit c9a40292a44e78f71258b8522655bffaf5753bdb upstream.
io_eventfd_do_signal() is invoked from an RCU callback, but when
dropping the reference to the io_ev_fd, it calls io_eventfd_free()
directly if the refcount drops to zero. This isn't correct, as any
potential freeing of the io_ev_fd should be deferred another RCU grace
period.
Just call io_eventfd_put() rather than open-code the dec-and-test and
free, which will correctly defer it another RCU grace period.
Fixes: 21a091b970cd ("io_uring: signal registered eventfd to process deferred task work")
Reported-by: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/eventfd.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/io_uring/eventfd.c b/io_uring/eventfd.c index e37fddd5d9ce..ffc4bd17d078 100644 --- a/io_uring/eventfd.c +++ b/io_uring/eventfd.c @@ -38,7 +38,7 @@ static void io_eventfd_do_signal(struct rcu_head *rcu) eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE); if (refcount_dec_and_test(&ev_fd->refs)) - io_eventfd_free(rcu); + call_rcu(&ev_fd->rcu, io_eventfd_free); } void io_eventfd_signal(struct io_ring_ctx *ctx) |