diff options
| author | David Howells <dhowells@redhat.com> | 2019-10-07 16:30:51 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2019-11-15 16:22:54 +0000 |
| commit | 8df441294dd34fb0b16b45f550f55e96db6af4dc (patch) | |
| tree | 7dc49acddd4b6585d146bbab6c24062237bf5407 /fs/pipe.c | |
| parent | 7e25a73f1a52b58fc8206557e40d990cd791ad25 (diff) | |
| download | lwn-8df441294dd34fb0b16b45f550f55e96db6af4dc.tar.gz lwn-8df441294dd34fb0b16b45f550f55e96db6af4dc.zip | |
pipe: Check for ring full inside of the spinlock in pipe_write()
Make pipe_write() check to see if the ring has become full between it
taking the pipe mutex, checking the ring status and then taking the
spinlock.
This can happen if a notification is written into the pipe as that happens
without the pipe mutex.
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/pipe.c')
| -rw-r--r-- | fs/pipe.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index d7b8d3f22987..aba2455caabe 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -463,6 +463,11 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) spin_lock_irq(&pipe->wait.lock); head = pipe->head; + if (pipe_full(head, pipe->tail, max_usage)) { + spin_unlock_irq(&pipe->wait.lock); + continue; + } + pipe->head = head + 1; /* Always wake up, even if the copy fails. Otherwise |