| From 9509941e9c534920ccc4771ae70bd6cbbe79df1c Mon Sep 17 00:00:00 2001 |
| From: Jann Horn <jannh@google.com> |
| Date: Sat, 12 Jan 2019 02:39:05 +0100 |
| Subject: fuse: call pipe_buf_release() under pipe lock |
| |
| From: Jann Horn <jannh@google.com> |
| |
| commit 9509941e9c534920ccc4771ae70bd6cbbe79df1c upstream. |
| |
| Some of the pipe_buf_release() handlers seem to assume that the pipe is |
| locked - in particular, anon_pipe_buf_release() accesses pipe->tmp_page |
| without taking any extra locks. From a glance through the callers of |
| pipe_buf_release(), it looks like FUSE is the only one that calls |
| pipe_buf_release() without having the pipe locked. |
| |
| This bug should only lead to a memory leak, nothing terrible. |
| |
| Fixes: dd3bb14f44a6 ("fuse: support splice() writing to fuse device") |
| Cc: stable@vger.kernel.org |
| Signed-off-by: Jann Horn <jannh@google.com> |
| Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/fuse/dev.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/fs/fuse/dev.c |
| +++ b/fs/fuse/dev.c |
| @@ -2024,8 +2024,10 @@ static ssize_t fuse_dev_splice_write(str |
| |
| ret = fuse_dev_do_write(fud, &cs, len); |
| |
| + pipe_lock(pipe); |
| for (idx = 0; idx < nbuf; idx++) |
| pipe_buf_release(pipe, &bufs[idx]); |
| + pipe_unlock(pipe); |
| |
| out: |
| kfree(bufs); |
