From 28a625cbc2a14f17b83e47ef907b2658576a32aa Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 22 Jan 2014 19:36:57 +0100 Subject: fuse: fix pipe_buf_operations Having this struct in module memory could Oops when if the module is unloaded while the buffer still persists in a pipe. Since sock_pipe_buf_ops is essentially the same as fuse_dev_pipe_buf_steal merge them into nosteal_pipe_buf_ops (this is the same as default_pipe_buf_ops except stealing the page from the buffer is not allowed). Reported-by: Al Viro Signed-off-by: Miklos Szeredi Cc: stable@vger.kernel.org --- fs/fuse/dev.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-) (limited to 'fs/fuse') diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index ef74ad5fd362..fa8cb4b7b8fe 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1296,22 +1296,6 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov, return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs)); } -static int fuse_dev_pipe_buf_steal(struct pipe_inode_info *pipe, - struct pipe_buffer *buf) -{ - return 1; -} - -static const struct pipe_buf_operations fuse_dev_pipe_buf_ops = { - .can_merge = 0, - .map = generic_pipe_buf_map, - .unmap = generic_pipe_buf_unmap, - .confirm = generic_pipe_buf_confirm, - .release = generic_pipe_buf_release, - .steal = fuse_dev_pipe_buf_steal, - .get = generic_pipe_buf_get, -}; - static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) @@ -1358,7 +1342,11 @@ static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos, buf->page = bufs[page_nr].page; buf->offset = bufs[page_nr].offset; buf->len = bufs[page_nr].len; - buf->ops = &fuse_dev_pipe_buf_ops; + /* + * Need to be careful about this. Having buf->ops in module + * code can Oops if the buffer persists after module unload. + */ + buf->ops = &nosteal_pipe_buf_ops; pipe->nrbufs++; page_nr++; -- cgit v1.2.3