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| author | Miklos Szeredi <mszeredi@suse.cz> | 2014-01-22 19:36:57 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-13 13:47:59 -0800 |
| commit | d840f9899a6bc8bd88b3c87cd067ddf39a6ada45 (patch) | |
| tree | 4ef436e091d32ac9f01fe9c8fd87c02246cfd5c6 /fs/fuse | |
| parent | 329f4557c93a1aa769896155deefa363f01283e5 (diff) | |
| download | lwn-d840f9899a6bc8bd88b3c87cd067ddf39a6ada45.tar.gz lwn-d840f9899a6bc8bd88b3c87cd067ddf39a6ada45.zip | |
fuse: fix pipe_buf_operations
commit 28a625cbc2a14f17b83e47ef907b2658576a32aa upstream.
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 <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/fuse')
| -rw-r--r-- | fs/fuse/dev.c | 22 |
1 files changed, 5 insertions, 17 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 1d55f9465400..23bf1a52a5da 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++; |