From 9509941e9c534920ccc4771ae70bd6cbbe79df1c Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Sat, 12 Jan 2019 02:39:05 +0100 Subject: [PATCH] fuse: call pipe_buf_release() under pipe lock 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 Signed-off-by: Miklos Szeredi --- fs/fuse/dev.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index fc29264011a6..809c0f2f9942 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -2077,8 +2077,10 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, 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: kvfree(bufs);