fuse: flush dirty data/metadata before non-truncate setattr
commit b24e7598 upstream. If writeback cache is enabled, then writes might get reordered with chmod/chown/utimes. The problem with this is that performing the write in the fuse daemon might itself change some of these attributes. In such case the following sequence of operations will result in file ending up with the wrong mode, for example: int fd = open ("suid", O_WRONLY|O_CREAT|O_EXCL); write (fd, "1", 1); fchown (fd, 0, 0); fchmod (fd, 04755); close (fd); This patch fixes this by flushing pending writes before performing chown/chmod/utimes. Reported-by:Giuseppe Scrivano <gscrivan@redhat.com> Tested-by:
Giuseppe Scrivano <gscrivan@redhat.com> Fixes: 4d99ff8f ("fuse: Turn writeback cache on") Cc: <stable@vger.kernel.org> # v3.15+ Signed-off-by:
Miklos Szeredi <mszeredi@redhat.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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