[PATCH] knfsd: nfsd: call nfsd_setuser() on fh_compose(), fix nfsd4 permissions problem
In the typical v2/v3 case the only new filehandles used as arguments to operations are filehandles taken directly off the wire, which don't get dentries until fh_verify() is called. But in v4 the filehandles that are arguments to operations were often created by previous operations (putrootfh, lookup, etc.) using fh_compose, which sets the dentry in the filehandle without calling nfsd_setuser(). This also means that, for example, if filesystem B is mounted on filesystem A, and filesystem A is exported without root-squashing, then a client can bypass the rootsquashing on B using a compound that starts at a filehandle in A, crosses into B using lookups, and then does stuff in B. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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