The patch titled
knfsd: nfsd: call nfsd_setuser() on fh_compose(), fix nfsd4 permissions problem
has been added to the -mm tree. Its filename is
knfsd-nfsd-call-nfsd_setuser-on-fh_compose-fix-nfsd4-permissions-problem.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: knfsd: nfsd: call nfsd_setuser() on fh_compose(), fix nfsd4 permissions problem
From: J. Bruce Fields <bfields@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/nfsd/nfsfh.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff -puN fs/nfsd/nfsfh.c~knfsd-nfsd-call-nfsd_setuser-on-fh_compose-fix-nfsd4-permissions-problem fs/nfsd/nfsfh.c
--- a/fs/nfsd/nfsfh.c~knfsd-nfsd-call-nfsd_setuser-on-fh_compose-fix-nfsd4-permissions-problem
+++ a/fs/nfsd/nfsfh.c
@@ -187,13 +187,6 @@ fh_verify(struct svc_rqst *rqstp, struct
goto out;
}
- /* Set user creds for this exportpoint */
- error = nfsd_setuser(rqstp, exp);
- if (error) {
- error = nfserrno(error);
- goto out;
- }
-
/*
* Look up the dentry using the NFS file handle.
*/
@@ -251,6 +244,14 @@ fh_verify(struct svc_rqst *rqstp, struct
}
cache_get(&exp->h);
+ /* Set user creds for this exportpoint; necessary even in the "just
+ * checking" case because this may be a filehandle that was created by
+ * fh_compose, and that is about to be used in another nfsv4 compound
+ * operation */
+ error = nfserrno(nfsd_setuser(rqstp, exp));
+ if (error)
+ goto out;
+
error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
if (error)
goto out;
_
Patches currently in -mm which might be from bfields@xxxxxxxxxxxxxx are
origin.patch
knfsd-nfsd4-fix-open_confirm-locking.patch
knfsd-nfsd-call-nfsd_setuser-on-fh_compose-fix-nfsd4-permissions-problem.patch
knfsd-nfsd4-remove-superfluous-grace-period-checks.patch
knfsd-nfsd-fix-misplaced-fh_unlock-in-nfsd_link.patch
knfsd-svcrpc-gss-simplify-rsc_parse.patch
knfsd-nfsd4-fix-some-open-argument-tests.patch
knfsd-nfsd4-fix-open-flag-passing.patch
knfsd-svcrpc-simplify-nfsd-rpcsec_gss-integrity-code.patch
knfsd-nfsd-mark-rqstp-to-prevent-use-of-sendfile-in-privacy-case.patch
knfsd-svcrpc-gss-server-side-implementation-of-rpcsec_gss-privacy.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
