[PATCH 2/7] knfsd: only set ATTR_KILL_S*ID if ATTR_MODE isn't being explicitly set

From: Jeff Layton
Date: Mon Sep 10 2007 - 10:53:49 EST


It's theoretically possible for a single SETATTR call to come in that
sets the mode and the uid/gid. In that case, assume the mode is
correct and don't set the ATTR_KILL_S*ID bits. Doing so would trip the
BUG() in notify_change.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/nfsd/vfs.c | 17 +++++++++++------
1 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 70f2c86..3b5b8cf 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -369,14 +369,19 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
if (iap->ia_valid & ATTR_MODE) {
iap->ia_mode &= S_IALLUGO;
imode = iap->ia_mode |= (imode & ~S_IALLUGO);
+ if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid)
+ iap->ia_valid |= ATTR_KILL_PRIV;
+ } else {
+ /*
+ * Revoke setuid/setgid bit on chown/chgrp, unless the mode
+ * is being explicitly set
+ */
+ if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid)
+ iap->ia_valid |= ATTR_KILL_SUID | ATTR_KILL_PRIV;
+ if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
+ iap->ia_valid |= ATTR_KILL_SGID;
}

- /* Revoke setuid/setgid bit on chown/chgrp */
- if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid)
- iap->ia_valid |= ATTR_KILL_SUID | ATTR_KILL_PRIV;
- if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
- iap->ia_valid |= ATTR_KILL_SGID;
-
/* Change the attributes. */

iap->ia_valid |= ATTR_CTIME;
--
1.5.2.1

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