knfsd: only set ATTR_KILL_S*ID if ATTR_MODE isn't being explicitly set
It's theoretically possible for a single SETATTR call to come in that sets the
mode and the uid/gid. In that case, don't set the ATTR_KILL_S*ID bits since
that would trip the BUG() in notify_change. Just fix up the mode to have the
same effect.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 819545d..46934c9 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -364,14 +364,23 @@
if (iap->ia_valid & ATTR_MODE) {
iap->ia_mode &= S_IALLUGO;
imode = iap->ia_mode |= (imode & ~S_IALLUGO);
+ /* if changing uid/gid revoke setuid/setgid in mode */
+ if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) {
+ iap->ia_valid |= ATTR_KILL_PRIV;
+ iap->ia_mode &= ~S_ISUID;
+ }
+ if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
+ iap->ia_mode &= ~S_ISGID;
+ } else {
+ /*
+ * 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;
}
- /* 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;