On Mar 11, 2014, at 17:27, Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> wrote: > > On Mar 11, 2014, at 17:11, Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> wrote: > >> If the i_security field isn't set then security_dentry_init_security() >> won't initialize some of the values used by the security label. This >> causes my client to hit a BUG_ON() while encoding a label of size >> -2128927414. >> >> I hit this bug while testing on a client without SELinux installed. >> >> Signed-off-by: Anna Schumaker <anna.schumaker@xxxxxxxxxx> >> --- >> fs/nfs/nfs4proc.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c >> index b8cd560..994ccc2 100644 >> --- a/fs/nfs/nfs4proc.c >> +++ b/fs/nfs/nfs4proc.c >> @@ -105,6 +105,9 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry, >> if (nfs_server_capable(dir, NFS_CAP_SECURITY_LABEL) == 0) >> return NULL; >> >> + if (!dir->i_security) >> + return NULL; >> + >> err = security_dentry_init_security(dentry, sattr->ia_mode, >> &dentry->d_name, (void **)&label->label, &label->len); >> if (err == 0) > > Hi Anna, > > This looks like a check that needs to be done by selinux_dentry_init_security() itself. The dir->i_security field is not something that NFS knows about. > David, what needs to happen there when dentry->d_parent->i_security (a.k.a. dsec) is NULL? > Oh, wait. I missed the bit about ‘without SELinux installed’. So the problem here is that you have a NFS client that does not have SELinux set up, but running against a server that is advertising NFSv4.2 with labeled NFS. Is that correct? It looks to me as if cap_dentry_init_security() will indeed trigger this behaviour since it returns ‘0’ without doing anything to the label. As far as I can see, the right thing to do there is to return -EOPNOTSUPP, no? _________________________________ Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@xxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
