ocfs2: check if cluster name exists before deref
Commit c74a3bdd9b52 ("ocfs2: add clustername to cluster connection") is
trying to strlcpy a string which was explicitly passed as NULL in the
very same patch, triggering a NULL ptr deref.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: strlcpy (lib/string.c:388 lib/string.c:151)
CPU: 19 PID: 19426 Comm: trinity-c19 Tainted: G W 3.14.0-rc7-next-20140325-sasha-00014-g9476368-dirty #274
RIP: strlcpy (lib/string.c:388 lib/string.c:151)
Call Trace:
ocfs2_cluster_connect (fs/ocfs2/stackglue.c:350)
ocfs2_cluster_connect_agnostic (fs/ocfs2/stackglue.c:396)
user_dlm_register (fs/ocfs2/dlmfs/userdlm.c:679)
dlmfs_mkdir (fs/ocfs2/dlmfs/dlmfs.c:503)
vfs_mkdir (fs/namei.c:3467)
SyS_mkdirat (fs/namei.c:3488 fs/namei.c:3472)
tracesys (arch/x86/kernel/entry_64.S:749)
akpm: this patch probably disables the feature. A temporary thing to
avoid triviel oopses.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c
index 1324e66..ca5ce14 100644
--- a/fs/ocfs2/stackglue.c
+++ b/fs/ocfs2/stackglue.c
@@ -346,7 +346,9 @@
strlcpy(new_conn->cc_name, group, GROUP_NAME_MAX + 1);
new_conn->cc_namelen = grouplen;
- strlcpy(new_conn->cc_cluster_name, cluster_name, CLUSTER_NAME_MAX + 1);
+ if (cluster_name_len)
+ strlcpy(new_conn->cc_cluster_name, cluster_name,
+ CLUSTER_NAME_MAX + 1);
new_conn->cc_cluster_name_len = cluster_name_len;
new_conn->cc_recovery_handler = recovery_handler;
new_conn->cc_recovery_data = recovery_data;