]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
ocfs2: subsystem.su_mutex is required while accessing the item->ci_parent
authoralex chen <alex.chen@huawei.com>
Thu, 16 Nov 2017 01:31:48 +0000 (17:31 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 16 Nov 2017 02:21:01 +0000 (18:21 -0800)
commit853bc26a7ea39e354b9f8889ae7ad1492ffa28d2
treec0c8313b31b634c7feeb8f564510582847eb0759
parent3e4c56d41eef5595035872a2ec5a483f42e8917f
ocfs2: subsystem.su_mutex is required while accessing the item->ci_parent

The subsystem.su_mutex is required while accessing the item->ci_parent,
otherwise, NULL pointer dereference to the item->ci_parent will be
triggered in the following situation:

add node                     delete node
sys_write
 vfs_write
  configfs_write_file
   o2nm_node_store
    o2nm_node_local_write
                             do_rmdir
                              vfs_rmdir
                               configfs_rmdir
                                mutex_lock(&subsys->su_mutex);
                                unlink_obj
                                 item->ci_group = NULL;
                                 item->ci_parent = NULL;
 to_o2nm_cluster_from_node
  node->nd_item.ci_parent->ci_parent
  BUG since of NULL pointer dereference to nd_item.ci_parent

Moreover, the o2nm_cluster also should be protected by the
subsystem.su_mutex.

[alex.chen@huawei.com: v2]
Link: http://lkml.kernel.org/r/59EEAA69.9080703@huawei.com
Link: http://lkml.kernel.org/r/59E9B36A.10700@huawei.com
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ocfs2/cluster/nodemanager.c