]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
libceph: validate con->state at the top of try_write()
authorIlya Dryomov <idryomov@gmail.com>
Tue, 24 Apr 2018 17:10:55 +0000 (19:10 +0200)
committerIlya Dryomov <idryomov@gmail.com>
Thu, 26 Apr 2018 15:39:08 +0000 (17:39 +0200)
commit9c55ad1c214d9f8c4594ac2c3fa392c1c32431a7
tree1520b5b53003aa6bfee5e8afc255cd73061ffc2d
parent7b4c443d139f1d2b5570da475f7a9cbcef86740c
libceph: validate con->state at the top of try_write()

ceph_con_workfn() validates con->state before calling try_read() and
then try_write().  However, try_read() temporarily releases con->mutex,
notably in process_message() and ceph_con_in_msg_alloc(), opening the
window for ceph_con_close() to sneak in, close the connection and
release con->sock.  When try_write() is called on the assumption that
con->state is still valid (i.e. not STANDBY or CLOSED), a NULL sock
gets passed to the networking stack:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
  IP: selinux_socket_sendmsg+0x5/0x20

Make sure con->state is valid at the top of try_write() and add an
explicit BUG_ON for this, similar to try_read().

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/23706
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>
net/ceph/messenger.c