1. 06 Mar, 2016 2 commits
    • Nicholas Bellinger's avatar
      target: Fix race for SCF_COMPARE_AND_WRITE_POST checking · 5dd73bb3
      Nicholas Bellinger authored
      [ Upstream commit 057085e5 ]
      
      This patch addresses a race + use after free where the first
      stage of COMPARE_AND_WRITE in compare_and_write_callback()
      is rescheduled after the backend sends the secondary WRITE,
      resulting in second stage compare_and_write_post() callback
      completing in target_complete_ok_work() before the first
      can return.
      
      Because current code depends on checking se_cmd->se_cmd_flags
      after return from se_cmd->transport_complete_callback(),
      this results in first stage having SCF_COMPARE_AND_WRITE_POST
      set, which incorrectly falls through into second stage CAW
      processing code, eventually triggering a NULL pointer
      dereference due to use after free.
      
      To address this bug, pass in a new *post_ret parameter into
      se_cmd->transport_complete_callback(), and depend upon this
      value instead of ->se_cmd_flags to determine when to return
      or fall through into ->queue_status() code for CAW.
      
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      5dd73bb3
    • Nicholas Bellinger's avatar
      iscsi-target: Fix rx_login_comp hang after login failure · 4b4bc57a
      Nicholas Bellinger authored
      [ Upstream commit ca82c2bd ]
      
      This patch addresses a case where iscsi_target_do_tx_login_io()
      fails sending the last login response PDU, after the RX/TX
      threads have already been started.
      
      The case centers around iscsi_target_rx_thread() not invoking
      allow_signal(SIGINT) before the send_sig(SIGINT, ...) occurs
      from the failure path, resulting in RX thread hanging
      indefinately on iscsi_conn->rx_login_comp.
      
      Note this bug is a regression introduced by:
      
        commit e5419865
        Author: Nicholas Bellinger <nab@linux-iscsi.org>
        Date:   Wed Jul 22 23:14:19 2015 -0700
      
            iscsi-target: Fix iscsit_start_kthreads failure OOPs
      
      To address this bug, complete ->rx_login_complete for good
      measure in the failure path, and immediately return from
      RX thread context if connection state did not actually reach
      full feature phase (TARG_CONN_STATE_LOGGED_IN).
      
      Cc: Sagi Grimberg <sagig@mellanox.com>
      Cc: <stable@vger.kernel.org> # v3.10+
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      4b4bc57a
  2. 04 Mar, 2016 38 commits