path: root/drivers/target/iscsi/iscsi_target_erl0.h
diff options
authorNicholas Bellinger <nab@linux-iscsi.org>2017-05-24 21:47:09 -0700
committerNicholas Bellinger <nab@linux-iscsi.org>2017-05-31 15:12:31 -0700
commit25cdda95fda78d22d44157da15aa7ea34be3c804 (patch)
treefd8a89f00e89c70cb8bb4798ee3857de22221694 /drivers/target/iscsi/iscsi_target_erl0.h
parentf3cdbe39b2ab0636dec0d5d43b54f1061ce7566c (diff)
iscsi-target: Fix initial login PDU asynchronous socket close OOPs
This patch fixes a OOPs originally introduced by: commit bb048357dad6d604520c91586334c9c230366a14 Author: Nicholas Bellinger <nab@linux-iscsi.org> Date: Thu Sep 5 14:54:04 2013 -0700 iscsi-target: Add sk->sk_state_change to cleanup after TCP failure which would trigger a NULL pointer dereference when a TCP connection was closed asynchronously via iscsi_target_sk_state_change(), but only when the initial PDU processing in iscsi_target_do_login() from iscsi_np process context was blocked waiting for backend I/O to complete. To address this issue, this patch makes the following changes. First, it introduces some common helper functions used for checking socket closing state, checking login_flags, and atomically checking socket closing state + setting login_flags. Second, it introduces a LOGIN_FLAGS_INITIAL_PDU bit to know when a TCP connection has dropped via iscsi_target_sk_state_change(), but the initial PDU processing within iscsi_target_do_login() in iscsi_np context is still running. For this case, it sets LOGIN_FLAGS_CLOSED, but doesn't invoke schedule_delayed_work(). The original NULL pointer dereference case reported by MNC is now handled by iscsi_target_do_login() doing a iscsi_target_sk_check_close() before transitioning to FFP to determine when the socket has already closed, or iscsi_target_start_negotiation() if the login needs to exchange more PDUs (eg: iscsi_target_do_login returned 0) but the socket has closed. For both of these cases, the cleanup up of remaining connection resources will occur in iscsi_target_start_negotiation() from iscsi_np process context once the failure is detected. Finally, to handle to case where iscsi_target_sk_state_change() is called after the initial PDU procesing is complete, it now invokes conn->login_work -> iscsi_target_do_login_rx() to perform cleanup once existing iscsi_target_sk_check_close() checks detect connection failure. For this case, the cleanup of remaining connection resources will occur in iscsi_target_do_login_rx() from delayed workqueue process context once the failure is detected. Reported-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Mike Christie <mchristi@redhat.com> Tested-by: Mike Christie <mchristi@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Reported-by: Hannes Reinecke <hare@suse.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Sagi Grimberg <sagi@grimberg.me> Cc: Varun Prakash <varun@chelsio.com> Cc: <stable@vger.kernel.org> # v3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/iscsi/iscsi_target_erl0.h')
0 files changed, 0 insertions, 0 deletions