target: Fix double-free of se_cmd in target_complete_tmr_failure
authorNicholas Bellinger <nab@linux-iscsi.org>
Fri, 26 Oct 2012 22:35:45 +0000 (15:35 -0700)
committerNicholas Bellinger <nab@linux-iscsi.org>
Fri, 26 Oct 2012 23:21:20 +0000 (16:21 -0700)
commite13d5fef88c40b87c8430f8274c3a9ca32ef90bc
tree5abcf8458b8fd80e25cbfa54776550b7d49d3f01
parentc8292d1da53fa60c7516ab03a9d83f7ea266d335
target: Fix double-free of se_cmd in target_complete_tmr_failure

Fabric drivers currently expect to internally release se_cmd in the event
of a TMR failure during target_submit_tmr(), which means the immediate call
to transport_generic_free_cmd() after TFO->queue_tm_rsp() from within
target_complete_tmr_failure() workqueue context is wrong.

This is done as some fabrics expect TMR operations to be acknowledged
before releasing the descriptor, so the assumption that core is releasing
se_cmd associated TMR memory is incorrect.  This fixes a OOPs where
transport_generic_free_cmd() was being called more than once.

This bug was originally observed with tcm_qla2xxx fabric ports.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
drivers/target/target_core_transport.c