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| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-11-06 10:37:59 +0300 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-11-29 06:33:15 +0300 |
| commit | 057085e522f8bf94c2e691a5b76880f68060f8ba (patch) | |
| tree | d813e53ee7853a19eb2697e71bd2851b8acc5cc6 /include/target | |
| parent | ca82c2bded29b38d36140bfa1e76a7bbfcade390 (diff) | |
| download | linux-057085e522f8bf94c2e691a5b76880f68060f8ba.tar.xz | |
target: Fix race for SCF_COMPARE_AND_WRITE_POST checking
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>
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'include/target')
| -rw-r--r-- | include/target/target_core_base.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 0a2c74008e53..aabf0aca0171 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -474,7 +474,7 @@ struct se_cmd { struct completion cmd_wait_comp; const struct target_core_fabric_ops *se_tfo; sense_reason_t (*execute_cmd)(struct se_cmd *); - sense_reason_t (*transport_complete_callback)(struct se_cmd *, bool); + sense_reason_t (*transport_complete_callback)(struct se_cmd *, bool, int *); void *protocol_data; unsigned char *t_task_cdb; |