path: root/include/target
diff options
authorNicholas Bellinger <nab@linux-iscsi.org>2015-11-05 23:37:59 -0800
committerNicholas Bellinger <nab@linux-iscsi.org>2015-11-28 19:33:15 -0800
commit057085e522f8bf94c2e691a5b76880f68060f8ba (patch)
treed813e53ee7853a19eb2697e71bd2851b8acc5cc6 /include/target
parentca82c2bded29b38d36140bfa1e76a7bbfcade390 (diff)
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')
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;