target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT

Make sure all non-READ SCSI commands get targ_xfer_tag initialized
to 0xffffffff, not just WRITEs.

Double-free of a TUR cmd object occurs under the following scenario:

1. TUR received (targ_xfer_tag is uninitialized and left at 0)
2. TUR status sent
3. First unsolicited NOPIN is sent to initiator (gets targ_xfer_tag of 0)
4. NOPOUT for NOPIN (with TTT=0) arrives
 - its ExpStatSN acks TUR status, TUR is queued for removal
 - LIO tries to find NOPIN with TTT=0, but finds the same TUR instead,
   TUR is queued for removal for the 2nd time

(Drop unbalanced conditional bracket usage - nab)

Signed-off-by: Alexei Potashnik <alexei@purestorage.com>
Signed-off-by: Spencer Baugh <sbaugh@catern.com>
Cc: <stable@vger.kernel.org> # v3.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index cd77a064c772f1bbe897482d2372fe5bc6434328..fd092909a4577a7c4a708516bf3344fee331ad84 100644 (file)
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -968,9 +968,9 @@ int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
                cmd->cmd_flags |= ICF_NON_IMMEDIATE_UNSOLICITED_DATA;
 
        conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
-       if (hdr->flags & ISCSI_FLAG_CMD_READ) {
+       if (hdr->flags & ISCSI_FLAG_CMD_READ)
                cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
-       } else if (hdr->flags & ISCSI_FLAG_CMD_WRITE)
+       else
                cmd->targ_xfer_tag = 0xFFFFFFFF;
        cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
        cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);