Commit 9547308b authored Jul 21, 2015 by Alexei Potashnik Committed by Nicholas Bellinger Jul 30, 2015

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>

parent 94509182

drivers/target/iscsi/iscsi_target.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);