| From | Kamal Mostafa <> | Subject | [PATCH 3.19.y-ckt 026/102] target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT | Date | Tue, 22 Sep 2015 10:51:22 -0700 |
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3.19.8-ckt7 -stable review patch. If anyone has any objections, please let me know.
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From: Alexei Potashnik <alexei@purestorage.com>
commit 9547308bda296b6f69876c840a0291fcfbeddbb8 upstream.
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> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> [ luis: backported to 3.16: - kept brackets as they are needed in 3.16 kernel ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/target/iscsi/iscsi_target.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 4e08d63..0c508a4 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -967,7 +967,7 @@ int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd, if (cmd->targ_xfer_tag == 0xFFFFFFFF) cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++; spin_unlock_bh(&conn->sess->ttt_lock); - } 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); -- 1.9.1
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