[GIT PULL] SCSI fixes for 3.17-rc5

James Bottomley
2014-09-19T13:56:47Z

This is a set of three fixes. One represents a nasty shared tag map
regression (another inverted condition) caused by recent SCSI MQ
patches, one is a longstanding potential buffer overrun in the iscsi
data buffer and the final one is a use after free for the rare
bidirectional commands.

The patch is available here:

git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes

The short changelog is:

Christoph Hellwig (1):
fix regression that accidentally disabled block-based tcq

Daniel Gryniewicz (1):
fix for bidi use after free

Mike Christie (1):
libiscsi: fix potential buffer overrun in __iscsi_conn_send_pdu

And the diffstat:

drivers/scsi/libiscsi.c | 10 ++++++++++
drivers/scsi/scsi_lib.c | 5 +++--
include/scsi/scsi_tcq.h | 2 +-
3 files changed, 14 insertions(+), 3 deletions(-)

With full diff below.

James

---

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index ea025e4..191b597 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -717,11 +717,21 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
return NULL;
}

+ if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
+ iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
+ return NULL;
+ }
+
task = conn->login_task;
} else {
if (session->state != ISCSI_STATE_LOGGED_IN)
return NULL;

+ if (data_size != 0) {
+ iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
+ return NULL;
+ }
+
BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d837dc1..aaea4b9 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -733,12 +733,13 @@ static bool scsi_end_request(struct request *req, int error,
} else {
unsigned long flags;

+ if (bidi_bytes)
+ scsi_release_bidi_buffers(cmd);
+
spin_lock_irqsave(q->queue_lock, flags);
blk_finish_request(req, error);
spin_unlock_irqrestore(q->queue_lock, flags);

- if (bidi_bytes)
- scsi_release_bidi_buffers(cmd);
scsi_release_buffers(cmd);
scsi_next_command(cmd);
}
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index cdcc90b..e645835 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -68,7 +68,7 @@ static inline void scsi_activate_tcq(struct scsi_device *sdev, int depth)
return;

if (!shost_use_blk_mq(sdev->host) &&
- blk_queue_tagged(sdev->request_queue))
+ !blk_queue_tagged(sdev->request_queue))
blk_queue_init_tags(sdev->request_queue, depth,
sdev->host->bqt);