5.3-stable patches

added patches:
	scsi-core-handle-drivers-which-set-sg_tablesize-to-zero.patch

diff --git a/queue-5.3/scsi-core-handle-drivers-which-set-sg_tablesize-to-zero.patch b/queue-5.3/scsi-core-handle-drivers-which-set-sg_tablesize-to-zero.patch
new file mode 100644 (file)
index 0000000..50aa24c
--- /dev/null
+++ b/queue-5.3/scsi-core-handle-drivers-which-set-sg_tablesize-to-zero.patch
@@ -0,0 +1,50 @@
+From 9393c8de628cf0968d81a17cc11841e42191e041 Mon Sep 17 00:00:00 2001
+From: Michael Schmitz <schmitzmic@gmail.com>
+Date: Tue, 5 Nov 2019 15:49:10 +1300
+Subject: scsi: core: Handle drivers which set sg_tablesize to zero
+
+From: Michael Schmitz <schmitzmic@gmail.com>
+
+commit 9393c8de628cf0968d81a17cc11841e42191e041 upstream.
+
+In scsi_mq_setup_tags(), cmd_size is calculated based on zero size for the
+scatter-gather list in case the low level driver uses SG_NONE in its host
+template.
+
+cmd_size is passed on to the block layer for calculation of the request
+size, and we've seen NULL pointer dereference errors from the block layer
+in drivers where SG_NONE is used and a mq IO scheduler is active,
+apparently as a consequence of this (see commit 68ab2d76e4be ("scsi:
+cxlflash: Set sg_tablesize to 1 instead of SG_NONE"), and a recent patch by
+Finn Thain converting the three m68k NFR5380 drivers to avoid setting
+SG_NONE).
+
+Try to avoid these errors by accounting for at least one sg list entry when
+calculating cmd_size, regardless of whether the low level driver set a zero
+sg_tablesize.
+
+Tested on 030 m68k with the atari_scsi driver - setting sg_tablesize to
+SG_NONE no longer results in a crash when loading this driver.
+
+CC: Finn Thain <fthain@telegraphics.com.au>
+Link: https://lore.kernel.org/r/1572922150-4358-1-git-send-email-schmitzmic@gmail.com
+Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
+Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/scsi/scsi_lib.c |    3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/drivers/scsi/scsi_lib.c
++++ b/drivers/scsi/scsi_lib.c
+@@ -1854,7 +1854,8 @@ int scsi_mq_setup_tags(struct Scsi_Host
+ {
+       unsigned int cmd_size, sgl_size;
+ 
+-      sgl_size = scsi_mq_inline_sgl_size(shost);
++      sgl_size = max_t(unsigned int, sizeof(struct scatterlist),
++                              scsi_mq_inline_sgl_size(shost));
+       cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size;
+       if (scsi_host_get_prot(shost))
+               cmd_size += sizeof(struct scsi_data_buffer) +

diff --git a/queue-5.3/series b/queue-5.3/series
new file mode 100644 (file)
index 0000000..1f4c546
--- /dev/null
+++ b/queue-5.3/series
@@ -0,0 +1 @@
+scsi-core-handle-drivers-which-set-sg_tablesize-to-zero.patch