6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Stefan Haberland <sth@xxxxxxxxxxxxx>
commit b3a58f3b90f564f42a5c35778d8c5107b2c2150b upstream.
Fix invalid dereferencing of indirect CCW data pointer in
dasd_eckd_dump_sense() that leads to a kernel panic in error cases.
When using indirect addressing for DASD CCWs (IDAW) the CCW CDA pointer
does not contain the data address itself but a pointer to the IDAL.
This needs to be translated from physical to virtual as well before
using it.
This dereferencing is also used for dasd_page_cache and also fixed
although it is very unlikely that this code path ever gets used.
Fixes: c0bd39601c13 ("s390/dasd: use new address translation helpers")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Stefan Haberland <sth@xxxxxxxxxxxxx>
Reviewed-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/s390/block/dasd_eckd.c | 4 ++--
drivers/s390/block/dasd_fba.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 2f16f543079b..a76c6af9ea63 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -4906,7 +4906,7 @@ dasd_eckd_free_cp(struct dasd_ccw_req *cqr, struct request *req)
ccw++;
if (dst) {
if (ccw->flags & CCW_FLAG_IDA)
- cda = *((char **)dma32_to_virt(ccw->cda));
+ cda = dma64_to_virt(*((dma64_t *)dma32_to_virt(ccw->cda)));
else
cda = dma32_to_virt(ccw->cda);
if (dst != cda) {
@@ -5525,7 +5525,7 @@ dasd_eckd_dump_ccw_range(struct dasd_device *device, struct ccw1 *from,
/* get pointer to data (consider IDALs) */
if (from->flags & CCW_FLAG_IDA)
- datap = (char *)*((addr_t *)dma32_to_virt(from->cda));
+ datap = dma64_to_virt(*((dma64_t *)dma32_to_virt(from->cda)));
else
datap = dma32_to_virt(from->cda);
diff --git a/drivers/s390/block/dasd_fba.c b/drivers/s390/block/dasd_fba.c
index 361e9bd75257..9f2023a077c2 100644
--- a/drivers/s390/block/dasd_fba.c
+++ b/drivers/s390/block/dasd_fba.c
@@ -585,7 +585,7 @@ dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req)
ccw++;
if (dst) {
if (ccw->flags & CCW_FLAG_IDA)
- cda = *((char **)dma32_to_virt(ccw->cda));
+ cda = dma64_to_virt(*((dma64_t *)dma32_to_virt(ccw->cda)));
else
cda = dma32_to_virt(ccw->cda);
if (dst != cda) {
--
2.45.2
