cxlflash: Fix AFU version access/storage and add check
The AFU version is stored as a non-terminated string of bytes within
a 64-bit little-endian register. Presently the value is read directly
(no MMIO accessor) and is stored in a buffer that is not big enough
to contain a NULL terminator. Additionally the version obtained is not
evaluated against a known value to prevent usage with unsupported AFUs.
All of these deficiencies can lead to a variety of problems.
To remedy, use the correct MMIO accessor to read the version value into
a null-terminated buffer and add a check to prevent an incompatible AFU
from being used with this driver.
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index c25efc31..c1d5c88 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -1751,14 +1751,20 @@
goto err1;
}
- /* don't byte reverse on reading afu_version, else the string form */
- /* will be backwards */
- reg = afu->afu_map->global.regs.afu_version;
- memcpy(afu->version, ®, 8);
+ /* No byte reverse on reading afu_version or string will be backwards */
+ reg = readq(&afu->afu_map->global.regs.afu_version);
+ memcpy(afu->version, ®, sizeof(reg));
afu->interface_version =
readq_be(&afu->afu_map->global.regs.interface_version);
- pr_debug("%s: afu version %s, interface version 0x%llX\n",
- __func__, afu->version, afu->interface_version);
+ if ((afu->interface_version + 1) == 0) {
+ pr_err("Back level AFU, please upgrade. AFU version %s "
+ "interface version 0x%llx\n", afu->version,
+ afu->interface_version);
+ rc = -EINVAL;
+ goto err1;
+ } else
+ pr_debug("%s: afu version %s, interface version 0x%llX\n",
+ __func__, afu->version, afu->interface_version);
rc = start_afu(cfg);
if (rc) {