strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
We expect these fields to be NUL-terminated as the property names from
which they are derived are also NUL-terminated.
Moreover, NUL-padding is not required as our destination buffers are
already NUL-allocated and any future NUL-byte assignments are redundant
(like the ones that strncpy() does).
ibmvfc_probe() ->
| struct ibmvfc_host *vhost;
| struct Scsi_Host *shost;
...
| shost = scsi_host_alloc(&driver_template, sizeof(*vhost));
... **side note: is this a bug? Looks like a type to me ^^^^^**
...
| vhost = shost_priv(shost);
... where shost_priv() is:
| static inline void *shost_priv(struct Scsi_Host *shost)
| {
| return (void *)shost->hostdata;
| }
.. and:
scsi_host_alloc() ->
| shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
And for login_info->..., NUL-padding is also not required as it is
explicitly memset to 0:
| memset(login_info, 0, sizeof(*login_info));
Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@xxxxxxxxxxxxxxx
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
Note: build-tested only.
Found with: $ rg "strncpy\("
---
drivers/scsi/ibmvscsi/ibmvfc.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index ce9eb00e2ca0..e73a39b1c832 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -1455,7 +1455,7 @@ static void ibmvfc_gather_partition_info(struct ibmvfc_host *vhost)
name = of_get_property(rootdn, "ibm,partition-name", NULL);
if (name)
- strncpy(vhost->partition_name, name, sizeof(vhost->partition_name));
+ strscpy(vhost->partition_name, name, sizeof(vhost->partition_name));
num = of_get_property(rootdn, "ibm,partition-no", NULL);
if (num)
vhost->partition_number = *num;
@@ -1498,13 +1498,15 @@ static void ibmvfc_set_login_info(struct ibmvfc_host *vhost)
login_info->async.va = cpu_to_be64(vhost->async_crq.msg_token);
login_info->async.len = cpu_to_be32(async_crq->size *
sizeof(*async_crq->msgs.async));
- strncpy(login_info->partition_name, vhost->partition_name, IBMVFC_MAX_NAME);
- strncpy(login_info->device_name,
- dev_name(&vhost->host->shost_gendev), IBMVFC_MAX_NAME);
+ strscpy(login_info->partition_name, vhost->partition_name,
+ sizeof(login_info->partition_name));
+
+ strscpy(login_info->device_name,
+ dev_name(&vhost->host->shost_gendev), sizeof(login_info->device_name));
location = of_get_property(of_node, "ibm,loc-code", NULL);
location = location ? location : dev_name(vhost->dev);
- strncpy(login_info->drc_name, location, IBMVFC_MAX_NAME);
+ strscpy(login_info->drc_name, location, sizeof(login_info->drc_name));
}
/**
---
base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa
change-id: 20231030-strncpy-drivers-scsi-ibmvscsi-ibmvfc-c-ccfce3255d58
Best regards,
--
Justin Stitt <justinstitt@xxxxxxxxxx>
