On 2021/10/11 23:29, Mike Christie wrote:
On 10/11/21 1:35 AM, Ulrich Windl wrote:
Joe Perches <joe@xxxxxxxxxxx> schrieb am 09.10.2021 um 05:14 in Nachricht
<5daf69b365e23ceecee911c4d0f2f66a0b9ec95c.camel@xxxxxxxxxxx>:
On Sat, 2021-10-09 at 11:02 +0800, Guo Zhi wrote:
Pointers should be printed with %p or %px rather than
cast to (unsigned long long) and printed with %llu.
Change %llu to %p to print the pointer into sysfs.
][]
diff --git a/drivers/scsi/scsi_transport_iscsi.c
b/drivers/scsi/scsi_transport_iscsi.c
[]
@@ -129,8 +129,8 @@ show_transport_handle(struct device *dev, struct
device_attribute *attr,
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- return sysfs_emit(buf, "%llu\n",
- (unsigned long long)iscsi_handle(priv->iscsi_transport));
+ return sysfs_emit(buf, "%p\n",
+ iscsi_ptr(priv->iscsi_transport));
iscsi_transport is a pointer isn't it?
so why not just
return sysfs_emit(buf, "%p\n", priv->iscsi_transport);
Isn't the difference that %p outputs hex, while %u outputs decimal?
Yeah, I think this patch will break userspace, because it doesn't know it's
a pointer. It could be doing:
sscanf(str, "%llu", &val);
The value is just later passed back to the kernel to look up a driver in
iscsi_if_transport_lookup:
list_for_each_entry(priv, &iscsi_transports, list) {
if (tt == priv->iscsi_transport) {
so we could just replace priv->transport with an int and use an ida to assign
the value.
Taking security into consideration, We should not print kernel pointer
into sysfs.
However if this is a special pointer to lookup a driver, It's really
tricky for me to fix it,
as I don't have a scsi device to test my code.
Guo
