linux/drivers/s390
Elena Reshetova ae6959273a qeth: convert qeth_reply.refcnt from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable qeth_reply.refcnt is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
[jwi: removed the WARN_ONs. Use CONFIG_REFCOUNT_FULL if you care.]
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-20 15:23:44 -05:00
..
block s390: add a few more SPDX identifiers 2017-12-05 07:51:09 +01:00
char s390: add a few more SPDX identifiers 2017-12-05 07:51:09 +01:00
cio s390: add a few more SPDX identifiers 2017-12-05 07:51:09 +01:00
crypto s390: crypto: Remove redundant license text 2017-11-24 14:28:46 +01:00
net qeth: convert qeth_reply.refcnt from atomic_t to refcount_t 2017-12-20 15:23:44 -05:00
scsi s390: add a few more SPDX identifiers 2017-12-05 07:51:09 +01:00
virtio s390: drivers: Remove redundant license text 2017-11-24 14:28:47 +01:00
Makefile s390: add a few more SPDX identifiers 2017-12-05 07:51:09 +01:00