]> git.baikalelectronics.ru Git - kernel.git/commit
drivers, net: convert masces_tx_sa.refcnt from atomic_t to refcount_t
authorElena Reshetova <elena.reshetova@intel.com>
Fri, 20 Oct 2017 07:23:45 +0000 (10:23 +0300)
committerDavid S. Miller <davem@davemloft.net>
Sun, 22 Oct 2017 01:22:39 +0000 (02:22 +0100)
commit1a1a4d9188a7b507325b9e747ad7439012bd60be
treeccfef81625bbe98a5632d1ef314b7deb7f9185bb
parent6b66e26055945da748840b58261ba7da72e8173e
drivers, net: convert masces_tx_sa.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 masces_tx_sa.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>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/macsec.c