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author | Elena Reshetova <elena.reshetova@intel.com> | 2017-10-20 10:23:38 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-10-22 04:22:38 +0300 |
commit | 0068895ff845c38e9e2b65c002c53c623379e436 (patch) | |
tree | 7ca05c32618d53d389617dc93d90a36bcefc329b /include/linux | |
parent | ff61b5e3f041c2f1aa8d7c700af3007889973889 (diff) | |
download | linux-0068895ff845c38e9e2b65c002c53c623379e436.tar.xz |
drivers, net, mlx4: convert mlx4_qp.refcount 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 mlx4_qp.refcount 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>
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/mlx4/device.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h index daac2e3a1a58..b8e19c4d6caa 100644 --- a/include/linux/mlx4/device.h +++ b/include/linux/mlx4/device.h @@ -768,7 +768,7 @@ struct mlx4_qp { int qpn; - atomic_t refcount; + refcount_t refcount; struct completion free; u8 usage; }; |