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author | Elena Reshetova <elena.reshetova@intel.com> | 2017-10-20 12:53:38 +0300 |
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committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2017-11-17 13:48:01 -0500 |
commit | 212bf41d88c06afc23e03f9b274eebf1e8dba197 (patch) | |
tree | 755a58e9b423e6e8bfe06fa2036b633a427ff42b /net | |
parent | 2f62b5aa4814be2c511553fd6afb4d35b6c2503b (diff) | |
download | linux-stable-212bf41d88c06afc23e03f9b274eebf1e8dba197.tar.gz linux-stable-212bf41d88c06afc23e03f9b274eebf1e8dba197.tar.bz2 linux-stable-212bf41d88c06afc23e03f9b274eebf1e8dba197.zip |
fs, nfs: convert nfs_client.cl_count 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 nfs_client.cl_count 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: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net')
0 files changed, 0 insertions, 0 deletions