From 02113a0f14e20bd8e675d7cec16db6eaaf2b2380 Mon Sep 17 00:00:00 2001 From: Elena Reshetova Date: Fri, 17 Mar 2017 14:10:28 +0200 Subject: [PATCH] libceph: convert ceph_osd.o_ref from atomic_t to refcount_t refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: Ilya Dryomov --- include/linux/ceph/osd_client.h | 3 ++- net/ceph/osd_client.c | 16 ++++++++-------- 2 files changed, 10 insertions(+), 9 deletions(-) diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h index c125b5d..d6a625e 100644 --- a/include/linux/ceph/osd_client.h +++ b/include/linux/ceph/osd_client.h @@ -5,6 +5,7 @@ #include #include #include +#include #include #include @@ -27,7 +28,7 @@ typedef void (*ceph_osdc_callback_t)(struct ceph_osd_request *); /* a given osd we're communicating with */ struct ceph_osd { - atomic_t o_ref; + refcount_t o_ref; struct ceph_osd_client *o_osdc; int o_osd; int o_incarnation; diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c index e15ea9e..b4500a8 100644 --- a/net/ceph/osd_client.c +++ b/net/ceph/osd_client.c @@ -1005,7 +1005,7 @@ static bool osd_registered(struct ceph_osd *osd) */ static void osd_init(struct ceph_osd *osd) { - atomic_set(&osd->o_ref, 1); + refcount_set(&osd->o_ref, 1); RB_CLEAR_NODE(&osd->o_node); osd->o_requests = RB_ROOT; osd->o_linger_requests = RB_ROOT; @@ -1050,9 +1050,9 @@ static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum) static struct ceph_osd *get_osd(struct ceph_osd *osd) { - if (atomic_inc_not_zero(&osd->o_ref)) { - dout("get_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref)-1, - atomic_read(&osd->o_ref)); + if (refcount_inc_not_zero(&osd->o_ref)) { + dout("get_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref)-1, + refcount_read(&osd->o_ref)); return osd; } else { dout("get_osd %p FAIL\n", osd); @@ -1062,9 +1062,9 @@ static struct ceph_osd *get_osd(struct ceph_osd *osd) static void put_osd(struct ceph_osd *osd) { - dout("put_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref), - atomic_read(&osd->o_ref) - 1); - if (atomic_dec_and_test(&osd->o_ref)) { + dout("put_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref), + refcount_read(&osd->o_ref) - 1); + if (refcount_dec_and_test(&osd->o_ref)) { osd_cleanup(osd); kfree(osd); } @@ -4126,7 +4126,7 @@ void ceph_osdc_stop(struct ceph_osd_client *osdc) close_osd(osd); } up_write(&osdc->lock); - WARN_ON(atomic_read(&osdc->homeless_osd.o_ref) != 1); + WARN_ON(refcount_read(&osdc->homeless_osd.o_ref) != 1); osd_cleanup(&osdc->homeless_osd); WARN_ON(!list_empty(&osdc->osd_lru)); -- 2.7.4