| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.2 101/110] IB/cm: Fix rb-tree duplicate free and use-after-free | Date | Fri, 6 Nov 2015 11:19:48 -0800 |
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4.2-stable review patch. If anyone has any objections, please let me know.
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From: Doron Tsur <doront@mellanox.com>
commit 0ca81a2840f77855bbad1b9f172c545c4dc9e6a4 upstream.
ib_send_cm_sidr_rep could sometimes erase the node from the sidr (depending on errors in the process). Since ib_send_cm_sidr_rep is called both from cm_sidr_req_handler and cm_destroy_id, cm_id_priv could be either erased from the rb_tree twice or not erased at all. Fixing that by making sure it's erased only once before freeing cm_id_priv.
Fixes: a977049dacde ('[PATCH] IB: Add the kernel CM implementation') Signed-off-by: Doron Tsur <doront@mellanox.com> Signed-off-by: Matan Barak <matanb@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/infiniband/core/cm.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
--- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -873,6 +873,11 @@ retest: case IB_CM_SIDR_REQ_RCVD: spin_unlock_irq(&cm_id_priv->lock); cm_reject_sidr_req(cm_id_priv, IB_SIDR_REJECT); + spin_lock_irq(&cm.lock); + if (!RB_EMPTY_NODE(&cm_id_priv->sidr_id_node)) + rb_erase(&cm_id_priv->sidr_id_node, + &cm.remote_sidr_table); + spin_unlock_irq(&cm.lock); break; case IB_CM_REQ_SENT: case IB_CM_MRA_REQ_RCVD: @@ -3112,7 +3117,10 @@ int ib_send_cm_sidr_rep(struct ib_cm_id spin_unlock_irqrestore(&cm_id_priv->lock, flags); spin_lock_irqsave(&cm.lock, flags); - rb_erase(&cm_id_priv->sidr_id_node, &cm.remote_sidr_table); + if (!RB_EMPTY_NODE(&cm_id_priv->sidr_id_node)) { + rb_erase(&cm_id_priv->sidr_id_node, &cm.remote_sidr_table); + RB_CLEAR_NODE(&cm_id_priv->sidr_id_node); + } spin_unlock_irqrestore(&cm.lock, flags); return 0;
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