From: Sebastian Andrzej Siewior bigeasy@linutronix.de
[ Upstream commit 5c7aa13210c3abdd34fd421f62347665ec6eb551 ]
hsr_register_frame_out() compares new sequence_nr vs the old one recorded in hsr_node::seq_out and if the new sequence_nr is higher then it will be written to hsr_node::seq_out as the new value.
This operation isn't locked so it is possible that two frames with the same sequence number arrive (via the two slave devices) and are fed to hsr_register_frame_out() at the same time. Both will pass the check and update the sequence counter later to the same value. As a result the content of the same packet is fed into the stack twice.
This was noticed by running ping and observing DUP being reported from time to time.
Instead of using the hsr_priv::seqnr_lock for the whole receive path (as it is for sending in the master node) add an additional lock that is only used for sequence number checks and updates.
Add a per-node lock that is used during sequence number reads and updates.
Fixes: f421436a591d3 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Signed-off-by: Sebastian Andrzej Siewior bigeasy@linutronix.de Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/hsr/hsr_framereg.c | 9 ++++++++- net/hsr/hsr_framereg.h | 2 ++ 2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c index 805f974923b9..20cb6b7dbc69 100644 --- a/net/hsr/hsr_framereg.c +++ b/net/hsr/hsr_framereg.c @@ -159,6 +159,7 @@ static struct hsr_node *hsr_add_node(struct hsr_priv *hsr, return NULL;
ether_addr_copy(new_node->macaddress_A, addr); + spin_lock_init(&new_node->seq_out_lock);
/* We are only interested in time diffs here, so use current jiffies * as initialization. (0 could trigger an spurious ring error warning). @@ -311,6 +312,7 @@ void hsr_handle_sup_frame(struct hsr_frame_info *frame) goto done;
ether_addr_copy(node_real->macaddress_B, ethhdr->h_source); + spin_lock_bh(&node_real->seq_out_lock); for (i = 0; i < HSR_PT_PORTS; i++) { if (!node_curr->time_in_stale[i] && time_after(node_curr->time_in[i], node_real->time_in[i])) { @@ -321,6 +323,7 @@ void hsr_handle_sup_frame(struct hsr_frame_info *frame) if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i])) node_real->seq_out[i] = node_curr->seq_out[i]; } + spin_unlock_bh(&node_real->seq_out_lock); node_real->addr_B_port = port_rcv->type;
spin_lock_bh(&hsr->list_lock); @@ -413,13 +416,17 @@ void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port, int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node, u16 sequence_nr) { + spin_lock_bh(&node->seq_out_lock); if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) && time_is_after_jiffies(node->time_out[port->type] + - msecs_to_jiffies(HSR_ENTRY_FORGET_TIME))) + msecs_to_jiffies(HSR_ENTRY_FORGET_TIME))) { + spin_unlock_bh(&node->seq_out_lock); return 1; + }
node->time_out[port->type] = jiffies; node->seq_out[port->type] = sequence_nr; + spin_unlock_bh(&node->seq_out_lock); return 0; }
diff --git a/net/hsr/hsr_framereg.h b/net/hsr/hsr_framereg.h index d9628e7a5f05..5a771cb3f032 100644 --- a/net/hsr/hsr_framereg.h +++ b/net/hsr/hsr_framereg.h @@ -69,6 +69,8 @@ void prp_update_san_info(struct hsr_node *node, bool is_sup);
struct hsr_node { struct list_head mac_list; + /* Protect R/W access to seq_out */ + spinlock_t seq_out_lock; unsigned char macaddress_A[ETH_ALEN]; unsigned char macaddress_B[ETH_ALEN]; /* Local slave through which AddrB frames are received from this node */