6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit b3c9e65eb227269ed72a115ba22f4f51b4e62b4d ] syzbot found a new splat [1]. Instead of adding yet another spin_lock_bh(&hsr->seqnr_lock) / spin_unlock_bh(&hsr->seqnr_lock) pair, remove seqnr_lock and use atomic_t for hsr->sequence_nr and hsr->sup_sequence_nr. This also avoid a race in hsr_fill_info(). Also remove interlink_sequence_nr which is unused. [1] WARNING: CPU: 1 PID: 9723 at net/hsr/hsr_forward.c:602 handle_std_frame+0x247/0x2c0 net/hsr/hsr_forward.c:602 Modules linked in: CPU: 1 UID: 0 PID: 9723 Comm: syz.0.1657 Not tainted 6.11.0-rc6-syzkaller-00026-g88fac17500f4 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:handle_std_frame+0x247/0x2c0 net/hsr/hsr_forward.c:602 Code: 49 8d bd b0 01 00 00 be ff ff ff ff e8 e2 58 25 00 31 ff 89 c5 89 c6 e8 47 53 a8 f6 85 ed 0f 85 5a ff ff ff e8 fa 50 a8 f6 90 <0f> 0b 90 e9 4c ff ff ff e8 cc e7 06 f7 e9 8f fe ff ff e8 52 e8 06 RSP: 0018:ffffc90000598598 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffc90000598670 RCX: ffffffff8ae2c919 RDX: ffff888024e94880 RSI: ffffffff8ae2c926 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003 R13: ffff8880627a8cc0 R14: 0000000000000000 R15: ffff888012b03c3a FS: 0000000000000000(0000) GS:ffff88802b700000(0063) knlGS:00000000f5696b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000020010000 CR3: 00000000768b4000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> hsr_fill_frame_info+0x2c8/0x360 net/hsr/hsr_forward.c:630 fill_frame_info net/hsr/hsr_forward.c:700 [inline] hsr_forward_skb+0x7df/0x25c0 net/hsr/hsr_forward.c:715 hsr_handle_frame+0x603/0x850 net/hsr/hsr_slave.c:70 __netif_receive_skb_core.constprop.0+0xa3d/0x4330 net/core/dev.c:5555 __netif_receive_skb_list_core+0x357/0x950 net/core/dev.c:5737 __netif_receive_skb_list net/core/dev.c:5804 [inline] netif_receive_skb_list_internal+0x753/0xda0 net/core/dev.c:5896 gro_normal_list include/net/gro.h:515 [inline] gro_normal_list include/net/gro.h:511 [inline] napi_complete_done+0x23f/0x9a0 net/core/dev.c:6247 gro_cell_poll+0x162/0x210 net/core/gro_cells.c:66 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0xa92/0x1010 net/core/dev.c:6963 handle_softirqs+0x216/0x8f0 kernel/softirq.c:554 do_softirq kernel/softirq.c:455 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:442 </IRQ> <TASK> Fixes: 06afd2c31d33 ("hsr: Synchronize sending frames to have always incremented outgoing seq nr.") Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Reviewed-by: Simon Horman <horms@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/hsr/hsr_device.c | 35 ++++++++++------------------------- net/hsr/hsr_forward.c | 4 +--- net/hsr/hsr_main.h | 6 ++---- net/hsr/hsr_netlink.c | 2 +- 4 files changed, 14 insertions(+), 33 deletions(-) diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c index e4cc6b78dcfc..ac56784c327c 100644 --- a/net/hsr/hsr_device.c +++ b/net/hsr/hsr_device.c @@ -231,9 +231,7 @@ static netdev_tx_t hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev) skb->dev = master->dev; skb_reset_mac_header(skb); skb_reset_mac_len(skb); - spin_lock_bh(&hsr->seqnr_lock); hsr_forward_skb(skb, master); - spin_unlock_bh(&hsr->seqnr_lock); } else { dev_core_stats_tx_dropped_inc(dev); dev_kfree_skb_any(skb); @@ -314,14 +312,10 @@ static void send_hsr_supervision_frame(struct hsr_port *port, set_hsr_stag_HSR_ver(hsr_stag, hsr->prot_version); /* From HSRv1 on we have separate supervision sequence numbers. */ - spin_lock_bh(&hsr->seqnr_lock); - if (hsr->prot_version > 0) { - hsr_stag->sequence_nr = htons(hsr->sup_sequence_nr); - hsr->sup_sequence_nr++; - } else { - hsr_stag->sequence_nr = htons(hsr->sequence_nr); - hsr->sequence_nr++; - } + if (hsr->prot_version > 0) + hsr_stag->sequence_nr = htons(atomic_inc_return(&hsr->sup_sequence_nr)); + else + hsr_stag->sequence_nr = htons(atomic_inc_return(&hsr->sequence_nr)); hsr_stag->tlv.HSR_TLV_type = type; /* TODO: Why 12 in HSRv0? */ @@ -343,13 +337,11 @@ static void send_hsr_supervision_frame(struct hsr_port *port, ether_addr_copy(hsr_sp->macaddress_A, hsr->macaddress_redbox); } - if (skb_put_padto(skb, ETH_ZLEN)) { - spin_unlock_bh(&hsr->seqnr_lock); + if (skb_put_padto(skb, ETH_ZLEN)) return; - } hsr_forward_skb(skb, port); - spin_unlock_bh(&hsr->seqnr_lock); + return; } @@ -374,9 +366,7 @@ static void send_prp_supervision_frame(struct hsr_port *master, set_hsr_stag_HSR_ver(hsr_stag, (hsr->prot_version ? 1 : 0)); /* From HSRv1 on we have separate supervision sequence numbers. */ - spin_lock_bh(&hsr->seqnr_lock); - hsr_stag->sequence_nr = htons(hsr->sup_sequence_nr); - hsr->sup_sequence_nr++; + hsr_stag->sequence_nr = htons(atomic_inc_return(&hsr->sup_sequence_nr)); hsr_stag->tlv.HSR_TLV_type = PRP_TLV_LIFE_CHECK_DD; hsr_stag->tlv.HSR_TLV_length = sizeof(struct hsr_sup_payload); @@ -384,13 +374,10 @@ static void send_prp_supervision_frame(struct hsr_port *master, hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload)); ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr); - if (skb_put_padto(skb, ETH_ZLEN)) { - spin_unlock_bh(&hsr->seqnr_lock); + if (skb_put_padto(skb, ETH_ZLEN)) return; - } hsr_forward_skb(skb, master); - spin_unlock_bh(&hsr->seqnr_lock); } /* Announce (supervision frame) timer function @@ -621,11 +608,9 @@ int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2], if (res < 0) return res; - spin_lock_init(&hsr->seqnr_lock); /* Overflow soon to find bugs easier: */ - hsr->sequence_nr = HSR_SEQNR_START; - hsr->sup_sequence_nr = HSR_SUP_SEQNR_START; - hsr->interlink_sequence_nr = HSR_SEQNR_START; + atomic_set(&hsr->sequence_nr, HSR_SEQNR_START); + atomic_set(&hsr->sup_sequence_nr, HSR_SUP_SEQNR_START); timer_setup(&hsr->announce_timer, hsr_announce, 0); timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0); diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c index 960ef386bc3a..9254037e9436 100644 --- a/net/hsr/hsr_forward.c +++ b/net/hsr/hsr_forward.c @@ -599,9 +599,7 @@ static void handle_std_frame(struct sk_buff *skb, if (port->type == HSR_PT_MASTER || port->type == HSR_PT_INTERLINK) { /* Sequence nr for the master/interlink node */ - lockdep_assert_held(&hsr->seqnr_lock); - frame->sequence_nr = hsr->sequence_nr; - hsr->sequence_nr++; + frame->sequence_nr = atomic_inc_return(&hsr->sequence_nr); } } diff --git a/net/hsr/hsr_main.h b/net/hsr/hsr_main.h index ab1f8d35d9dc..6f7bbf01f3e4 100644 --- a/net/hsr/hsr_main.h +++ b/net/hsr/hsr_main.h @@ -202,11 +202,9 @@ struct hsr_priv { struct timer_list prune_timer; struct timer_list prune_proxy_timer; int announce_count; - u16 sequence_nr; - u16 interlink_sequence_nr; /* Interlink port seq_nr */ - u16 sup_sequence_nr; /* For HSRv1 separate seq_nr for supervision */ + atomic_t sequence_nr; + atomic_t sup_sequence_nr; /* For HSRv1 separate seq_nr for supervision */ enum hsr_version prot_version; /* Indicate if HSRv0, HSRv1 or PRPv1 */ - spinlock_t seqnr_lock; /* locking for sequence_nr */ spinlock_t list_lock; /* locking for node list */ struct hsr_proto_ops *proto_ops; #define PRP_LAN_ID 0x5 /* 0x1010 for A and 0x1011 for B. Bit 0 is set diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c index f6ff0b61e08a..8aea4ff5f49e 100644 --- a/net/hsr/hsr_netlink.c +++ b/net/hsr/hsr_netlink.c @@ -163,7 +163,7 @@ static int hsr_fill_info(struct sk_buff *skb, const struct net_device *dev) if (nla_put(skb, IFLA_HSR_SUPERVISION_ADDR, ETH_ALEN, hsr->sup_multicast_addr) || - nla_put_u16(skb, IFLA_HSR_SEQ_NR, hsr->sequence_nr)) + nla_put_u16(skb, IFLA_HSR_SEQ_NR, atomic_read(&hsr->sequence_nr))) goto nla_put_failure; if (hsr->prot_version == PRP_V1) proto = HSR_PROTOCOL_PRP; -- 2.43.0