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net: hsr: remove seqnr_lock

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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: 06afd2c31d ("hsr: Synchronize sending frames to have always incremented outgoing seq nr.")
Fixes: f421436a59 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2024-09-04 13:37:25 +00:00 committed by David S. Miller
parent d759ee240d
commit b3c9e65eb2
4 changed files with 14 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
net/hsr/hsr_device.c
View File

@ -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);

4
net/hsr/hsr_forward.c
View File

@ -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);
}
}

6
net/hsr/hsr_main.h
View File

@ -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

2
net/hsr/hsr_netlink.c
View File

@ -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;