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authorJuhee Kang2022-02-19 15:29:59 +0000
committerDavid S. Miller2022-02-19 16:39:45 +0000
commite7f27420681f23e7e0f28beed38144058752112e (patch)
tree0b3788376ed56e8a2f4a64bc77ad24187df0ba8f
parent92c54a65e6a82a897a9fecaae8de6c57682ba510 (diff)
net: hsr: fix suspicious RCU usage warning in hsr_node_get_first()
When hsr_create_self_node() calls hsr_node_get_first(), the suspicious RCU usage warning is occurred. The reason why this warning is raised is the callers of hsr_node_get_first() use rcu_read_lock_bh() and other different synchronization mechanisms. Thus, this patch solved by replacing rcu_dereference() with rcu_dereference_bh_check(). The kernel test robot reports: [ 50.083470][ T3596] ============================= [ 50.088648][ T3596] WARNING: suspicious RCU usage [ 50.093785][ T3596] 5.17.0-rc3-next-20220208-syzkaller #0 Not tainted [ 50.100669][ T3596] ----------------------------- [ 50.105513][ T3596] net/hsr/hsr_framereg.c:34 suspicious rcu_dereference_check() usage! [ 50.113799][ T3596] [ 50.113799][ T3596] other info that might help us debug this: [ 50.113799][ T3596] [ 50.124257][ T3596] [ 50.124257][ T3596] rcu_scheduler_active = 2, debug_locks = 1 [ 50.132368][ T3596] 2 locks held by syz-executor.0/3596: [ 50.137863][ T3596] #0: ffffffff8d3357e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3be/0xb80 [ 50.147470][ T3596] #1: ffff88807ec9d5f0 (&hsr->list_lock){+...}-{2:2}, at: hsr_create_self_node+0x225/0x650 [ 50.157623][ T3596] [ 50.157623][ T3596] stack backtrace: [ 50.163510][ T3596] CPU: 1 PID: 3596 Comm: syz-executor.0 Not tainted 5.17.0-rc3-next-20220208-syzkaller #0 [ 50.173381][ T3596] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.183623][ T3596] Call Trace: [ 50.186904][ T3596] <TASK> [ 50.189844][ T3596] dump_stack_lvl+0xcd/0x134 [ 50.194640][ T3596] hsr_node_get_first+0x9b/0xb0 [ 50.199499][ T3596] hsr_create_self_node+0x22d/0x650 [ 50.204688][ T3596] hsr_dev_finalize+0x2c1/0x7d0 [ 50.209669][ T3596] hsr_newlink+0x315/0x730 [ 50.214113][ T3596] ? hsr_dellink+0x130/0x130 [ 50.218789][ T3596] ? rtnl_create_link+0x7e8/0xc00 [ 50.223803][ T3596] ? hsr_dellink+0x130/0x130 [ 50.228397][ T3596] __rtnl_newlink+0x107c/0x1760 [ 50.233249][ T3596] ? rtnl_setlink+0x3c0/0x3c0 [ 50.238043][ T3596] ? is_bpf_text_address+0x77/0x170 [ 50.243362][ T3596] ? lock_downgrade+0x6e0/0x6e0 [ 50.248219][ T3596] ? unwind_next_frame+0xee1/0x1ce0 [ 50.253605][ T3596] ? entry_SYSCALL_64_after_hwframe+0x44/0xae [ 50.259669][ T3596] ? __sanitizer_cov_trace_cmp4+0x1c/0x70 [ 50.265423][ T3596] ? is_bpf_text_address+0x99/0x170 [ 50.270819][ T3596] ? kernel_text_address+0x39/0x80 [ 50.275950][ T3596] ? __kernel_text_address+0x9/0x30 [ 50.281336][ T3596] ? unwind_get_return_address+0x51/0x90 [ 50.286975][ T3596] ? create_prof_cpu_mask+0x20/0x20 [ 50.292178][ T3596] ? arch_stack_walk+0x93/0xe0 [ 50.297172][ T3596] ? kmem_cache_alloc_trace+0x42/0x2c0 [ 50.302637][ T3596] ? rcu_read_lock_sched_held+0x3a/0x70 [ 50.308194][ T3596] rtnl_newlink+0x64/0xa0 [ 50.312524][ T3596] ? __rtnl_newlink+0x1760/0x1760 [ 50.317545][ T3596] rtnetlink_rcv_msg+0x413/0xb80 [ 50.322631][ T3596] ? rtnl_newlink+0xa0/0xa0 [ 50.327159][ T3596] netlink_rcv_skb+0x153/0x420 [ 50.331931][ T3596] ? rtnl_newlink+0xa0/0xa0 [ 50.336436][ T3596] ? netlink_ack+0xa80/0xa80 [ 50.341095][ T3596] ? netlink_deliver_tap+0x1a2/0xc40 [ 50.346532][ T3596] ? netlink_deliver_tap+0x1b1/0xc40 [ 50.351839][ T3596] netlink_unicast+0x539/0x7e0 [ 50.356633][ T3596] ? netlink_attachskb+0x880/0x880 [ 50.361750][ T3596] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 50.368003][ T3596] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 50.374707][ T3596] ? __phys_addr_symbol+0x2c/0x70 [ 50.379753][ T3596] ? __sanitizer_cov_trace_cmp8+0x1d/0x70 [ 50.385568][ T3596] ? __check_object_size+0x16c/0x4f0 [ 50.390859][ T3596] netlink_sendmsg+0x904/0xe00 [ 50.395715][ T3596] ? netlink_unicast+0x7e0/0x7e0 [ 50.400722][ T3596] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 50.407003][ T3596] ? netlink_unicast+0x7e0/0x7e0 [ 50.412119][ T3596] sock_sendmsg+0xcf/0x120 [ 50.416548][ T3596] __sys_sendto+0x21c/0x320 [ 50.421052][ T3596] ? __ia32_sys_getpeername+0xb0/0xb0 [ 50.426427][ T3596] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 50.432721][ T3596] ? __context_tracking_exit+0xb8/0xe0 [ 50.438188][ T3596] ? lock_downgrade+0x6e0/0x6e0 [ 50.443041][ T3596] ? lock_downgrade+0x6e0/0x6e0 [ 50.447902][ T3596] __x64_sys_sendto+0xdd/0x1b0 [ 50.452759][ T3596] ? lockdep_hardirqs_on+0x79/0x100 [ 50.457964][ T3596] ? syscall_enter_from_user_mode+0x21/0x70 [ 50.464150][ T3596] do_syscall_64+0x35/0xb0 [ 50.468565][ T3596] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 50.474452][ T3596] RIP: 0033:0x7f3148504e1c [ 50.479052][ T3596] Code: fa fa ff ff 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 20 fb ff ff 48 8b [ 50.498926][ T3596] RSP: 002b:00007ffeab5f2ab0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [ 50.507342][ T3596] RAX: ffffffffffffffda RBX: 00007f314959d320 RCX: 00007f3148504e1c [ 50.515393][ T3596] RDX: 0000000000000048 RSI: 00007f314959d370 RDI: 0000000000000003 [ 50.523444][ T3596] RBP: 0000000000000000 R08: 00007ffeab5f2b04 R09: 000000000000000c [ 50.531492][ T3596] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 [ 50.539455][ T3596] R13: 00007f314959d370 R14: 0000000000000003 R15: 0000000000000000 Fixes: 4acc45db7115 ("net: hsr: use hlist_head instead of list_head for mac addresses") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Reported-and-tested-by: syzbot+f0eb4f3876de066b128c@syzkaller.appspotmail.com Signed-off-by: Juhee Kang <claudiajkang@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/hsr/hsr_framereg.c16
-rw-r--r--net/hsr/hsr_framereg.h2
2 files changed, 11 insertions, 7 deletions
diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c
index b3c6ffa1894d..62272d76545c 100644
--- a/net/hsr/hsr_framereg.c
+++ b/net/hsr/hsr_framereg.c
@@ -27,11 +27,11 @@ u32 hsr_mac_hash(struct hsr_priv *hsr, const unsigned char *addr)
return reciprocal_scale(hash, hsr->hash_buckets);
}
-struct hsr_node *hsr_node_get_first(struct hlist_head *head)
+struct hsr_node *hsr_node_get_first(struct hlist_head *head, int cond)
{
struct hlist_node *first;
- first = rcu_dereference(hlist_first_rcu(head));
+ first = rcu_dereference_bh_check(hlist_first_rcu(head), cond);
if (first)
return hlist_entry(first, struct hsr_node, mac_list);
@@ -59,7 +59,8 @@ bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
{
struct hsr_node *node;
- node = hsr_node_get_first(&hsr->self_node_db);
+ node = hsr_node_get_first(&hsr->self_node_db,
+ lockdep_is_held(&hsr->list_lock));
if (!node) {
WARN_ONCE(1, "HSR: No self node\n");
return false;
@@ -106,7 +107,8 @@ int hsr_create_self_node(struct hsr_priv *hsr,
ether_addr_copy(node->macaddress_B, addr_b);
spin_lock_bh(&hsr->list_lock);
- oldnode = hsr_node_get_first(self_node_db);
+ oldnode = hsr_node_get_first(self_node_db,
+ lockdep_is_held(&hsr->list_lock));
if (oldnode) {
hlist_replace_rcu(&oldnode->mac_list, &node->mac_list);
spin_unlock_bh(&hsr->list_lock);
@@ -125,7 +127,8 @@ void hsr_del_self_node(struct hsr_priv *hsr)
struct hsr_node *node;
spin_lock_bh(&hsr->list_lock);
- node = hsr_node_get_first(self_node_db);
+ node = hsr_node_get_first(self_node_db,
+ lockdep_is_held(&hsr->list_lock));
if (node) {
hlist_del_rcu(&node->mac_list);
kfree_rcu(node, rcu_head);
@@ -597,7 +600,8 @@ void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
hash = hsr_mac_hash(hsr, addr);
if (!_pos) {
- node = hsr_node_get_first(&hsr->node_db[hash]);
+ node = hsr_node_get_first(&hsr->node_db[hash],
+ lockdep_is_held(&hsr->list_lock));
if (node)
ether_addr_copy(addr, node->macaddress_A);
return node;
diff --git a/net/hsr/hsr_framereg.h b/net/hsr/hsr_framereg.h
index d7cce6b161e3..2efd03fb3465 100644
--- a/net/hsr/hsr_framereg.h
+++ b/net/hsr/hsr_framereg.h
@@ -29,7 +29,7 @@ struct hsr_frame_info {
};
u32 hsr_mac_hash(struct hsr_priv *hsr, const unsigned char *addr);
-struct hsr_node *hsr_node_get_first(struct hlist_head *head);
+struct hsr_node *hsr_node_get_first(struct hlist_head *head, int cond);
void hsr_del_self_node(struct hsr_priv *hsr);
void hsr_del_nodes(struct hlist_head *node_db);
struct hsr_node *hsr_get_node(struct hsr_port *port, struct hlist_head *node_db,