[PATCH AUTOSEL 4.14 1/4] wifi: mac80211: don't return unset power in ieee80211_get_tx_power()

[PATCH AUTOSEL 4.14 1/4] wifi: mac80211: don't return unset power in ieee80211_get_tx_power()

[Sasha Levin]

From: Ping-Ke Shih <pkshih@realtek.com>

[ Upstream commit e160ab85166e77347d0cbe5149045cb25e83937f ]

We can get a UBSAN warning if ieee80211_get_tx_power() returns the
INT_MIN value mac80211 internally uses for "unset power level".

 UBSAN: signed-integer-overflow in net/wireless/nl80211.c:3816:5
 -2147483648 * 100 cannot be represented in type 'int'
 CPU: 0 PID: 20433 Comm: insmod Tainted: G        WC OE
 Call Trace:
  dump_stack+0x74/0x92
  ubsan_epilogue+0x9/0x50
  handle_overflow+0x8d/0xd0
  __ubsan_handle_mul_overflow+0xe/0x10
  nl80211_send_iface+0x688/0x6b0 [cfg80211]
  [...]
  cfg80211_register_wdev+0x78/0xb0 [cfg80211]
  cfg80211_netdev_notifier_call+0x200/0x620 [cfg80211]
  [...]
  ieee80211_if_add+0x60e/0x8f0 [mac80211]
  ieee80211_register_hw+0xda5/0x1170 [mac80211]

In this case, simply return an error instead, to indicate
that no data is available.

Cc: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://lore.kernel.org/r/20230203023636.4418-1-pkshih@realtek.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mac80211/cfg.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 94293b57f1b23..05e74004376fb 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2428,6 +2428,10 @@ static int ieee80211_get_tx_power(struct wiphy *wiphy,
 	else
 		*dbm = sdata->vif.bss_conf.txpower;
 
+	/* INT_MIN indicates no power level was set yet */
+	if (*dbm == INT_MIN)
+		return -EINVAL;
+
 	return 0;
 }
 
-- 
2.42.0

[PATCH AUTOSEL 4.14 4/4] net: annotate data-races around sk->sk_dst_pending_confirm

[Sasha Levin]

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit eb44ad4e635132754bfbcb18103f1dcb7058aedd ]

This field can be read or written without socket lock being held.

Add annotations to avoid load-store tearing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/net/sock.h    | 6 +++---
 net/core/sock.c       | 2 +-
 net/ipv4/tcp_output.c | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 7b42ddca4decb..f974b548e1199 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1804,7 +1804,7 @@ static inline void dst_negative_advice(struct sock *sk)
 		if (ndst != dst) {
 			rcu_assign_pointer(sk->sk_dst_cache, ndst);
 			sk_tx_queue_clear(sk);
-			sk->sk_dst_pending_confirm = 0;
+			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
 		}
 	}
 }
@@ -1815,7 +1815,7 @@ __sk_dst_set(struct sock *sk, struct dst_entry *dst)
 	struct dst_entry *old_dst;
 
 	sk_tx_queue_clear(sk);
-	sk->sk_dst_pending_confirm = 0;
+	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
 	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
 					    lockdep_sock_is_held(sk));
 	rcu_assign_pointer(sk->sk_dst_cache, dst);
@@ -1828,7 +1828,7 @@ sk_dst_set(struct sock *sk, struct dst_entry *dst)
 	struct dst_entry *old_dst;
 
 	sk_tx_queue_clear(sk);
-	sk->sk_dst_pending_confirm = 0;
+	WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
 	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
 	dst_release(old_dst);
 }
diff --git a/net/core/sock.c b/net/core/sock.c
index 5b9f51a27dc0d..e8b5742d91492 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -534,7 +534,7 @@ struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
 
 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
 		sk_tx_queue_clear(sk);
-		sk->sk_dst_pending_confirm = 0;
+		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
 		dst_release(dst);
 		return NULL;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8b2d49120ce23..67636017f275a 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1059,7 +1059,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 	skb_set_hash_from_sk(skb, sk);
 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
 
-	skb_set_dst_pending_confirm(skb, sk->sk_dst_pending_confirm);
+	skb_set_dst_pending_confirm(skb, READ_ONCE(sk->sk_dst_pending_confirm));
 
 	/* Build TCP header and checksum it. */
 	th = (struct tcphdr *)skb->data;
-- 
2.42.0