38 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			38 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From: Felix Fietkau <nbd@nbd.name>
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Date: Wed, 15 Feb 2023 15:21:37 +0100
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Subject: [PATCH] wifi: mac80211: fix race in mesh sequence number
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 assignment
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Since the sequence number is shared across different tx queues, it needs
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to be atomic in order to avoid accidental duplicate assignment
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Signed-off-by: Felix Fietkau <nbd@nbd.name>
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---
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--- a/net/mac80211/ieee80211_i.h
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+++ b/net/mac80211/ieee80211_i.h
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@@ -696,7 +696,7 @@ struct ieee80211_if_mesh {
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 	struct mesh_stats mshstats;
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 	struct mesh_config mshcfg;
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 	atomic_t estab_plinks;
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-	u32 mesh_seqnum;
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+	atomic_t mesh_seqnum;
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 	bool accepting_plinks;
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 	int num_gates;
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 	struct beacon_data __rcu *beacon;
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--- a/net/mac80211/mesh.c
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+++ b/net/mac80211/mesh.c
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@@ -752,10 +752,8 @@ unsigned int ieee80211_new_mesh_header(s
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 	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
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-	/* FIXME: racy -- TX on multiple queues can be concurrent */
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-	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
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-	sdata->u.mesh.mesh_seqnum++;
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-
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+	put_unaligned_le32(atomic_inc_return(&sdata->u.mesh.mesh_seqnum),
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+			   &meshhdr->seqnum);
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 	if (addr4or5 && !addr6) {
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 		meshhdr->flags |= MESH_FLAGS_AE_A4;
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 		memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);
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