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| author | Eric Dumazet <edumazet@google.com> | 2026-02-21 01:26:05 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-02-24 04:07:34 +0300 |
| commit | 8a8a9fac9efa6423fd74938b940cb7d731780718 (patch) | |
| tree | 4fa22788c8eb416cc14fd7c0672eef3175019b0e | |
| parent | 41e09ec73d7431dffda01b1e7208a272a5c90fb9 (diff) | |
| download | linux-8a8a9fac9efa6423fd74938b940cb7d731780718.tar.xz | |
net: do not pass flow_id to set_rps_cpu()
Blamed commit made the assumption that the RPS table for each receive
queue would have the same size, and that it would not change.
Compute flow_id in set_rps_cpu(), do not assume we can use the value
computed by get_rps_cpu(). Otherwise we risk out-of-bound access
and/or crashes.
Fixes: 48aa30443e52 ("net: Cache hash and flow_id to avoid recalculation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Krishna Kumar <krikku@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260220222605.3468081-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/core/dev.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 096b3ff13f6b..f3426385f1ba 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4992,8 +4992,7 @@ static bool rps_flow_is_active(struct rps_dev_flow *rflow, static struct rps_dev_flow * set_rps_cpu(struct net_device *dev, struct sk_buff *skb, - struct rps_dev_flow *rflow, u16 next_cpu, u32 hash, - u32 flow_id) + struct rps_dev_flow *rflow, u16 next_cpu, u32 hash) { if (next_cpu < nr_cpu_ids) { u32 head; @@ -5004,6 +5003,7 @@ set_rps_cpu(struct net_device *dev, struct sk_buff *skb, struct rps_dev_flow *tmp_rflow; unsigned int tmp_cpu; u16 rxq_index; + u32 flow_id; int rc; /* Should we steer this flow to a different hardware queue? */ @@ -5019,6 +5019,7 @@ set_rps_cpu(struct net_device *dev, struct sk_buff *skb, if (!flow_table) goto out; + flow_id = rfs_slot(hash, flow_table); tmp_rflow = &flow_table->flows[flow_id]; tmp_cpu = READ_ONCE(tmp_rflow->cpu); @@ -5066,7 +5067,6 @@ static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb, struct rps_dev_flow_table *flow_table; struct rps_map *map; int cpu = -1; - u32 flow_id; u32 tcpu; u32 hash; @@ -5113,8 +5113,7 @@ static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb, /* OK, now we know there is a match, * we can look at the local (per receive queue) flow table */ - flow_id = rfs_slot(hash, flow_table); - rflow = &flow_table->flows[flow_id]; + rflow = &flow_table->flows[rfs_slot(hash, flow_table)]; tcpu = rflow->cpu; /* @@ -5133,8 +5132,7 @@ static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb, ((int)(READ_ONCE(per_cpu(softnet_data, tcpu).input_queue_head) - rflow->last_qtail)) >= 0)) { tcpu = next_cpu; - rflow = set_rps_cpu(dev, skb, rflow, next_cpu, hash, - flow_id); + rflow = set_rps_cpu(dev, skb, rflow, next_cpu, hash); } if (tcpu < nr_cpu_ids && cpu_online(tcpu)) { |