* [net PATCH] ipv4: drop dst in multicast routing path
@ 2022-05-05 2:00 Chris Packham
2022-05-06 3:28 ` David Ahern
2022-05-06 19:50 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Chris Packham @ 2022-05-05 2:00 UTC (permalink / raw)
To: davem, yoshfuji, dsahern, edumazet, kuba, pabeni, tgraf,
lokesh.dhoundiyal
Cc: netdev, linux-kernel, Chris Packham
From: Lokesh Dhoundiyal <lokesh.dhoundiyal@alliedtelesis.co.nz>
kmemleak reports the following when routing multicast traffic over an
ipsec tunnel.
Kmemleak output:
unreferenced object 0x8000000044bebb00 (size 256):
comm "softirq", pid 0, jiffies 4294985356 (age 126.810s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 80 00 00 00 05 13 74 80 ..............t.
80 00 00 00 04 9b bf f9 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000f83947e0>] __kmalloc+0x1e8/0x300
[<00000000b7ed8dca>] metadata_dst_alloc+0x24/0x58
[<0000000081d32c20>] __ipgre_rcv+0x100/0x2b8
[<00000000824f6cf1>] gre_rcv+0x178/0x540
[<00000000ccd4e162>] gre_rcv+0x7c/0xd8
[<00000000c024b148>] ip_protocol_deliver_rcu+0x124/0x350
[<000000006a483377>] ip_local_deliver_finish+0x54/0x68
[<00000000d9271b3a>] ip_local_deliver+0x128/0x168
[<00000000bd4968ae>] xfrm_trans_reinject+0xb8/0xf8
[<0000000071672a19>] tasklet_action_common.isra.16+0xc4/0x1b0
[<0000000062e9c336>] __do_softirq+0x1fc/0x3e0
[<00000000013d7914>] irq_exit+0xc4/0xe0
[<00000000a4d73e90>] plat_irq_dispatch+0x7c/0x108
[<000000000751eb8e>] handle_int+0x16c/0x178
[<000000001668023b>] _raw_spin_unlock_irqrestore+0x1c/0x28
The metadata dst is leaked when ip_route_input_mc() updates the dst for
the skb. Commit f38a9eb1f77b ("dst: Metadata destinations") correctly
handled dropping the dst in ip_route_input_slow() but missed the
multicast case which is handled by ip_route_input_mc(). Drop the dst in
ip_route_input_mc() avoiding the leak.
Fixes: f38a9eb1f77b ("dst: Metadata destinations")
Signed-off-by: Lokesh Dhoundiyal <lokesh.dhoundiyal@alliedtelesis.co.nz>
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
Notes:
We started seeing this leak in our scenario after commit c0d59da79534
("ip_gre: Make none-tun-dst gre tunnel store tunnel info as metadat_dst
in recv") but there may be other paths that hit the leak so I've set the
fixes tag as f38a9eb1f77b ("dst: Metadata destinations").
net/ipv4/route.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 98c6f3429593..57abd27e842c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1753,6 +1753,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
#endif
RT_CACHE_STAT_INC(in_slow_mc);
+ skb_dst_drop(skb);
skb_dst_set(skb, &rth->dst);
return 0;
}
--
2.36.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [net PATCH] ipv4: drop dst in multicast routing path
2022-05-05 2:00 [net PATCH] ipv4: drop dst in multicast routing path Chris Packham
@ 2022-05-06 3:28 ` David Ahern
2022-05-06 19:50 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: David Ahern @ 2022-05-06 3:28 UTC (permalink / raw)
To: Chris Packham, davem, yoshfuji, edumazet, kuba, pabeni, tgraf,
lokesh.dhoundiyal
Cc: netdev, linux-kernel
On 5/4/22 7:00 PM, Chris Packham wrote:
> From: Lokesh Dhoundiyal <lokesh.dhoundiyal@alliedtelesis.co.nz>
>
> kmemleak reports the following when routing multicast traffic over an
> ipsec tunnel.
>
> Kmemleak output:
> unreferenced object 0x8000000044bebb00 (size 256):
> comm "softirq", pid 0, jiffies 4294985356 (age 126.810s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 80 00 00 00 05 13 74 80 ..............t.
> 80 00 00 00 04 9b bf f9 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<00000000f83947e0>] __kmalloc+0x1e8/0x300
> [<00000000b7ed8dca>] metadata_dst_alloc+0x24/0x58
> [<0000000081d32c20>] __ipgre_rcv+0x100/0x2b8
> [<00000000824f6cf1>] gre_rcv+0x178/0x540
> [<00000000ccd4e162>] gre_rcv+0x7c/0xd8
> [<00000000c024b148>] ip_protocol_deliver_rcu+0x124/0x350
> [<000000006a483377>] ip_local_deliver_finish+0x54/0x68
> [<00000000d9271b3a>] ip_local_deliver+0x128/0x168
> [<00000000bd4968ae>] xfrm_trans_reinject+0xb8/0xf8
> [<0000000071672a19>] tasklet_action_common.isra.16+0xc4/0x1b0
> [<0000000062e9c336>] __do_softirq+0x1fc/0x3e0
> [<00000000013d7914>] irq_exit+0xc4/0xe0
> [<00000000a4d73e90>] plat_irq_dispatch+0x7c/0x108
> [<000000000751eb8e>] handle_int+0x16c/0x178
> [<000000001668023b>] _raw_spin_unlock_irqrestore+0x1c/0x28
>
> The metadata dst is leaked when ip_route_input_mc() updates the dst for
> the skb. Commit f38a9eb1f77b ("dst: Metadata destinations") correctly
> handled dropping the dst in ip_route_input_slow() but missed the
> multicast case which is handled by ip_route_input_mc(). Drop the dst in
> ip_route_input_mc() avoiding the leak.
>
> Fixes: f38a9eb1f77b ("dst: Metadata destinations")
> Signed-off-by: Lokesh Dhoundiyal <lokesh.dhoundiyal@alliedtelesis.co.nz>
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
>
> Notes:
> We started seeing this leak in our scenario after commit c0d59da79534
> ("ip_gre: Make none-tun-dst gre tunnel store tunnel info as metadat_dst
> in recv") but there may be other paths that hit the leak so I've set the
> fixes tag as f38a9eb1f77b ("dst: Metadata destinations").
>
> net/ipv4/route.c | 1 +
> 1 file changed, 1 insertion(+)
>
Reviewed-by: David Ahern <dsahern@kernel.org>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [net PATCH] ipv4: drop dst in multicast routing path
2022-05-05 2:00 [net PATCH] ipv4: drop dst in multicast routing path Chris Packham
2022-05-06 3:28 ` David Ahern
@ 2022-05-06 19:50 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-05-06 19:50 UTC (permalink / raw)
To: Chris Packham
Cc: davem, yoshfuji, dsahern, edumazet, kuba, pabeni, tgraf,
lokesh.dhoundiyal, netdev, linux-kernel
Hello:
This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:
On Thu, 5 May 2022 14:00:17 +1200 you wrote:
> From: Lokesh Dhoundiyal <lokesh.dhoundiyal@alliedtelesis.co.nz>
>
> kmemleak reports the following when routing multicast traffic over an
> ipsec tunnel.
>
> Kmemleak output:
> unreferenced object 0x8000000044bebb00 (size 256):
> comm "softirq", pid 0, jiffies 4294985356 (age 126.810s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 80 00 00 00 05 13 74 80 ..............t.
> 80 00 00 00 04 9b bf f9 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<00000000f83947e0>] __kmalloc+0x1e8/0x300
> [<00000000b7ed8dca>] metadata_dst_alloc+0x24/0x58
> [<0000000081d32c20>] __ipgre_rcv+0x100/0x2b8
> [<00000000824f6cf1>] gre_rcv+0x178/0x540
> [<00000000ccd4e162>] gre_rcv+0x7c/0xd8
> [<00000000c024b148>] ip_protocol_deliver_rcu+0x124/0x350
> [<000000006a483377>] ip_local_deliver_finish+0x54/0x68
> [<00000000d9271b3a>] ip_local_deliver+0x128/0x168
> [<00000000bd4968ae>] xfrm_trans_reinject+0xb8/0xf8
> [<0000000071672a19>] tasklet_action_common.isra.16+0xc4/0x1b0
> [<0000000062e9c336>] __do_softirq+0x1fc/0x3e0
> [<00000000013d7914>] irq_exit+0xc4/0xe0
> [<00000000a4d73e90>] plat_irq_dispatch+0x7c/0x108
> [<000000000751eb8e>] handle_int+0x16c/0x178
> [<000000001668023b>] _raw_spin_unlock_irqrestore+0x1c/0x28
>
> [...]
Here is the summary with links:
- [net] ipv4: drop dst in multicast routing path
https://git.kernel.org/netdev/net/c/9e6c6d17d1d6
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-05-06 3:28 ` David Ahern
2022-05-06 19:50 ` patchwork-bot+netdevbpf
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