[PATCH net 0/2] net: bridge: br_get_linkxstats_size() fixes

STALE1777d

6 messages, 3 authors, 2021-10-05 · open the first message on its own page

[PATCH net 0/2] net: bridge: br_get_linkxstats_size() fixes

From: Eric Dumazet <hidden>
Date: 2021-10-05 01:05:16

From: Eric Dumazet <edumazet@google.com>

This patch series attempts to fix the following syzbot report.

WARNING: CPU: 1 PID: 21425 at net/core/rtnetlink.c:5388 rtnl_stats_get+0x80f/0x8c0 net/core/rtnetlink.c:5388
Modules linked in:
CPU: 1 PID: 21425 Comm: syz-executor394 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:rtnl_stats_get+0x80f/0x8c0 net/core/rtnetlink.c:5388
Code: e9 9c fc ff ff 4c 89 e7 89 0c 24 e8 ab 8b a8 fa 8b 0c 24 e9 bc fc ff ff 4c 89 e7 e8 9b 8b a8 fa e9 df fe ff ff e8 61 85 63 fa <0f> 0b e9 f7 fc ff ff 41 be ea ff ff ff e9 f9 fc ff ff 41 be 97 ff
RSP: 0018:ffffc9000cf77688 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 000000000000012c RCX: 0000000000000000
RDX: ffff8880211754c0 RSI: ffffffff8711571f RDI: 0000000000000003
RBP: ffff8880175aa780 R08: 00000000ffffffa6 R09: ffff88823bd5c04f
R10: ffffffff87115413 R11: 0000000000000001 R12: ffff8880175aab74
R13: ffff8880175aab40 R14: 00000000ffffffa6 R15: 0000000000000006
FS:  0000000001ff9300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005cfd58 CR3: 000000002cd43000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5562
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4440d9

Eric Dumazet (2):
  net: bridge: use nla_total_size_64bit() in br_get_linkxstats_size()
  net: bridge: fix under estimation in br_get_linkxstats_size()

 net/bridge/br_netlink.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

-- 
2.33.0.800.g4c38ced690-goog

[PATCH net 1/2] net: bridge: use nla_total_size_64bit() in br_get_linkxstats_size()

From: Eric Dumazet <hidden>
Date: 2021-10-05 01:05:17

From: Eric Dumazet <edumazet@google.com>

bridge_fill_linkxstats() is using nla_reserve_64bit().

We must use nla_total_size_64bit() instead of nla_total_size()
for corresponding data structure.

Fixes: 1080ab95e3c7 ("net: bridge: add support for IGMP/MLD stats and export them via netlink")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nikolay Aleksandrov <redacted>
Cc: Vivien Didelot <redacted>
---
 net/bridge/br_netlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 6c58fc14d2cb2de8bcd8364fc5e766247aba2e97..29b8f6373fb925d48ce876dcda7fccc10539240a 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c

@@ -1666,7 +1666,7 @@ static size_t br_get_linkxstats_size(const struct net_device *dev, int attr)
 	}
 
 	return numvls * nla_total_size(sizeof(struct bridge_vlan_xstats)) +
-	       nla_total_size(sizeof(struct br_mcast_stats)) +
+	       nla_total_size_64bit(sizeof(struct br_mcast_stats)) +
 	       nla_total_size(0);
 }

-- 
2.33.0.800.g4c38ced690-goog

[PATCH net 2/2] net: bridge: fix under estimation in br_get_linkxstats_size()

From: Eric Dumazet <hidden>
Date: 2021-10-05 01:05:22

From: Eric Dumazet <edumazet@google.com>

Commit de1799667b00 ("net: bridge: add STP xstats")
added an additional nla_reserve_64bit() in br_fill_linkxstats(),
but forgot to update br_get_linkxstats_size() accordingly.

This can trigger the following in rtnl_stats_get()

	WARN_ON(err == -EMSGSIZE);

Fixes: de1799667b00 ("net: bridge: add STP xstats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vivien Didelot <redacted>
Cc: Nikolay Aleksandrov <redacted>
---
 net/bridge/br_netlink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 29b8f6373fb925d48ce876dcda7fccc10539240a..5c6c4305ed235891b2ed5c5a17eb8382f2aec1a0 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c

@@ -1667,6 +1667,7 @@ static size_t br_get_linkxstats_size(const struct net_device *dev, int attr)
 
 	return numvls * nla_total_size(sizeof(struct bridge_vlan_xstats)) +
 	       nla_total_size_64bit(sizeof(struct br_mcast_stats)) +
+	       (p ? nla_total_size_64bit(sizeof(p->stp_xstats)) : 0) +
 	       nla_total_size(0);
 }

-- 
2.33.0.800.g4c38ced690-goog

Re: [PATCH net 1/2] net: bridge: use nla_total_size_64bit() in br_get_linkxstats_size()

From: Nikolay Aleksandrov <hidden>
Date: 2021-10-05 09:03:50

On 05/10/2021 04:05, Eric Dumazet wrote:

quoted hunk

From: Eric Dumazet <edumazet@google.com>

bridge_fill_linkxstats() is using nla_reserve_64bit().

We must use nla_total_size_64bit() instead of nla_total_size()
for corresponding data structure.

Fixes: 1080ab95e3c7 ("net: bridge: add support for IGMP/MLD stats and export them via netlink")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nikolay Aleksandrov <redacted>
Cc: Vivien Didelot <redacted>
---
 net/bridge/br_netlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 6c58fc14d2cb2de8bcd8364fc5e766247aba2e97..29b8f6373fb925d48ce876dcda7fccc10539240a 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c

@@ -1666,7 +1666,7 @@ static size_t br_get_linkxstats_size(const struct net_device *dev, int attr)
 	}
 
 	return numvls * nla_total_size(sizeof(struct bridge_vlan_xstats)) +
-	       nla_total_size(sizeof(struct br_mcast_stats)) +
+	       nla_total_size_64bit(sizeof(struct br_mcast_stats)) +
 	       nla_total_size(0);
 }

Good catch. Thanks,
Acked-by: Nikolay Aleksandrov <redacted>

Re: [PATCH net 2/2] net: bridge: fix under estimation in br_get_linkxstats_size()

From: Nikolay Aleksandrov <hidden>
Date: 2021-10-05 09:04:34

On 05/10/2021 04:05, Eric Dumazet wrote:

quoted hunk

From: Eric Dumazet <edumazet@google.com>

Commit de1799667b00 ("net: bridge: add STP xstats")
added an additional nla_reserve_64bit() in br_fill_linkxstats(),
but forgot to update br_get_linkxstats_size() accordingly.

This can trigger the following in rtnl_stats_get()

	WARN_ON(err == -EMSGSIZE);

Fixes: de1799667b00 ("net: bridge: add STP xstats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vivien Didelot <redacted>
Cc: Nikolay Aleksandrov <redacted>
---
 net/bridge/br_netlink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 29b8f6373fb925d48ce876dcda7fccc10539240a..5c6c4305ed235891b2ed5c5a17eb8382f2aec1a0 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c

@@ -1667,6 +1667,7 @@ static size_t br_get_linkxstats_size(const struct net_device *dev, int attr)
 
 	return numvls * nla_total_size(sizeof(struct bridge_vlan_xstats)) +
 	       nla_total_size_64bit(sizeof(struct br_mcast_stats)) +
+	       (p ? nla_total_size_64bit(sizeof(p->stp_xstats)) : 0) +
 	       nla_total_size(0);
 }

Acked-by: Nikolay Aleksandrov <redacted>

Re: [PATCH net 0/2] net: bridge: br_get_linkxstats_size() fixes

From: patchwork-bot+netdevbpf@kernel.org
Date: 2021-10-05 11:50:15

Hello:

This series was applied to netdev/net.git (refs/heads/master):

On Mon,  4 Oct 2021 18:05:06 -0700 you wrote:

From: Eric Dumazet <edumazet@google.com>

This patch series attempts to fix the following syzbot report.

WARNING: CPU: 1 PID: 21425 at net/core/rtnetlink.c:5388 rtnl_stats_get+0x80f/0x8c0 net/core/rtnetlink.c:5388
Modules linked in:
CPU: 1 PID: 21425 Comm: syz-executor394 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:rtnl_stats_get+0x80f/0x8c0 net/core/rtnetlink.c:5388
Code: e9 9c fc ff ff 4c 89 e7 89 0c 24 e8 ab 8b a8 fa 8b 0c 24 e9 bc fc ff ff 4c 89 e7 e8 9b 8b a8 fa e9 df fe ff ff e8 61 85 63 fa <0f> 0b e9 f7 fc ff ff 41 be ea ff ff ff e9 f9 fc ff ff 41 be 97 ff
RSP: 0018:ffffc9000cf77688 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 000000000000012c RCX: 0000000000000000
RDX: ffff8880211754c0 RSI: ffffffff8711571f RDI: 0000000000000003
RBP: ffff8880175aa780 R08: 00000000ffffffa6 R09: ffff88823bd5c04f
R10: ffffffff87115413 R11: 0000000000000001 R12: ffff8880175aab74
R13: ffff8880175aab40 R14: 00000000ffffffa6 R15: 0000000000000006
FS:  0000000001ff9300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005cfd58 CR3: 000000002cd43000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5562
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4440d9

[...]

Here is the summary with links:
  - [net,1/2] net: bridge: use nla_total_size_64bit() in br_get_linkxstats_size()
    https://git.kernel.org/netdev/net/c/dbe0b8806449
  - [net,2/2] net: bridge: fix under estimation in br_get_linkxstats_size()
    https://git.kernel.org/netdev/net/c/0854a0513321

You are awesome, thank you!
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