[PATCH AUTOSEL 4.9 1/2] Bluetooth: L2CAP: Fix u8 overflow

[PATCH AUTOSEL 4.9 1/2] Bluetooth: L2CAP: Fix u8 overflow

[Sasha Levin]

From: Sungwoo Kim <iam@sung-woo.kim>

[ Upstream commit bcd70260ef56e0aee8a4fc6cd214a419900b0765 ]

By keep sending L2CAP_CONF_REQ packets, chan->num_conf_rsp increases
multiple times and eventually it will wrap around the maximum number
(i.e., 255).
This patch prevents this by adding a boundary check with
L2CAP_MAX_CONF_RSP

Btmon log:
Bluetooth monitor ver 5.64
= Note: Linux version 6.1.0-rc2 (x86_64)                               0.264594
= Note: Bluetooth subsystem version 2.22                               0.264636
@ MGMT Open: btmon (privileged) version 1.22                  {0x0001} 0.272191
= New Index: 00:00:00:00:00:00 (Primary,Virtual,hci0)          [hci0] 13.877604
@ RAW Open: 9496 (privileged) version 2.22                   {0x0002} 13.890741
= Open Index: 00:00:00:00:00:00                                [hci0] 13.900426
(...)
> ACL Data RX: Handle 200 flags 0x00 dlen 1033             #32 [hci0] 14.273106
        invalid packet size (12 != 1033)
        08 00 01 00 02 01 04 00 01 10 ff ff              ............
> ACL Data RX: Handle 200 flags 0x00 dlen 1547             #33 [hci0] 14.273561
        invalid packet size (14 != 1547)
        0a 00 01 00 04 01 06 00 40 00 00 00 00 00        ........@.....
> ACL Data RX: Handle 200 flags 0x00 dlen 2061             #34 [hci0] 14.274390
        invalid packet size (16 != 2061)
        0c 00 01 00 04 01 08 00 40 00 00 00 00 00 00 04  ........@.......
> ACL Data RX: Handle 200 flags 0x00 dlen 2061             #35 [hci0] 14.274932
        invalid packet size (16 != 2061)
        0c 00 01 00 04 01 08 00 40 00 00 00 07 00 03 00  ........@.......
= bluetoothd: Bluetooth daemon 5.43                                   14.401828
> ACL Data RX: Handle 200 flags 0x00 dlen 1033             #36 [hci0] 14.275753
        invalid packet size (12 != 1033)
        08 00 01 00 04 01 04 00 40 00 00 00              ........@...

Signed-off-by: Sungwoo Kim <iam@sung-woo.kim>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/bluetooth/l2cap_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 5e7fb30b2320..cbf0a9d5aabc 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4183,7 +4183,8 @@ static inline int l2cap_config_req(struct l2cap_conn *conn,
 
 	chan->ident = cmd->ident;
 	l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp);
-	chan->num_conf_rsp++;
+	if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP)
+		chan->num_conf_rsp++;
 
 	/* Reset config buffer. */
 	chan->conf_len = 0;
-- 
2.35.1

[PATCH AUTOSEL 4.9 2/2] net: loopback: use NET_NAME_PREDICTABLE for name_assign_type

[Sasha Levin]

From: Rasmus Villemoes <linux@rasmusvillemoes.dk>

[ Upstream commit 31d929de5a112ee1b977a89c57de74710894bbbf ]

When the name_assign_type attribute was introduced (commit
685343fc3ba6, "net: add name_assign_type netdev attribute"), the
loopback device was explicitly mentioned as one which would make use
of NET_NAME_PREDICTABLE:

    The name_assign_type attribute gives hints where the interface name of a
    given net-device comes from. These values are currently defined:
...
      NET_NAME_PREDICTABLE:
        The ifname has been assigned by the kernel in a predictable way
        that is guaranteed to avoid reuse and always be the same for a
        given device. Examples include statically created devices like
        the loopback device [...]

Switch to that so that reading /sys/class/net/lo/name_assign_type
produces something sensible instead of returning -EINVAL.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/loopback.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 1b65f0f975cf..f04f9a87840e 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -194,7 +194,7 @@ static __net_init int loopback_net_init(struct net *net)
 	int err;
 
 	err = -ENOMEM;
-	dev = alloc_netdev(0, "lo", NET_NAME_UNKNOWN, loopback_setup);
+	dev = alloc_netdev(0, "lo", NET_NAME_PREDICTABLE, loopback_setup);
 	if (!dev)
 		goto out;
 
-- 
2.35.1

Re: [PATCH AUTOSEL 4.9 2/2] net: loopback: use NET_NAME_PREDICTABLE for name_assign_type

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 1431 bytes --]

Hi!

> From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
> 
> [ Upstream commit 31d929de5a112ee1b977a89c57de74710894bbbf ]
> 
> When the name_assign_type attribute was introduced (commit
> 685343fc3ba6, "net: add name_assign_type netdev attribute"), the
> loopback device was explicitly mentioned as one which would make use
> of NET_NAME_PREDICTABLE:
> 
>     The name_assign_type attribute gives hints where the interface name of a
>     given net-device comes from. These values are currently defined:
> ...
>       NET_NAME_PREDICTABLE:
>         The ifname has been assigned by the kernel in a predictable way
>         that is guaranteed to avoid reuse and always be the same for a
>         given device. Examples include statically created devices like
>         the loopback device [...]
> 
> Switch to that so that reading /sys/class/net/lo/name_assign_type
> produces something sensible instead of returning -EINVAL.

This was already part of the previous autosel:

Date: Tue,  6 Dec 2022 04:51:42 -0500
From: Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.9 3/3] net: loopback: use NET_NAME_PREDICTABLE for name_assign_type
X-Mailer: git-send-email 2.35.1

From: Rasmus Villemoes <linux@rasmusvillemoes.dk>

[ Upstream commit 31d929de5a112ee1b977a89c57de74710894bbbf ]

Best regards,

								Pavel
-- 
People of Russia, stop Putin before his war on Ukraine escalates.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]

Re: [PATCH AUTOSEL 4.9 2/2] net: loopback: use NET_NAME_PREDICTABLE for name_assign_type

[Rasmus Villemoes]

On 15/12/2022 11.59, Pavel Machek wrote:
> Hi!
> 
>> From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
>>
>> [ Upstream commit 31d929de5a112ee1b977a89c57de74710894bbbf ]
>>
>> When the name_assign_type attribute was introduced (commit
>> 685343fc3ba6, "net: add name_assign_type netdev attribute"), the
>> loopback device was explicitly mentioned as one which would make use
>> of NET_NAME_PREDICTABLE:
>>
>>     The name_assign_type attribute gives hints where the interface name of a
>>     given net-device comes from. These values are currently defined:
>> ...
>>       NET_NAME_PREDICTABLE:
>>         The ifname has been assigned by the kernel in a predictable way
>>         that is guaranteed to avoid reuse and always be the same for a
>>         given device. Examples include statically created devices like
>>         the loopback device [...]
>>
>> Switch to that so that reading /sys/class/net/lo/name_assign_type
>> produces something sensible instead of returning -EINVAL.
> 
> This was already part of the previous autosel:

Yup, but it was punted for a week:

https://lore.kernel.org/lkml/Y5AO7TrYsdeVqyI6@sashalap/