[PATCH net-next] net: bridge: Allow base 16 inputs in sysfs

[PATCH net-next] net: bridge: Allow base 16 inputs in sysfs

[Ido Schimmel]

From: Ido Schimmel <idosch@nvidia.com>

Cited commit converted simple_strtoul() to kstrtoul() as suggested by
the former's documentation. However, it also forced all the inputs to be
decimal resulting in user space breakage.

Fix by setting the base to '0' so that the base is automatically
detected.

Before:

 # ip link add name br0 type bridge vlan_filtering 1
 # echo "0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
 bash: echo: write error: Invalid argument

After:

 # ip link add name br0 type bridge vlan_filtering 1
 # echo "0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
 # echo $?
 0

Fixes: 520fbdf7fb19 ("net/bridge: replace simple_strtoul to kstrtol")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 net/bridge/br_sysfs_br.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
index 11c490694296..159590d5c2af 100644
--- a/net/bridge/br_sysfs_br.c
+++ b/net/bridge/br_sysfs_br.c
@@ -41,7 +41,7 @@ static ssize_t store_bridge_parm(struct device *d,
 	if (!ns_capable(dev_net(br->dev)->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
 
-	err = kstrtoul(buf, 10, &val);
+	err = kstrtoul(buf, 0, &val);
 	if (err != 0)
 		return err;
 
-- 
2.31.1

Re: [PATCH net-next] net: bridge: Allow base 16 inputs in sysfs

[Nikolay Aleksandrov]

On 24/11/2021 12:11, Ido Schimmel wrote:
> From: Ido Schimmel <idosch@nvidia.com>
> 
> Cited commit converted simple_strtoul() to kstrtoul() as suggested by
> the former's documentation. However, it also forced all the inputs to be
> decimal resulting in user space breakage.
> 
> Fix by setting the base to '0' so that the base is automatically
> detected.
> 
> Before:
> 
>  # ip link add name br0 type bridge vlan_filtering 1
>  # echo "0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
>  bash: echo: write error: Invalid argument
> 
> After:
> 
>  # ip link add name br0 type bridge vlan_filtering 1
>  # echo "0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
>  # echo $?
>  0
> 
> Fixes: 520fbdf7fb19 ("net/bridge: replace simple_strtoul to kstrtol")
> Signed-off-by: Ido Schimmel <idosch@nvidia.com>
> ---

Thank you for taking care of this.
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>

>  net/bridge/br_sysfs_br.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c
> index 11c490694296..159590d5c2af 100644
> --- a/net/bridge/br_sysfs_br.c
> +++ b/net/bridge/br_sysfs_br.c
> @@ -41,7 +41,7 @@ static ssize_t store_bridge_parm(struct device *d,
>  	if (!ns_capable(dev_net(br->dev)->user_ns, CAP_NET_ADMIN))
>  		return -EPERM;
>  
> -	err = kstrtoul(buf, 10, &val);
> +	err = kstrtoul(buf, 0, &val);
>  	if (err != 0)
>  		return err;
>  
> 

RE: [PATCH net-next] net: bridge: Allow base 16 inputs in sysfs

[David Laight]

From: Ido Schimmel
> Sent: 24 November 2021 10:11
>
> Cited commit converted simple_strtoul() to kstrtoul() as suggested by
> the former's documentation. However, it also forced all the inputs to be
> decimal resulting in user space breakage.
> 
> Fix by setting the base to '0' so that the base is automatically
> detected.

Do both functions ignore leading whitespace?

I recently had to fix some code that did:
	if (write(sys_class_led_fd, on ? "255" : "  0", 3) != 3)
		return error.
I'm pretty sure I'd tested it before and it worked ok.
But I had to use "000" with a later kernel.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH net-next] net: bridge: Allow base 16 inputs in sysfs

[Ido Schimmel]

On Wed, Nov 24, 2021 at 12:55:33PM +0000, David Laight wrote:
> From: Ido Schimmel
> > Sent: 24 November 2021 10:11
> >
> > Cited commit converted simple_strtoul() to kstrtoul() as suggested by
> > the former's documentation. However, it also forced all the inputs to be
> > decimal resulting in user space breakage.
> > 
> > Fix by setting the base to '0' so that the base is automatically
> > detected.
> 
> Do both functions ignore leading whitespace?

With this patch (kstrtoul):

# ip link add name br0 type bridge vlan_filtering 1
# echo "    0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
bash: echo: write error: Invalid argument

With simple_strtoul:

# ip link add name br0 type bridge vlan_filtering 1
# echo "    0x88a8" > /sys/class/net/br0/bridge/vlan_protocol
bash: echo: write error: Invalid argument

Re: [PATCH net-next] net: bridge: Allow base 16 inputs in sysfs

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Wed, 24 Nov 2021 12:11:22 +0200 you wrote:
> From: Ido Schimmel <idosch@nvidia.com>
> 
> Cited commit converted simple_strtoul() to kstrtoul() as suggested by
> the former's documentation. However, it also forced all the inputs to be
> decimal resulting in user space breakage.
> 
> Fix by setting the base to '0' so that the base is automatically
> detected.
> 
> [...]

Here is the summary with links:
  - [net-next] net: bridge: Allow base 16 inputs in sysfs
    https://git.kernel.org/netdev/net-next/c/5a45ab3f248b

You are awesome, thank you!
-- 
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