Re: Patch "bonding: return -ENOMEM instead of BUG in alb_upper_dev_walk" has been added to the 6.7-stable tree

[shaozhengchao <shaozhengchao@xxxxxxxxxx>]

Hi Sasha:
  This patch needs to be merged, and following log print repair patch
needs to be merged together. And the same to other stable branches.
Thank you.

commit 486058f42a4728053ae69ebbf78e9731d8ce6f8b
Author: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
Date:   Thu Nov 23 09:55:15 2023 +0800

    bonding: remove print in bond_verify_device_path

    As suggested by Paolo in link[1], if the memory allocation fails, 
the mm
    layer will emit a lot warning comprising the backtrace, so remove the
    print.

    [1] 
https://lore.kernel.org/all/20231118081653.1481260-1-shaozhengchao@xxxxxxxxxx/

    Suggested-by: Paolo Abeni <pabeni@xxxxxxxxxx>
    Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
    Reviewed-by: Hangbin Liu <liuhangbin@xxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>

diff --git a/drivers/net/bonding/bond_main.c 
b/drivers/net/bonding/bond_main.c
index d987432cee3b..4e0600c7b050 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2973,11 +2973,8 @@ struct bond_vlan_tag 
*bond_verify_device_path(struct net_device *start_dev,

        if (start_dev == end_dev) {
                tags = kcalloc(level + 1, sizeof(*tags), GFP_ATOMIC);
-               if (!tags) {
-                       net_err_ratelimited("%s: %s: Failed to allocate 
tags\n",
-                                           __func__, start_dev->name);
+               if (!tags)
                        return ERR_PTR(-ENOMEM);
-               }
                tags[level].vlan_proto = BOND_VLAN_PROTO_NONE;
                return tags;
        }

Zhengchao Shao

On 2024/2/2 0:59, Sasha Levin wrote:
> This is a note to let you know that I've just added the patch titled
>
>      bonding: return -ENOMEM instead of BUG in alb_upper_dev_walk
>
> to the 6.7-stable tree which can be found at:
>      http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>
> The filename of the patch is:
>       bonding-return-enomem-instead-of-bug-in-alb_upper_de.patch
> and it can be found in the queue-6.7 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@xxxxxxxxxxxxxxx> know about it.
>
>
>
> commit 3222d33507b127b2e5aa39dff365089b315c03fc
> Author: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
> Date:   Sat Nov 18 16:16:53 2023 +0800
>
>      bonding: return -ENOMEM instead of BUG in alb_upper_dev_walk
>      
>      [ Upstream commit d6b83f1e3707c4d60acfa58afd3515e17e5d5384 ]
>      
>      If failed to allocate "tags" or could not find the final upper device from
>      start_dev's upper list in bond_verify_device_path(), only the loopback
>      detection of the current upper device should be affected, and the system is
>      no need to be panic.
>      So return -ENOMEM in alb_upper_dev_walk to stop walking, print some warn
>      information when failed to allocate memory for vlan tags in
>      bond_verify_device_path.
>      
>      I also think that the following function calls
>      netdev_walk_all_upper_dev_rcu
>      ---->>>alb_upper_dev_walk
>      ---------->>>bond_verify_device_path
>      From this way, "end device" can eventually be obtained from "start device"
>      in bond_verify_device_path, IS_ERR(tags) could be instead of
>      IS_ERR_OR_NULL(tags) in alb_upper_dev_walk.
>      
>      Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
>      Acked-by: Jay Vosburgh <jay.vosburgh@xxxxxxxxxxxxx>
>      Link: https://lore.kernel.org/r/20231118081653.1481260-1-shaozhengchao@xxxxxxxxxx
>      Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
>      Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
>
> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
> index dc2c7b979656..7edf0fd58c34 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -985,7 +985,8 @@ static int alb_upper_dev_walk(struct net_device *upper,
>   	if (netif_is_macvlan(upper) && !strict_match) {
>   		tags = bond_verify_device_path(bond->dev, upper, 0);
>   		if (IS_ERR_OR_NULL(tags))
> -			BUG();
> +			return -ENOMEM;
> +
>   		alb_send_lp_vid(slave, upper->dev_addr,
>   				tags[0].vlan_proto, tags[0].vlan_id);
>   		kfree(tags);
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 8e6cc0e133b7..9c1652886f4e 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -2973,8 +2973,11 @@ struct bond_vlan_tag *bond_verify_device_path(struct net_device *start_dev,
>   
>   	if (start_dev == end_dev) {
>   		tags = kcalloc(level + 1, sizeof(*tags), GFP_ATOMIC);
> -		if (!tags)
> +		if (!tags) {
> +			net_err_ratelimited("%s: %s: Failed to allocate tags\n",
> +					    __func__, start_dev->name);
>   			return ERR_PTR(-ENOMEM);
> +		}
>   		tags[level].vlan_proto = BOND_VLAN_PROTO_NONE;
>   		return tags;
>   	}