Patch "bonding: return -ENOMEM instead of BUG in alb_upper_dev_walk" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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 6.1-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-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 1868c13636a3566cd9042c0fc4ec70538f58fcee
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 fc5da5d7744d..9c4c2c7d90ef 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 710734a5af9b..2b333a62ba81 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2943,8 +2943,11 @@ 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 = VLAN_N_VID;
 		return tags;
 	}