Re: [PATCH] Fix Kernel Panic in bonding driver debugfs file: rlb_hash_table
From: Vishwanath Pai
Date: Wed Apr 29 2015 - 16:30:52 EST
On 04/29/2015 03:45 PM, Nikolay Aleksandrov wrote:
> On 04/29/2015 08:24 PM, Pai wrote:
>> This patch fixes a Kernel Panic in bonding driver debugfs file: rlb_hash_table.
>>
>> $> modprobe bonding mode=6
>> $> cat /sys/kernel/debug/bonding/bond0/rlb_hash_table
>>
>> This will crash the kernel. The struct alb_bond_info is initialized only when
>> the bonding interface is initialized (ip link set bond0 up) and not at the time
>> it is allocated. If we try to read the table before that, it'll result in a
>> kernel panic.
>>
>> The patch applies against both net and net-next
>>
>> Signed-off-by: Vishwanath Pai <vpai@xxxxxxxxxx>
>>
> Good catch, a few cosmetic nits below.
>
>> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>> index 089a402..806892a 100644
>> --- a/drivers/net/bonding/bond_main.c
>> +++ b/drivers/net/bonding/bond_main.c
>> @@ -4510,6 +4510,8 @@ unsigned int bond_get_num_tx_queues(void)
>> int bond_create(struct net *net, const char *name)
>> {
>> struct net_device *bond_dev;
>> + struct bonding *bond;
>> + struct alb_bond_info *bond_info;
> Please arrange these longest to shortest line, it's easier to read.
>
>> int res;
>>
>> rtnl_lock();
>> @@ -4523,6 +4525,14 @@ int bond_create(struct net *net, const char *name)
>> return -ENOMEM;
>> }
>>
>> + /*
>> + * Initialize rx_hashtbl_used_head to RLB_NULL_INDEX.
>> + * It is set to 0 by default which is wrong.
>> + */
> Multiline comment style of networking content is:
> /* text
> * text
> */
>
> See: Documentation/networking/netdev-FAQ.txt
>
> Alternatively you can create an inline with descriptive name that does the
> initialization and wouldn't need the comment. Either way's fine by me.
>
> Cheers,
> Nik
>
>> + bond = netdev_priv(bond_dev);
>> + bond_info = &(BOND_ALB_INFO(bond));
>> + bond_info->rx_hashtbl_used_head = RLB_NULL_INDEX;
>> +
>> dev_net_set(bond_dev, net);
>> bond_dev->rtnl_link_ops = &bond_link_ops;
>>
>> --
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>
David,
Since the patch has been applied already - should I send a V2 with the
suggested changes? Or submit a new patch that applies on top of the
first patch?
Thanks,
Vishwanath
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