Re: WARNING: suspicious RCU usage in fib6_info_alloc

[Eric Dumazet]

On 04/18/2018 02:04 PM, David Ahern wrote:
> On 4/18/18 3:02 PM, syzbot wrote:
>> stack backtrace:
>> CPU: 1 PID: 25 Comm: kworker/1:1 Not tainted 4.16.0+ #5
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
>> Google 01/01/2011
>> Workqueue: ipv6_addrconf addrconf_dad_work
>> Call Trace:
>> Â__dump_stack lib/dump_stack.c:77 [inline]
>> Âdump_stack+0x1b9/0x294 lib/dump_stack.c:113
>> Âlockdep_rcu_suspicious+0x14a/0x153 kernel/locking/lockdep.c:4592
>> Â___might_sleep+0x2e7/0x320 kernel/sched/core.c:6153
>> Â__might_sleep+0x95/0x190 kernel/sched/core.c:6141
>> Âslab_pre_alloc_hook mm/slab.h:421 [inline]
>> Âslab_alloc mm/slab.c:3378 [inline]
>> Âkmem_cache_alloc_trace+0x2bc/0x780 mm/slab.c:3618
>> Âkmalloc include/linux/slab.h:512 [inline]
>> Âkzalloc include/linux/slab.h:701 [inline]
>> Âfib6_info_alloc+0xbb/0x280 net/ipv6/ip6_fib.c:152
>> Âip6_route_info_create+0x7bf/0x3240 net/ipv6/route.c:2891
>> Âip6_route_add+0x23/0xb0 net/ipv6/route.c:3030
>> Âaddrconf_prefix_route.isra.47+0x4f7/0x6f0 net/ipv6/addrconf.c:2347
>> Â__ipv6_ifa_notify+0x591/0xa00 net/ipv6/addrconf.c:5620
> 
> Eric is faster than the robot ;-)

Not really ;)

> 
> Patch is queued up; will send later today.
> 

David, I simply looked at the report before allowing the bot to send it ;)

I determined the bug was added recently, and warned you about it.

Thanks !