Re: WARNING: suspicious RCU usage in fib6_info_alloc

[David Ahern]

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 ;-)

Patch is queued up; will send later today.