Re: Possible deadlock in ipv6?
From: Eric Dumazet <hidden>
Date: 2012-06-06 15:53:47
On Wed, 2012-06-06 at 18:49 +0400, Vladimir Davydov wrote:
I'm not familiar with the linux net subsystem, so I would appreciate if
someone could clarify if the following call chain is possible:
addrconf_ifdown() calls neigh_ifdown(nd_tbl) which locks nd_tbl.lock for
writing and calls
pneigh_ifdown
pndisc_destructor
ipv6_dev_mc_dec
__ipv6_dev_mc_dec
igmp6_group_dropped
igmp6_leave_group
igmp6_send
icmp6_dst_alloc
ip6_neigh_lookup
neigh_create
and neigh_create() locks nd_tbl.lock for writing again resulting in a
deadlock.It seems a deadlock is possible indeed, good catch !