From f667de2e66ea9b8f99353ff01221bb355faf3f3c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 29 Nov 2011 20:05:55 +0000 Subject: ipv4: fix lockdep splat in rt_cache_seq_show [ Upstream commit 218fa90f072e4aeff9003d57e390857f4f35513e ] After commit f2c31e32b378 (fix NULL dereferences in check_peer_redir()), dst_get_neighbour() should be guarded by rcu_read_lock() / rcu_read_unlock() section. Reported-by: Miles Lane Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/route.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 075212e41b8..8b3661b3cda 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -417,9 +417,13 @@ static int rt_cache_seq_show(struct seq_file *seq, void *v) else { struct rtable *r = v; struct neighbour *n; - int len; + int len, HHUptod; + rcu_read_lock(); n = dst_get_neighbour(&r->dst); + HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0; + rcu_read_unlock(); + seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t" "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n", r->dst.dev ? r->dst.dev->name : "*", @@ -433,7 +437,7 @@ static int rt_cache_seq_show(struct seq_file *seq, void *v) dst_metric(&r->dst, RTAX_RTTVAR)), r->rt_key_tos, -1, - (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0, + HHUptod, r->rt_spec_dst, &len); seq_printf(seq, "%*s\n", 127 - len, ""); -- cgit v1.2.3