[PATCH 5/13 net-3.1-stable] ipv4: fix lockdep splat in rt_cache_seq_show
From: David Miller <davem@davemloft.net>
Date: 2011-12-06 21:33:23
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
From: Eric Dumazet <redacted> [ 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 <redacted> Signed-off-by: Eric Dumazet <redacted> Signed-off-by: David S. Miller <davem@davemloft.net> --- net/ipv4/route.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 075212e..8b3661b 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, "");
--
1.7.7.3