[PATCH 6.0 103/157] inet: ping: use hlist_nulls rcu iterator during lookup

Greg Kroah-Hartman
2022-12-12T13:42:25Z

From: Florian Westphal <fw@strlen.de>

[ Upstream commit c25b7a7a565e5eeb2459b37583eea67942057511 ]

ping_lookup() does not acquire the table spinlock, so iteration should
use hlist_nulls_for_each_entry_rcu().

Spotted during code review.

Fixes: dbca1596bbb0 ("ping: convert to RCU lookups, get rid of rwlock")
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20221129140644.28525-1-fw@strlen.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.clang-format | 1 +
include/net/ping.h | 3 ---
net/ipv4/ping.c | 7 ++++++-
3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/.clang-format b/.clang-format
index 1247d54f9e49..8d01225bfcb7 100644
--- a/.clang-format
+++ b/.clang-format
@@ -535,6 +535,7 @@ ForEachMacros:
- 'perf_hpp_list__for_each_sort_list_safe'
- 'perf_pmu__for_each_hybrid_pmu'
- 'ping_portaddr_for_each_entry'
+ - 'ping_portaddr_for_each_entry_rcu'
- 'plist_for_each'
- 'plist_for_each_continue'
- 'plist_for_each_entry'
diff --git a/include/net/ping.h b/include/net/ping.h
index e4ff3911cbf5..9233ad3de0ad 100644
--- a/include/net/ping.h
+++ b/include/net/ping.h
@@ -16,9 +16,6 @@
#define PING_HTABLE_SIZE 64
#define PING_HTABLE_MASK (PING_HTABLE_SIZE-1)

-#define ping_portaddr_for_each_entry(__sk, node, list) \
- hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
-
/*
* gid_t is either uint or ushort. We want to pass it to
* proc_dointvec_minmax(), so it must not be larger than MAX_INT
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index b83c2bd9d722..3b2420829c23 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -48,6 +48,11 @@
#include <net/transp_v6.h>
#endif

+#define ping_portaddr_for_each_entry(__sk, node, list) \
+ hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
+#define ping_portaddr_for_each_entry_rcu(__sk, node, list) \
+ hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
+
struct ping_table {
struct hlist_nulls_head hash[PING_HTABLE_SIZE];
spinlock_t lock;
@@ -191,7 +196,7 @@ static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
return NULL;
}

- ping_portaddr_for_each_entry(sk, hnode, hslot) {
+ ping_portaddr_for_each_entry_rcu(sk, hnode, hslot) {
isk = inet_sk(sk);

pr_debug("iterate\n");
--
2.35.1