diff mbox series

[v4,net,05/12] ipv4: use RCU protection in rt_is_expired()

Message ID 20250205155120.1676781-6-edumazet@google.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series net: first round to use dev_net_rcu() | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: dsahern@kernel.org
netdev/build_clang success Errors and warnings before: 2 this patch: 2
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 14 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet Feb. 5, 2025, 3:51 p.m. UTC 
rt_is_expired() must use RCU protection to make
sure the net structure it reads does not disappear.

Fixes: e84f84f27647 ("netns: place rt_genid into struct net")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/ipv4/route.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 74c074f45758be5ae78a87edb31837481cc40278..e959327c0ba8979ce5c7ca8c46ae41068824edc6 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -390,7 +390,13 @@  static inline int ip_rt_proc_init(void)
 
 static inline bool rt_is_expired(const struct rtable *rth)
 {
-	return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
+	bool res;
+
+	rcu_read_lock();
+	res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev));
+	rcu_read_unlock();
+
+	return res;
 }
 
 void rt_cache_flush(struct net *net)