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| author | Eric Dumazet <edumazet@google.com> | 2025-02-05 15:51:15 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-03-13 12:50:43 +0100 |
| commit | ce3c6165fce0f06305c806696882a3ad4b90e33f (patch) | |
| tree | ae2d8e805b039ba3999ba5f189f5936ec0bdfb7f /net/ipv4 | |
| parent | fc07a232326a623d0be482e307c08ea7049c2846 (diff) | |
| download | linux-ce3c6165fce0f06305c806696882a3ad4b90e33f.tar.gz linux-ce3c6165fce0f06305c806696882a3ad4b90e33f.tar.bz2 linux-ce3c6165fce0f06305c806696882a3ad4b90e33f.zip | |
ipv4: use RCU protection in __ip_rt_update_pmtu()
[ Upstream commit 139512191bd06f1b496117c76372b2ce372c9a41 ]
__ip_rt_update_pmtu() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: 2fbc6e89b2f1 ("ipv4: Update exception handling for multipath routes via same device")
Fixes: 1de6b15a434c ("Namespaceify min_pmtu sysctl")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250205155120.1676781-8-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/route.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 2ae9d2855efa..a4884d434038 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1023,9 +1023,9 @@ out: kfree_skb(skb); static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) { struct dst_entry *dst = &rt->dst; - struct net *net = dev_net(dst->dev); struct fib_result res; bool lock = false; + struct net *net; u32 old_mtu; if (ip_mtu_locked(dst)) @@ -1035,6 +1035,8 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) if (old_mtu < mtu) return; + rcu_read_lock(); + net = dev_net_rcu(dst->dev); if (mtu < net->ipv4.ip_rt_min_pmtu) { lock = true; mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); @@ -1042,9 +1044,8 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) if (rt->rt_pmtu == mtu && !lock && time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) - return; + goto out; - rcu_read_lock(); if (fib_lookup(net, fl4, &res, 0) == 0) { struct fib_nh_common *nhc; @@ -1058,14 +1059,14 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, jiffies + net->ipv4.ip_rt_mtu_expires); } - rcu_read_unlock(); - return; + goto out; } #endif /* CONFIG_IP_ROUTE_MULTIPATH */ nhc = FIB_RES_NHC(res); update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, jiffies + net->ipv4.ip_rt_mtu_expires); } +out: rcu_read_unlock(); } |