From: Alex Henrie <alexhenrie24@gmail.com>
To: netdev@vger.kernel.org, kernel@vger.kernel.org,
regressions@lists.linux.dev, dan@danm.net, bagasdotme@gmail.com,
davem@davemloft.net, dsahern@kernel.org, edumazet@google.com,
kuba@kernel.org, linux-pabeni@redhat.com, jikos@kernel.org
Cc: Alex Henrie <alexhenrie24@gmail.com>
Subject: [PATCH] Revert "net: ipv6/addrconf: clamp preferred_lft to the minimum required"
Date: Fri, 29 Dec 2023 21:32:44 -0700 [thread overview]
Message-ID: <20231230043252.10530-1-alexhenrie24@gmail.com> (raw)
In-Reply-To: <d2f328c6-b5b4-46d0-b087-c70e2460d28a@kernel.org>
The commit had a bug and might not have been the right approach anyway.
Fixes: 629df6701c8a ("net: ipv6/addrconf: clamp preferred_lft to the minimum required")
Fixes: ec575f885e3e ("Documentation: networking: explain what happens if temp_prefered_lft is too small or too large")
Reported-by: Dan Moulding <dan@danm.net>
Closes: https://lore.kernel.org/netdev/20231221231115.12402-1-dan@danm.net/
Link: https://lore.kernel.org/netdev/CAMMLpeTdYhd=7hhPi2Y7pwdPCgnnW5JYh-bu3hSc7im39uxnEA@mail.gmail.com/
Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
---
Documentation/networking/ip-sysctl.rst | 2 +-
net/ipv6/addrconf.c | 18 +++++-------------
2 files changed, 6 insertions(+), 14 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 4dfe0d9a57bb..7afff42612e9 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -2511,7 +2511,7 @@ temp_valid_lft - INTEGER
temp_prefered_lft - INTEGER
Preferred lifetime (in seconds) for temporary addresses. If
temp_prefered_lft is less than the minimum required lifetime (typically
- 5 seconds), the preferred lifetime is the minimum required. If
+ 5 seconds), temporary addresses will not be created. If
temp_prefered_lft is greater than temp_valid_lft, the preferred lifetime
is temp_valid_lft.
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 2692a7b24c40..733ace18806c 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1407,23 +1407,15 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block)
write_unlock_bh(&idev->lock);
- /* From RFC 4941:
- *
- * A temporary address is created only if this calculated Preferred
- * Lifetime is greater than REGEN_ADVANCE time units. In
- * particular, an implementation must not create a temporary address
- * with a zero Preferred Lifetime.
- *
- * Clamp the preferred lifetime to a minimum of regen_advance, unless
- * that would exceed valid_lft.
- *
+ /* A temporary address is created only if this calculated Preferred
+ * Lifetime is greater than REGEN_ADVANCE time units. In particular,
+ * an implementation must not create a temporary address with a zero
+ * Preferred Lifetime.
* Use age calculation as in addrconf_verify to avoid unnecessary
* temporary addresses being generated.
*/
age = (now - tmp_tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
- if (cfg.preferred_lft <= regen_advance + age)
- cfg.preferred_lft = regen_advance + age + 1;
- if (cfg.preferred_lft > cfg.valid_lft) {
+ if (cfg.preferred_lft <= regen_advance + age) {
in6_ifa_put(ifp);
in6_dev_put(idev);
ret = -1;
--
2.43.0
next prev parent reply other threads:[~2023-12-30 4:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 23:10 [REGRESSION] net/ipv6/addrconf: Temporary addresses with short lifetimes generating when they shouldn't, causing applications to fail Dan Moulding
2023-12-22 23:42 ` Alex Henrie
2023-12-22 23:42 ` [PATCH net] net: ipv6/addrconf: clamp temporary address's preferred lifetime to public address's Alex Henrie
2023-12-23 15:22 ` [REGRESSION] net/ipv6/addrconf: Temporary addresses with short lifetimes generating when they shouldn't, causing applications to fail Dan Moulding
2023-12-24 0:07 ` Alex Henrie
2023-12-29 16:33 ` Dan Moulding
2023-12-29 22:52 ` David Ahern
2023-12-30 4:32 ` Alex Henrie [this message]
2023-12-30 15:43 ` [PATCH] Revert "net: ipv6/addrconf: clamp preferred_lft to the minimum required" David Ahern
2024-01-02 23:10 ` patchwork-bot+netdevbpf
2023-12-30 4:12 ` [REGRESSION] net/ipv6/addrconf: Temporary addresses with short lifetimes generating when they shouldn't, causing applications to fail Alex Henrie
2023-12-23 8:42 ` Linux regression tracking #adding (Thorsten Leemhuis)
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