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Message-ID: <20231222234237.44823-2-alexhenrie24@gmail.com>
Date: Fri, 22 Dec 2023 16:42:28 -0700
From: Alex Henrie <alexhenrie24@...il.com>
To: dan@...m.net,
davem@...emloft.net,
dsahern@...nel.org,
edumazet@...gle.com,
kuba@...nel.org,
pabeni@...hat.com,
bagasdotme@...il.com,
netdev@...r.kernel.org,
linux-kernel@...r.kernel.org,
regressions@...ts.linux.dev
Cc: Alex Henrie <alexhenrie24@...il.com>
Subject: [PATCH net] net: ipv6/addrconf: clamp temporary address's preferred lifetime to public address's
Fixes: 629df6701c8a ("net: ipv6/addrconf: clamp preferred_lft to the minimum required")
Reported-by: Dan Moulding <dan@...m.net>
Closes: https://lore.kernel.org/netdev/20231221231115.12402-1-dan@danm.net/
Signed-off-by: Alex Henrie <alexhenrie24@...il.com>
---
net/ipv6/addrconf.c | 36 ++++++++++++++++++++++++++----------
1 file changed, 26 insertions(+), 10 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 2692a7b24c40..37141d3417fe 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1337,7 +1337,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block)
unsigned long tmp_tstamp, age;
unsigned long regen_advance;
unsigned long now = jiffies;
- s32 cnf_temp_preferred_lft;
+ s32 cnf_temp_preferred_lft, if_public_preferred_lft;
struct inet6_ifaddr *ift;
struct ifa6_config cfg;
long max_desync_factor;
@@ -1394,11 +1394,13 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block)
}
}
+ if_public_preferred_lft = ifp->prefered_lft;
+
memset(&cfg, 0, sizeof(cfg));
cfg.valid_lft = min_t(__u32, ifp->valid_lft,
idev->cnf.temp_valid_lft + age);
cfg.preferred_lft = cnf_temp_preferred_lft + age - idev->desync_factor;
- cfg.preferred_lft = min_t(__u32, ifp->prefered_lft, cfg.preferred_lft);
+ cfg.preferred_lft = min_t(__u32, if_public_preferred_lft, cfg.preferred_lft);
cfg.preferred_lft = min_t(__u32, cfg.valid_lft, cfg.preferred_lft);
cfg.plen = ifp->prefix_len;
@@ -1414,20 +1416,34 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block)
* 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.
+ * ...
+ *
+ * When creating a temporary address, the lifetime values MUST be
+ * derived from the corresponding prefix as follows:
+ *
+ * ...
+ *
+ * * Its Preferred Lifetime is the lower of the Preferred Lifetime
+ * of the public address or TEMP_PREFERRED_LIFETIME -
+ * DESYNC_FACTOR.
+ *
+ * To comply with the RFC's requirements, clamp the preferred lifetime
+ * to a minimum of regen_advance, unless that would exceed valid_lft or
+ * ifp->prefered_lft.
*
* 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)
+ if (cfg.preferred_lft <= regen_advance + age) {
cfg.preferred_lft = regen_advance + age + 1;
- if (cfg.preferred_lft > cfg.valid_lft) {
- in6_ifa_put(ifp);
- in6_dev_put(idev);
- ret = -1;
- goto out;
+ if (cfg.preferred_lft > cfg.valid_lft ||
+ cfg.preferred_lft > if_public_preferred_lft) {
+ in6_ifa_put(ifp);
+ in6_dev_put(idev);
+ ret = -1;
+ goto out;
+ }
}
cfg.ifa_flags = IFA_F_TEMPORARY;
--
2.43.0
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