[PATCH v1 net 2/4] neighbour: Enforce min/max to NDTPA_INTERVAL_PROBE_TIME_MS.

[Kuniyuki Iwashima <kuniyu@google.com>]

NDTPA_INTERVAL_PROBE_TIME_MS sets .type and .min but misses
.validation_type, so no validation is applied:

  # ynl --family rt-neigh --do setneightbl \
  --json '{"name": "arp_cache", "parms": {"interval-probe-time-ms": 0}}'

  # ynl --family rt-neigh --dump getneightbl --output-json | \
  jq '.[] | select(.name == "arp_cache" and has("config"))
          | .parms["interval-probe-time-ms"]'
  0

Moreover, nla_get_msecs() uses msecs_to_jiffies(), and u64 is
silently cast to u32, so a larger value can bypass the min check:

  e.g. 4294967296 == 0x100000000

  # ynl --family rt-neigh --do setneightbl \
  --json '{"name": "arp_cache", "parms": {"interval-probe-time-ms": 4294967296}}'

  # ynl --family rt-neigh --dump getneightbl --output-json | \
  jq '.[] | select(.name == "arp_cache" and has("config"))
          | .parms["interval-probe-time-ms"]'
  0

msecs_to_jiffies() returns MAX_JIFFY_OFFSET if the value is
larger than INT_MAX.  Also, INT_MAX ms overflows int NEIGH_VAR()
when HZ > 1000 (Alpha, MIPS), and passing a negative integer to
queue_delayed_work(unsigned long delay) causes sign extension,
which wraps around the expiry time to the past, resulting in it
being handled as 0 delay in the timer wheel.

Let's use NLA_POLICY_FULL_RANGE() and limit the max to 1 day.

The same max check is applied to sysctl as well.

Fixes: 211da42eaa45 ("net, neigh: introduce interval_probe_time_ms for periodic probe")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
Currently, the sysctl range check is not applied to
interval_probe_time_ms, which needs this fix:
https://lore.kernel.org/linux-fsdevel/20260905233819.1064529-2-kuniyu@google.com/

Cc: Yuwei Wang <wangyuweihx@gmail.com>
---
 net/core/neighbour.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 4b17c2a15594..454a8b8f3aa0 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2359,6 +2359,13 @@ static const struct nla_policy nl_neightbl_policy[NDTA_MAX+1] = {
 	[NDTA_PARMS]		= { .type = NLA_NESTED },
 };
 
+#define NTBL_PARM_MS_MAX	(24 * 60 * 60 * MSEC_PER_SEC)
+
+static const struct netlink_range_validation nl_ntbl_parm_ms_range = {
+	.min = 1,
+	.max = NTBL_PARM_MS_MAX,
+};
+
 static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
 	[NDTPA_IFINDEX]			= { .type = NLA_U32 },
 	[NDTPA_QUEUE_LEN]		= { .type = NLA_U32 },
@@ -2375,7 +2382,8 @@ static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
 	[NDTPA_ANYCAST_DELAY]		= { .type = NLA_U64 },
 	[NDTPA_PROXY_DELAY]		= { .type = NLA_U64 },
 	[NDTPA_LOCKTIME]		= { .type = NLA_U64 },
-	[NDTPA_INTERVAL_PROBE_TIME_MS]	= { .type = NLA_U64, .min = 1 },
+	[NDTPA_INTERVAL_PROBE_TIME_MS]	= NLA_POLICY_FULL_RANGE(NLA_U64,
+								&nl_ntbl_parm_ms_range),
 };
 
 static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh,
@@ -3670,12 +3678,13 @@ static int neigh_proc_dointvec_ms_jiffies_positive(const struct ctl_table *ctl,
 						   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table tmp = *ctl;
-	int ret;
+	int ret, min, max;
 
-	int min = msecs_to_jiffies(1);
+	min = msecs_to_jiffies(1);
+	max = msecs_to_jiffies(NTBL_PARM_MS_MAX);
 
 	tmp.extra1 = &min;
-	tmp.extra2 = NULL;
+	tmp.extra2 = &max;
 
 	ret = proc_dointvec_ms_jiffies_minmax(&tmp, write, buffer, lenp, ppos);
 	neigh_proc_update(ctl, write);
-- 
2.55.0.1003.g10538fe699-goog