After commit 6d684e54690c ("rhashtable: Cap total number of
entries to 2^31"), we would be hitting a panic() in net/core/rtnetlink.c
during initialization. The call stack would look like this:
register_pernet_subsys()
...
ops->init()
rtnetlink_net_init()
netlink_kernel_create()
netlink_insert()
__netlink_insert()
rhashtable_lookup_insert_key()
__rhashtable_insert_fast()
rht_grow_above_max()
And here, we have rht_grow_above_max() return true, because ht->nelemts = 0
(legit)
&& ht->max_elems = 0 (looks bogus).
Eventually, we would be return -E2BIG from __rhashtable_insert_fast()
and propagate this all the way back to the caller.
After commit 6d684e54690c what changed is that we would take the
following condition:
if (ht->p.max_size < ht->max_elems / 2)
ht->max_elems = ht->p.max_size * 2;
and since ht->p.max_size = 0, we would set ht->max_elems to 0 as well.
Fix this by taking this branch only when ht->p.max_size is non-zero
Fixes: Fixes: 6d684e54690c ("rhashtable: Cap total number of entries to 2^31")
Signed-off-by: Florian Fainelli <florian.faine...@broadcom.com>
---
lib/rhashtable.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 751630bbe409..6b4f07760fec 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -963,7 +963,7 @@ int rhashtable_init(struct rhashtable *ht,
/* Cap total entries at 2^31 to avoid nelems overflow. */
ht->max_elems = 1u << 31;
- if (ht->p.max_size < ht->max_elems / 2)
+ if (ht->p.max_size && (ht->p.max_size < ht->max_elems / 2))
ht->max_elems = ht->p.max_size * 2;
ht->p.min_size = max(ht->p.min_size, HASH_MIN_SIZE);
--
2.12.2
