| Message ID | 20250109123532.41768-2-pablo@netfilter.org (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [nf] netfilter: conntrack: clamp maximum hashtable size to INT_MAX | expand |
On Thu, Jan 09, 2025 at 01:35:30PM +0100, Pablo Neira Ayuso wrote: > According to 0708a0afe291 ("mm: Consider __GFP_NOWARN flag for oversized > kvmalloc() calls"), use INT_MAX as maximum size for the conntrack > hashtable. Otherwise, it is possible to hit WARN_ON_ONCE in > __kvmalloc_node_noprof() when __GFP_NOWARN flag is unset when resizing. > > Note: hashtable resize is only possible from init_netns. Please, ignore this duplicated patch with incorrect [nf] tag that slipped through this submission. Sorry for the inconvenience. Thanks.
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 8666d733b984..7f8b245e287a 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -2510,12 +2510,15 @@ void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls) struct hlist_nulls_head *hash; unsigned int nr_slots, i; - if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head))) + if (*sizep > (INT_MAX / sizeof(struct hlist_nulls_head))) return NULL; BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head)); nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head)); + if (nr_slots > (INT_MAX / sizeof(struct hlist_nulls_head))) + return NULL; + hash = kvcalloc(nr_slots, sizeof(struct hlist_nulls_head), GFP_KERNEL); if (hash && nulls)
According to 0708a0afe291 ("mm: Consider __GFP_NOWARN flag for oversized kvmalloc() calls"), use INT_MAX as maximum size for the conntrack hashtable. Otherwise, it is possible to hit WARN_ON_ONCE in __kvmalloc_node_noprof() when __GFP_NOWARN flag is unset when resizing. Note: hashtable resize is only possible from init_netns. Fixes: 9cc1c73ad666 ("netfilter: conntrack: avoid integer overflow when resizing") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/netfilter/nf_conntrack_core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)