diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h index 16ff29a7bb30cf..b289bd286d77b3 100644 --- a/include/net/inet_frag.h +++ b/include/net/inet_frag.h @@ -33,6 +33,13 @@ struct inet_frag_queue { #define INETFRAGS_HASHSZ 64 +/* averaged: + * max_depth = default ipfrag_high_thresh / INETFRAGS_HASHSZ / + * rounded up (SKB_TRUELEN(0) + sizeof(struct ipq or + * struct frag_queue)) + */ +#define INETFRAGS_MAXDEPTH 128 + struct inet_frags { struct hlist_head hash[INETFRAGS_HASHSZ]; rwlock_t lock; @@ -64,6 +71,8 @@ int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f); struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, struct inet_frags *f, void *key, unsigned int hash) __releases(&f->lock); +void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q, + const char *prefix); static inline void inet_frag_put(struct inet_frag_queue *q, struct inet_frags *f) { diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index 5ff2a51b6d0c7d..210b7102cc4f76 100644 --- a/net/ipv4/inet_fragment.c +++ b/net/ipv4/inet_fragment.c @@ -21,6 +21,7 @@ #include #include +#include #include static void inet_frag_secret_rebuild(unsigned long dummy) @@ -271,6 +272,7 @@ struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, { struct inet_frag_queue *q; struct hlist_node *n; + int depth = 0; hlist_for_each_entry(q, n, &f->hash[hash], list) { if (q->net == nf && f->match(q, key)) { @@ -278,9 +280,25 @@ struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, read_unlock(&f->lock); return q; } + depth++; } read_unlock(&f->lock); - return inet_frag_create(nf, f, key); + if (depth <= INETFRAGS_MAXDEPTH) + return inet_frag_create(nf, f, key); + else + return ERR_PTR(-ENOBUFS); } EXPORT_SYMBOL(inet_frag_find); + +void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q, + const char *prefix) +{ + static const char msg[] = "inet_frag_find: Fragment hash bucket" + " list length grew over limit " __stringify(INETFRAGS_MAXDEPTH) + ". Dropping fragment.\n"; + + if (PTR_ERR(q) == -ENOBUFS) + LIMIT_NETDEBUG(KERN_WARNING "%s%s", prefix, msg); +} +EXPORT_SYMBOL(inet_frag_maybe_warn_overflow); diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index 0ad6035f63666c..da38472beb69ad 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -20,6 +20,8 @@ * Patrick McHardy : LRU queue of frag heads for evictor. */ +#define pr_fmt(fmt) "IPv4: " fmt + #include #include #include @@ -292,14 +294,12 @@ static inline struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user) hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol); q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash); - if (q == NULL) - goto out_nomem; + if (IS_ERR_OR_NULL(q)) { + inet_frag_maybe_warn_overflow(q, pr_fmt()); + return NULL; + } return container_of(q, struct ipq, q); - -out_nomem: - LIMIT_NETDEBUG(KERN_ERR "ip_frag_create: no memory left !\n"); - return NULL; } /* Is the fragment too far ahead to be part of ipq? */ diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 085727263812e7..afc7530f56c25a 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -14,6 +14,8 @@ * 2 of the License, or (at your option) any later version. */ +#define pr_fmt(fmt) "IPv6-nf: " fmt + #include #include #include @@ -176,14 +178,12 @@ fq_find(__be32 id, u32 user, struct in6_addr *src, struct in6_addr *dst) q = inet_frag_find(&nf_init_frags, &nf_frags, &arg, hash); local_bh_enable(); - if (q == NULL) - goto oom; + if (IS_ERR_OR_NULL(q)) { + inet_frag_maybe_warn_overflow(q, pr_fmt()); + return NULL; + } return container_of(q, struct nf_ct_frag6_queue, q); - -oom: - pr_debug("Can't alloc new queue\n"); - return NULL; } diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 7b954e2539d083..43f8fc9f17aef3 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -26,6 +26,9 @@ * YOSHIFUJI,H. @USAGI Always remove fragment header to * calculate ICV correctly. */ + +#define pr_fmt(fmt) "IPv6: " fmt + #include #include #include @@ -239,9 +242,10 @@ fq_find(struct net *net, __be32 id, const struct in6_addr *src, const struct in6 hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd); q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); - if (q == NULL) + if (IS_ERR_OR_NULL(q)) { + inet_frag_maybe_warn_overflow(q, pr_fmt()); return NULL; - + } return container_of(q, struct frag_queue, q); }