From patchwork Fri Jan 4 08:18:39 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: netfilter: xt_recent: avoid high order page allocations Date: Thu, 03 Jan 2013 22:18:39 -0000 From: Eric Dumazet X-Patchwork-Id: 209378 Message-Id: <1357287519.1678.70.camel@edumazet-glaptop> To: Pablo Neira Ayuso Cc: netdev , netfilter-devel@vger.kernel.org, Miroslav Kratochvil , h.reindl@thelounge.net, Dave Jones From: Eric Dumazet xt_recent can try high order page allocations and this can fail. iptables: page allocation failure: order:9, mode:0xc0d0 It also wastes about half the allocated space because of kmalloc() power-of-two roundups and struct recent_table layout. Use vmalloc() instead to save space and be less prone to allocation errors when memory is fragmented. Reported-by: Miroslav Kratochvil Reported-by: Dave Jones Reported-by: Harald Reindl Signed-off-by: Eric Dumazet --- net/netfilter/xt_recent.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index dab053e..978efc9 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include @@ -310,6 +311,14 @@ out: return ret; } +static void recent_table_free(void *addr) +{ + if (is_vmalloc_addr(addr)) + vfree(addr); + else + kfree(addr); +} + static int recent_mt_check(const struct xt_mtchk_param *par, const struct xt_recent_mtinfo_v1 *info) { @@ -322,6 +331,7 @@ static int recent_mt_check(const struct xt_mtchk_param *par, #endif unsigned int i; int ret = -EINVAL; + size_t sz; if (unlikely(!hash_rnd_inited)) { get_random_bytes(&hash_rnd, sizeof(hash_rnd)); @@ -360,8 +370,11 @@ static int recent_mt_check(const struct xt_mtchk_param *par, goto out; } - t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size, - GFP_KERNEL); + sz = sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size; + if (sz <= PAGE_SIZE) + t = kzalloc(sz, GFP_KERNEL); + else + t = vzalloc(sz); if (t == NULL) { ret = -ENOMEM; goto out; @@ -377,14 +390,14 @@ static int recent_mt_check(const struct xt_mtchk_param *par, uid = make_kuid(&init_user_ns, ip_list_uid); gid = make_kgid(&init_user_ns, ip_list_gid); if (!uid_valid(uid) || !gid_valid(gid)) { - kfree(t); + recent_table_free(t); ret = -EINVAL; goto out; } pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent, &recent_mt_fops, t); if (pde == NULL) { - kfree(t); + recent_table_free(t); ret = -ENOMEM; goto out; } @@ -435,7 +448,7 @@ static void recent_mt_destroy(const struct xt_mtdtor_param *par) remove_proc_entry(t->name, recent_net->xt_recent); #endif recent_table_flush(t); - kfree(t); + recent_table_free(t); } mutex_unlock(&recent_mutex); }