From fab0b3ce67a54f45848ee5d6023ef9a42153a2c9 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 27 Feb 2018 19:42:31 +0100 Subject: [PATCH] netfilter: x_tables: cap allocations at 512 mbyte commit 19926968ea86a286aa6fbea16ee3f2e7442f10f0 upstream. Arbitrary limit, however, this still allows huge rulesets (> 1 million rules). This helps with automated fuzzer as it prevents oom-killer invocation. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/x_tables.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index a450a1c8804b..d1d29015d91f 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -40,6 +40,7 @@ MODULE_AUTHOR("Harald Welte "); MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module"); #define XT_PCPU_BLOCK_SIZE 4096 +#define XT_MAX_TABLE_SIZE (512 * 1024 * 1024) struct compat_delta { unsigned int offset; /* offset in kernel */ @@ -1031,7 +1032,7 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size) struct xt_table_info *info = NULL; size_t sz = sizeof(*info) + size; - if (sz < sizeof(*info)) + if (sz < sizeof(*info) || sz >= XT_MAX_TABLE_SIZE) return NULL; /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ -- 2.20.1