diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-09-05 18:52:43 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-09-07 11:12:46 +0200 |
| commit | d975ab412c33ddce2c39e0e86f87085d13b1aeca (patch) | |
| tree | f3c00eec6fc0020940bef78185aa12733ca8130b /src | |
| parent | 8087280d76c31c851c85bd1d920ba92bb642ad9f (diff) | |
netlink_delinearize: Avoid potential null pointer deref
Phil Sutter says:
As netlink_get_register() may return NULL, we must not pass the returned
data unchecked to expr_set_type() as that will dereference it. Since the
parser has failed at that point anyway, by returning early we can skip
the useless statement allocation that follows in
netlink_parse_ct_stmt().
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Phil Sutter <phil@nwl.cc>
Diffstat (limited to 'src')
| -rw-r--r-- | src/netlink_delinearize.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c index 1a1cfbde..cddbfa63 100644 --- a/src/netlink_delinearize.c +++ b/src/netlink_delinearize.c @@ -428,6 +428,10 @@ static void netlink_parse_payload_stmt(struct netlink_parse_ctx *ctx, sreg = netlink_parse_register(nle, NFTNL_EXPR_PAYLOAD_SREG); val = netlink_get_register(ctx, loc, sreg); + if (val == NULL) + return netlink_error(ctx, loc, + "payload statement has no expression"); + stmt = payload_stmt_alloc(loc, expr, val); list_add_tail(&stmt->list, &ctx->rule->stmts); @@ -473,6 +477,9 @@ static void netlink_parse_hash(struct netlink_parse_ctx *ctx, sreg = netlink_parse_register(nle, NFTNL_EXPR_HASH_SREG); hexpr = netlink_get_register(ctx, loc, sreg); + if (hexpr == NULL) + return netlink_error(ctx, loc, + "hash statement has no expression"); seed = nftnl_expr_get_u32(nle, NFTNL_EXPR_HASH_SEED); mod = nftnl_expr_get_u32(nle, NFTNL_EXPR_HASH_MODULUS); @@ -517,6 +524,9 @@ static void netlink_parse_meta_stmt(struct netlink_parse_ctx *ctx, sreg = netlink_parse_register(nle, NFTNL_EXPR_META_SREG); expr = netlink_get_register(ctx, loc, sreg); + if (expr == NULL) + return netlink_error(ctx, loc, + "meta statement has no expression"); key = nftnl_expr_get_u32(nle, NFTNL_EXPR_META_KEY); stmt = meta_stmt_alloc(loc, key, expr); @@ -562,6 +572,9 @@ static void netlink_parse_ct_stmt(struct netlink_parse_ctx *ctx, sreg = netlink_parse_register(nle, NFTNL_EXPR_CT_SREG); expr = netlink_get_register(ctx, loc, sreg); + if (expr == NULL) + return netlink_error(ctx, loc, + "ct statement has no expression"); key = nftnl_expr_get_u32(nle, NFTNL_EXPR_CT_KEY); stmt = ct_stmt_alloc(loc, key, expr); |