From 6ecccc872b9cbed921af10e32d1a628eb6a74c01 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Mon, 27 Jan 2020 16:11:41 +0100 Subject: [PATCH] netlink: Fix leaks in netlink_parse_cmp() Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1793030 Upstream Status: nftables commit e957bd9f10d5e commit e957bd9f10d5e36671a0b0398e2037fc6201275b Author: Phil Sutter Date: Mon Jan 20 14:48:26 2020 +0100 netlink: Fix leaks in netlink_parse_cmp() This fixes several problems at once: * Err path would leak expr 'right' in two places and 'left' in one. * Concat case would leak 'right' by overwriting the pointer. Introduce a temporary variable to hold the new pointer. Fixes: 6377380bc265f ("netlink_delinearize: handle relational and lookup concat expressions") Signed-off-by: Phil Sutter Acked-by: Pablo Neira Ayuso --- src/netlink_delinearize.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c index 06a0312..88dbd5a 100644 --- a/src/netlink_delinearize.c +++ b/src/netlink_delinearize.c @@ -274,7 +274,7 @@ static void netlink_parse_cmp(struct netlink_parse_ctx *ctx, { struct nft_data_delinearize nld; enum nft_registers sreg; - struct expr *expr, *left, *right; + struct expr *expr, *left, *right, *tmp; enum ops op; sreg = netlink_parse_register(nle, NFTNL_EXPR_CMP_SREG); @@ -291,19 +291,26 @@ static void netlink_parse_cmp(struct netlink_parse_ctx *ctx, if (left->len > right->len && expr_basetype(left) != &string_type) { - return netlink_error(ctx, loc, "Relational expression size mismatch"); + netlink_error(ctx, loc, "Relational expression size mismatch"); + goto err_free; } else if (left->len > 0 && left->len < right->len) { expr_free(left); left = netlink_parse_concat_expr(ctx, loc, sreg, right->len); if (left == NULL) - return; - right = netlink_parse_concat_data(ctx, loc, sreg, right->len, right); - if (right == NULL) - return; + goto err_free; + tmp = netlink_parse_concat_data(ctx, loc, sreg, right->len, right); + if (tmp == NULL) + goto err_free; + expr_free(right); + right = tmp; } expr = relational_expr_alloc(loc, op, left, right); ctx->stmt = expr_stmt_alloc(loc, expr); + return; +err_free: + expr_free(left); + expr_free(right); } static void netlink_parse_lookup(struct netlink_parse_ctx *ctx, -- 1.8.3.1