From 9a20f17a7a82ce5ba47047e6c3d2fc921cc1087d Mon Sep 17 00:00:00 2001 From: Xiao Liang Date: Fri, 19 Aug 2022 10:40:23 +0800 Subject: src: Don't parse string as verdict in map In verdict map, string values are accidentally treated as verdicts. For example: table t { map foo { type ipv4_addr : verdict elements = { 192.168.0.1 : bar } } chain output { type filter hook output priority mangle; ip daddr vmap @foo } } Though "bar" is not a valid verdict (should be "jump bar" or something), the string is taken as the element value. Then NFTA_DATA_VALUE is sent to the kernel instead of NFTA_DATA_VERDICT. This would be rejected by recent kernels. On older ones (e.g. v5.4.x) that don't validate the type, a warning can be seen when the rule is hit, because of the corrupted verdict value: [5120263.467627] WARNING: CPU: 12 PID: 303303 at net/netfilter/nf_tables_core.c:229 nft_do_chain+0x394/0x500 [nf_tables] Indeed, we don't parse verdicts during evaluation, but only chain names, which is of type string rather than verdict. For example, "jump $var" is a verdict while "$var" is a string. Fixes: c64457cff967 ("src: Allow goto and jump to a variable") Signed-off-by: Xiao Liang Signed-off-by: Florian Westphal --- tests/shell/testcases/nft-f/0031vmap_string_0 | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100755 tests/shell/testcases/nft-f/0031vmap_string_0 (limited to 'tests') diff --git a/tests/shell/testcases/nft-f/0031vmap_string_0 b/tests/shell/testcases/nft-f/0031vmap_string_0 new file mode 100755 index 00000000..2af846a4 --- /dev/null +++ b/tests/shell/testcases/nft-f/0031vmap_string_0 @@ -0,0 +1,21 @@ +#!/bin/bash + +# Tests parse of corrupted verdicts + +set -e + +RULESET=" +table ip foo { + map bar { + type ipv4_addr : verdict + elements = { + 192.168.0.1 : ber + } + } + + chain ber { + } +}" + +$NFT -f - <<< "$RULESET" && exit 1 +exit 0 -- cgit v1.2.3