Hi Florian,
On Wed, Dec 06, 2023 at 02:07:09PM +0100, Florian Westphal wrote:
> 'meta mark set vlan id map { 1 : 0x00000001, 4095 : 0x00004095 }' will
> crash. Reason is that the l2 dependency generated here is errounously
> expanded to a 32bit-one, so the evaluation path won't recognize this
> as a L2 dependency. Therefore, pctx->stacked_ll_count is 0 and
> __expr_evaluate_payload() crashes with a null deref when
> dereferencing pctx->stacked_ll[0].
>
> Reset stmt_len in expr_evaluate_relational() to avoid
> this.
See patch attached, I mangled your original patch with this:
Consolidate stmt_len reset in stmt_evaluate() to avoid this.
stmt_evaluate_meta() and stmt_evaluate_ct() already resets it, payload
dependencies also manually reset this before calling stmt_evaluate() to
evaluate such dependency.
See attachment. The idea is to consolidate all these ctx->stmt_len
resets.
>From ec20bdac25c11d0ec7b7867c1b68324e9d2ab8d9 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@xxxxxxxxx>
Date: Wed, 6 Dec 2023 17:34:08 +0100
Subject: [PATCH] evaluate: reset statement length context for relational
expressions
'meta mark set vlan id map { 1 : 0x00000001, 4095 : 0x00004095 }' will
crash. Reason is that the l2 dependency generated here is errounously
expanded to a 32bit-one, so the evaluation path won't recognize this
as a L2 dependency. Therefore, pctx->stacked_ll_count is 0 and
__expr_evaluate_payload() crashes with a null deref when
dereferencing pctx->stacked_ll[0].
Consolidate stmt_len reset in stmt_evaluate() to avoid this.
stmt_evaluate_meta() and stmt_evaluate_ct() already resets it, payload
dependencies also manually reset this before calling stmt_evaluate() to
evaluate such dependency.
nft-test.py gains a fugly hack to tolerate '!map typeof vlan id : meta mark'.
For more generic support we should find something more acceptable, e.g.
!map typeof( everything here is a key or data ) timeout ...
Fixes: 57f092a87fc4 ("evaluate: reset statement length context only for set mappings")
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
src/evaluate.c | 7 +++----
src/payload.c | 2 --
tests/py/any/meta.t | 4 ++++
tests/py/any/meta.t.payload | 26 ++++++++++++++++++++++++++
tests/py/any/meta.t.payload.bridge | 21 +++++++++++++++++++++
tests/py/nft-test.py | 17 +++++++++++++----
6 files changed, 67 insertions(+), 10 deletions(-)
create mode 100644 tests/py/any/meta.t.payload.bridge
diff --git a/src/evaluate.c b/src/evaluate.c
index c32857c75565..440637ed0e39 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -818,6 +818,7 @@ static int __expr_evaluate_payload(struct eval_ctx *ctx, struct expr *expr)
desc->name,
payload->payload.desc->name);
+ assert(pctx->stacked_ll_count);
payload->payload.offset += pctx->stacked_ll[0]->length;
rule_stmt_insert_at(ctx->rule, nstmt, ctx->stmt);
return 1;
@@ -3171,8 +3172,6 @@ static int stmt_evaluate_meta(struct eval_ctx *ctx, struct stmt *stmt)
stmt->meta.tmpl->len,
stmt->meta.tmpl->byteorder,
&stmt->meta.expr);
- ctx->stmt_len = 0;
-
if (ret < 0)
return ret;
@@ -3200,8 +3199,6 @@ static int stmt_evaluate_ct(struct eval_ctx *ctx, struct stmt *stmt)
stmt->ct.tmpl->len,
stmt->ct.tmpl->byteorder,
&stmt->ct.expr);
- ctx->stmt_len = 0;
-
if (ret < 0)
return -1;
@@ -4497,6 +4494,8 @@ int stmt_evaluate(struct eval_ctx *ctx, struct stmt *stmt)
erec_destroy(erec);
}
+ ctx->stmt_len = 0;
+
switch (stmt->ops->type) {
case STMT_CONNLIMIT:
case STMT_COUNTER:
diff --git a/src/payload.c b/src/payload.c
index 140ca50addf7..66c93e5064cf 100644
--- a/src/payload.c
+++ b/src/payload.c
@@ -430,7 +430,6 @@ static int payload_add_dependency(struct eval_ctx *ctx,
dep = relational_expr_alloc(&expr->location, OP_EQ, left, right);
stmt_len = ctx->stmt_len;
- ctx->stmt_len = 0;
stmt = expr_stmt_alloc(&dep->location, dep);
if (stmt_evaluate(ctx, stmt) < 0) {
@@ -565,7 +564,6 @@ int payload_gen_dependency(struct eval_ctx *ctx, const struct expr *expr,
"for this family");
stmt_len = ctx->stmt_len;
- ctx->stmt_len = 0;
stmt = meta_stmt_meta_iiftype(&expr->location, type);
if (stmt_evaluate(ctx, stmt) < 0) {
diff --git a/tests/py/any/meta.t b/tests/py/any/meta.t
index 12fabb79f5f9..718c7ad96186 100644
--- a/tests/py/any/meta.t
+++ b/tests/py/any/meta.t
@@ -224,3 +224,7 @@ time > "2022-07-01 11:00:00" accept;ok;meta time > "2022-07-01 11:00:00" accept
meta time "meh";fail
meta hour "24:00" drop;fail
meta day 7 drop;fail
+
+meta mark set vlan id map { 1 : 0x00000001, 4095 : 0x00004095 };ok
+!map1 typeof vlan id : meta mark;ok
+meta mark set vlan id map @map1;ok
diff --git a/tests/py/any/meta.t.payload b/tests/py/any/meta.t.payload
index 16dc12118bac..d841377ec6cd 100644
--- a/tests/py/any/meta.t.payload
+++ b/tests/py/any/meta.t.payload
@@ -1072,3 +1072,29 @@ ip test-ip4 input
[ byteorder reg 1 = hton(reg 1, 8, 8) ]
[ cmp gt reg 1 0xf3a8fd16 0x00a07719 ]
[ immediate reg 0 accept ]
+
+# meta mark set vlan id map { 1 : 0x00000001, 4095 : 0x00004095 }
+__map%d test-ip4 b size 2
+__map%d test-ip4 0
+ element 00000100 : 00000001 0 [end] element 0000ff0f : 00004095 0 [end]
+ip test-ip4 input
+ [ meta load iiftype => reg 1 ]
+ [ cmp eq reg 1 0x00000001 ]
+ [ payload load 2b @ link header + 12 => reg 1 ]
+ [ cmp eq reg 1 0x00000081 ]
+ [ payload load 2b @ link header + 14 => reg 1 ]
+ [ bitwise reg 1 = ( reg 1 & 0x0000ff0f ) ^ 0x00000000 ]
+ [ lookup reg 1 set __map%d dreg 1 ]
+ [ meta set mark with reg 1 ]
+
+# meta mark set vlan id map @map1
+ip test-ip4 input
+ [ meta load iiftype => reg 1 ]
+ [ cmp eq reg 1 0x00000001 ]
+ [ payload load 2b @ link header + 12 => reg 1 ]
+ [ cmp eq reg 1 0x00000081 ]
+ [ payload load 2b @ link header + 14 => reg 1 ]
+ [ bitwise reg 1 = ( reg 1 & 0x0000ff0f ) ^ 0x00000000 ]
+ [ lookup reg 1 set map1 dreg 1 ]
+ [ meta set mark with reg 1 ]
+
diff --git a/tests/py/any/meta.t.payload.bridge b/tests/py/any/meta.t.payload.bridge
new file mode 100644
index 000000000000..829a29b99974
--- /dev/null
+++ b/tests/py/any/meta.t.payload.bridge
@@ -0,0 +1,21 @@
+# meta mark set vlan id map { 1 : 0x00000001, 4095 : 0x00004095 }
+__map%d test-bridge b size 2
+__map%d test-bridge 0
+ element 00000100 : 00000001 0 [end] element 0000ff0f : 00004095 0 [end]
+bridge test-bridge input
+ [ payload load 2b @ link header + 12 => reg 1 ]
+ [ cmp eq reg 1 0x00000081 ]
+ [ payload load 2b @ link header + 14 => reg 1 ]
+ [ bitwise reg 1 = ( reg 1 & 0x0000ff0f ) ^ 0x00000000 ]
+ [ lookup reg 1 set __map%d dreg 1 ]
+ [ meta set mark with reg 1 ]
+
+# meta mark set vlan id map @map1
+bridge test-bridge input
+ [ payload load 2b @ link header + 12 => reg 1 ]
+ [ cmp eq reg 1 0x00000081 ]
+ [ payload load 2b @ link header + 14 => reg 1 ]
+ [ bitwise reg 1 = ( reg 1 & 0x0000ff0f ) ^ 0x00000000 ]
+ [ lookup reg 1 set map1 dreg 1 ]
+ [ meta set mark with reg 1 ]
+
diff --git a/tests/py/nft-test.py b/tests/py/nft-test.py
index 9a25503d1f38..a7d27c25f9fe 100755
--- a/tests/py/nft-test.py
+++ b/tests/py/nft-test.py
@@ -368,9 +368,9 @@ def set_add(s, test_result, filename, lineno):
flags = "flags %s; " % flags
if s.data == "":
- cmd = "add set %s %s { type %s;%s %s}" % (table, s.name, s.type, s.timeout, flags)
+ cmd = "add set %s %s { %s;%s %s}" % (table, s.name, s.type, s.timeout, flags)
else:
- cmd = "add map %s %s { type %s : %s;%s %s}" % (table, s.name, s.type, s.data, s.timeout, flags)
+ cmd = "add map %s %s { %s : %s;%s %s}" % (table, s.name, s.type, s.data, s.timeout, flags)
ret = execute_cmd(cmd, filename, lineno)
@@ -410,7 +410,7 @@ def map_add(s, test_result, filename, lineno):
if flags != "":
flags = "flags %s; " % flags
- cmd = "add map %s %s { type %s : %s;%s %s}" % (table, s.name, s.type, s.data, s.timeout, flags)
+ cmd = "add map %s %s { %s : %s;%s %s}" % (table, s.name, s.type, s.data, s.timeout, flags)
ret = execute_cmd(cmd, filename, lineno)
@@ -1144,11 +1144,16 @@ def set_process(set_line, filename, lineno):
tokens = set_line[0].split(" ")
set_name = tokens[0]
- set_type = tokens[2]
+ parse_typeof = tokens[1] == "typeof"
+ set_type = tokens[1] + " " + tokens[2]
set_data = ""
set_flags = ""
i = 3
+ if parse_typeof and tokens[i] == "id":
+ set_type += " " + tokens[i]
+ i += 1;
+
while len(tokens) > i and tokens[i] == ".":
set_type += " . " + tokens[i+1]
i += 2
@@ -1157,6 +1162,10 @@ def set_process(set_line, filename, lineno):
set_data = tokens[i+1]
i += 2
+ if parse_typeof and tokens[i] == "mark":
+ set_data += " " + tokens[i]
+ i += 1;
+
if len(tokens) == i+2 and tokens[i] == "timeout":
timeout = "timeout " + tokens[i+1] + ";"
i += 2
--
2.30.2
