nftables/SOURCES/0041-evaluate-prevent-assert-when-evaluating-very-large-s.patch
2026-08-26 08:03:54 -04:00

60 lines
2.2 KiB
Diff

From 8523567b0fc4d2c0f978ee43234d984d5e75795c Mon Sep 17 00:00:00 2001
From: Phil Sutter <psutter@redhat.com>
Date: Fri, 17 Jul 2026 11:08:41 +0200
Subject: [PATCH] evaluate: prevent assert when evaluating very large shift
values
JIRA: https://issues.redhat.com/browse/RHEL-190549
Upstream Status: nftables commit 26723202e600604ab7cf48915507cfcb7a313620
commit 26723202e600604ab7cf48915507cfcb7a313620
Author: Florian Westphal <fw@strlen.de>
Date: Fri Dec 1 14:16:14 2023 +0100
evaluate: prevent assert when evaluating very large shift values
Error out instead of 'nft: gmputil.c:67: mpz_get_uint32: Assertion `cnt <= 1' failed.'.
Fixes: edecd58755a8 ("evaluate: support shifts larger than the width of the left operand")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Phil Sutter <psutter@redhat.com>
---
src/evaluate.c | 9 +++++++--
tests/shell/testcases/bogons/nft-f/huge_shift_assert | 5 +++++
2 files changed, 12 insertions(+), 2 deletions(-)
create mode 100644 tests/shell/testcases/bogons/nft-f/huge_shift_assert
diff --git a/src/evaluate.c b/src/evaluate.c
index 2955ac5..1d13db1 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -1312,9 +1312,14 @@ static int constant_binop_simplify(struct eval_ctx *ctx, struct expr **expr)
static int expr_evaluate_shift(struct eval_ctx *ctx, struct expr **expr)
{
struct expr *op = *expr, *left = op->left, *right = op->right;
- unsigned int shift = mpz_get_uint32(right->value);
- unsigned int max_shift_len;
+ unsigned int shift, max_shift_len;
+ /* mpz_get_uint32 has assert() for huge values */
+ if (mpz_cmp_ui(right->value, UINT_MAX) > 0)
+ return expr_binary_error(ctx->msgs, right, left,
+ "shifts exceeding %u bits are not supported", UINT_MAX);
+
+ shift = mpz_get_uint32(right->value);
if (ctx->stmt_len > left->len)
max_shift_len = ctx->stmt_len;
else
diff --git a/tests/shell/testcases/bogons/nft-f/huge_shift_assert b/tests/shell/testcases/bogons/nft-f/huge_shift_assert
new file mode 100644
index 0000000..7599f85
--- /dev/null
+++ b/tests/shell/testcases/bogons/nft-f/huge_shift_assert
@@ -0,0 +1,5 @@
+table ip t {
+ chain c {
+ counter name meta mark >> 88888888888888888888
+ }
+}