From 1cf979a0eb50c443dff24876b69c4558ef55ac60 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 1 Dec 2023 14:16:14 +0100 Subject: [PATCH] evaluate: prevent assert when evaluating very large shift values commit 26723202e600604ab7cf48915507cfcb7a313620 upstream. 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 --- 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 acc69c68b..3f5afd89c 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -1208,9 +1208,14 @@ 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 000000000..7599f8505 --- /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 + } +} -- 2.47.3