diff options
author | Florian Westphal <fw@strlen.de> | 2024-01-15 14:11:17 +0100 |
---|---|---|
committer | Florian Westphal <fw@strlen.de> | 2024-01-15 14:21:53 +0100 |
commit | 8a66de2a15943b2fbf960967cdbcbd0a148cb114 (patch) | |
tree | 1d919baf5225a0b29b1d21aa95a2148ede3eceb1 | |
parent | e08627257ecfa7dfb68a34a1c8866e7a7e012b15 (diff) |
evaluate: error out when store needs more than one 128bit register of align fixup
Else this gives:
nft: evaluate.c:2983: stmt_evaluate_payload: Assertion `sizeof(data) * BITS_PER_BYTE >= masklen' failed.
For loads, this is already prevented via expr_evaluate_bits() which has:
if (masklen > NFT_REG_SIZE * BITS_PER_BYTE)
return expr_error(ctx->msgs, expr, "mask length %u exceeds allowed maximum of %u\n",
masklen, NFT_REG_SIZE * BITS_PER_BYTE);
But for the store path this isn't called.
The reproducer asks to store a 128 bit integer at bit offset 1, i.e.
17 bytes would need to be munged, but we can only handle up to 16 bytes
(one pseudo-register).
Fixes: 78936d50f306 ("evaluate: add support to set IPv6 non-byte header fields")
Signed-off-by: Florian Westphal <fw@strlen.de>
-rw-r--r-- | src/evaluate.c | 5 | ||||
-rw-r--r-- | tests/shell/testcases/bogons/nft-f/payload_expr_unaligned_store | 1 |
2 files changed, 6 insertions, 0 deletions
diff --git a/src/evaluate.c b/src/evaluate.c index 3b366166..68cfd776 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -3188,6 +3188,11 @@ static int stmt_evaluate_payload(struct eval_ctx *ctx, struct stmt *stmt) payload_byte_size = div_round_up(payload->len + extra_len, BITS_PER_BYTE); + if (payload_byte_size > sizeof(data)) + return expr_error(ctx->msgs, stmt->payload.expr, + "uneven load cannot span more than %u bytes, got %u", + sizeof(data), payload_byte_size); + if (need_csum && payload_byte_size & 1) { payload_byte_size++; diff --git a/tests/shell/testcases/bogons/nft-f/payload_expr_unaligned_store b/tests/shell/testcases/bogons/nft-f/payload_expr_unaligned_store new file mode 100644 index 00000000..c1358df4 --- /dev/null +++ b/tests/shell/testcases/bogons/nft-f/payload_expr_unaligned_store @@ -0,0 +1 @@ +add rule f i @th,1,128 set 1 |