diff options
| author | Thomas Haller <thaller@redhat.com> | 2023-08-29 14:53:33 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2023-08-29 19:55:33 +0200 |
| commit | 7e6aa6db1fe5b14b5d224da11b077c50cc954efa (patch) | |
| tree | ae1cf4a7cd92d844d162875df014a6a89e49a52c /src/evaluate.c | |
| parent | 472acb9997a3eb798c3bb3c5b1a6dc3d9c740ada (diff) | |
evaluate: fix check for truncation in stmt_evaluate_log_prefix()
Otherwise, nft crashes with prefix longer than 127 bytes:
# nft add rule x y log prefix \"eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee\"
==159385==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffed5bf4a10 at pc 0x7f3134839269 bp 0x7ffed5bf48b0 sp 0x7ffed5bf4060
WRITE of size 129 at 0x7ffed5bf4a10 thread T0
#0 0x7f3134839268 in __interceptor_memset ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:778
#1 0x7f3133e3074e in __mpz_export_data /tmp/nftables/src/gmputil.c:110
#2 0x7f3133d21d3c in expr_to_string /tmp/nftables/src/expression.c:192
#3 0x7f3133ded103 in netlink_gen_log_stmt /tmp/nftables/src/netlink_linearize.c:1148
#4 0x7f3133df33a1 in netlink_gen_stmt /tmp/nftables/src/netlink_linearize.c:1682
[...]
Fixes: e76bb3794018 ('src: allow for variables in the log prefix string')
Signed-off-by: Thomas Haller <thaller@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'src/evaluate.c')
| -rw-r--r-- | src/evaluate.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/evaluate.c b/src/evaluate.c index eb834eae..4c02a9cd 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -4150,7 +4150,7 @@ static int stmt_evaluate_log_prefix(struct eval_ctx *ctx, struct stmt *stmt) SNPRINTF_BUFFER_SIZE(ret, size, len, offset); } - if (len == NF_LOG_PREFIXLEN) + if (len == 0) return stmt_error(ctx, stmt, "log prefix is too long"); expr = constant_expr_alloc(&stmt->log.prefix->location, &string_type, |