From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.216.245.30 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793199450; b=hjqQmi3DMazWcNj0igiRsIbCmW2WskbWZa7kMEaHqe5TC5PH44/+pa1G2IT7aEPG43D2 jzRdA+K5mdCb0FFHjdbeOSYZPcs0DHKRxKaXZG4m8I8VyyALqg3ymVjQ0h7z88sshe/4m DXlEW2AheHoQj0EU/s9e9/UHXsoKtqac3Zi+1oBQYn8DURBzGWbWkRefa3KeNnBHC9VID /hgNgOLmTFmIY3vi0NoAwxcfQqGUSiO5VvwtD0ntfAYtJN19K+giS+fju9ERZYLCpfHRW KmskNeY3+hbMdSJu0iwaLpvZBv5pe9hw24nlz7VPE2kDGH/p09TveMVOqdGcdIPvGJA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793199450; h=DMARC-Filter:Received:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=F67JmIjCUTUbq2UeYUGoENmrWM1p0mhpp71IhxLgVEc=; b=2gmVEE2P4LJG73lBKH0ztM1OjlSUUSSIZVZOgJ/+82WnFkDZtSvwbRYp2rvbxkN2ncKm lV8ft8FPWVaLXVDShDmfosqV640vVFRIpnsy3+kQrKv1/unYNDU5fm0vEp5tTILhoDmBz dLelG0M1pXyCOBoAzEThqqNEEO34wKqb56I7SPMiJzK3GSyWzKa8s1OLx40ruHVlj4Puu W7F66WmMzJcFwdMMBjCGZcQS6li6kvHUnGWCr3H/Hglhw2tzloyfrZhsZ6UWJo6f0JMX5 WoZRDR8+vl/Nj7rKeUsl7yd2V2IXUkayUbCbqgC7p2YP+Z2W34TMCanZDeZy5F48Wrw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=strlen.de; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc; arc=none smtp.remote-ip=91.216.245.30 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 181A8606A31D for ; Wed, 28 Oct 2026 14:57:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 181A8606A31D Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=Chamillionaire.breakpoint.cc Received: by Chamillionaire.breakpoint.cc (Postfix, from userid 1003) id 64F6B609D0; Wed, 28 Oct 2026 15:57:28 +0100 (CET) From: Florian Westphal To: Cc: Florian Westphal Subject: [PATCH libftnl 10/12] src: set_elem: list_del before freeing Date: Wed, 28 Oct 2026 15:56:30 +0100 Message-ID: <20261028145632.7089-11-fw@strlen.de> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261028145632.7089-1-fw@strlen.de> References: <20261028145632.7089-1-fw@strlen.de> X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit LLM finding: nftnl_expr_free() calls xfree(expr). It never calls list_del(&expr->head). After the loop, expr_list.next/.prev point into freed heap memory. Next list_add results in UaF. Looks like noone does such re-use, but as the API allows it, make this safe. Signed-off-by: Florian Westphal --- src/set_elem.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/set_elem.c b/src/set_elem.c index 3504a2306e47..0170d0ccefd1 100644 --- a/src/set_elem.c +++ b/src/set_elem.c @@ -88,8 +88,10 @@ void nftnl_set_elem_unset(struct nftnl_set_elem *s, uint16_t attr) break; case NFTNL_SET_ELEM_EXPR: case NFTNL_SET_ELEM_EXPRESSIONS: - list_for_each_entry_safe(expr, tmp, &s->expr_list, head) + list_for_each_entry_safe(expr, tmp, &s->expr_list, head) { + list_del(&expr->head); nftnl_expr_free(expr); + } break; case NFTNL_SET_ELEM_OBJREF: xfree(s->objref); @@ -167,8 +169,10 @@ __nftnl_set_elem_set(struct nftnl_set_elem *s, uint16_t attr, const void *data, return -1; break; case NFTNL_SET_ELEM_EXPR: - list_for_each_entry_safe(expr, tmp, &s->expr_list, head) + list_for_each_entry_safe(expr, tmp, &s->expr_list, head) { + list_del(&expr->head); nftnl_expr_free(expr); + } expr = (void *)data; list_add(&expr->head, &s->expr_list); -- 2.55.0