From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2AE5D4B95CC; Wed, 30 Sep 2026 15:56:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790783815; cv=none; b=EWgl/K/k5Yz13JZ3EOqknzi+m0cubLUWQCt7JWMOFLCQb7Dc7bLToufu1aB7LYUI8GE9rgNd6dKsCS33RC5JtWhGzaffJ+HddWygxhSIBnyaP9iGqtVIuPg6jPYEjd20MmE1elhxGODRjXuUF9bAQm9IOjNBEFZ5OZ30A9XvqU0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790783815; c=relaxed/simple; bh=j8J7ccGTbREey12Sj6DRx52dQW6jEDzRb5npuYS21p8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=pfPbBclDNqQ/yFLN/SD5Zmq6FxxhLCbDF2Qe8Ma/ECbEWIFiZDwnFWRDyxKpZQ7jVwLe3/JvuLG2mKQSxyYATe0KGt7y+OH3peTOfDt5WmismzbKmPAUvnTzrTLivUoh81Mgdls2A1Uk1gzzinEjQuAHrXbi9cWHbU171smcDEQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MyXcDxoD; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="MyXcDxoD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6020D1F00893; Wed, 30 Sep 2026 15:56:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790783809; bh=NvaVmwOnUAPnBfMGMtlEZUce5qDIzNpvfywJyAbXo0M=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MyXcDxoDF96uyAe9Nbawpv7SH7tShH0+gQVpHJBUR4r2CWzmwnK1dupQKtX9hzhbz f1iAKGnfRcLazWi2ipE6flvoMI7WK/QHI/yqALQvN39GQtOSJM7nY/BjFlyAM1xKk9 ZfTdr/ODgQtUuSxeNedXSRfZ5HrJgZ3Kpel41fTY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?=C3=96mer=20Mete=20Kaya?= , David Heidelberg , Sasha Levin Subject: [PATCH 5.10 529/595] nfc: llcp: fix WKS SAP hijacking via prefix match in nfc_llcp_wks_sap() Date: Wed, 30 Sep 2026 17:27:02 +0200 Message-ID: <20260930152359.082707872@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152347.700140858@linuxfoundation.org> References: <20260930152347.700140858@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ömer Mete Kaya [ Upstream commit 408cff6bd60636df201274d320edfdfde9ed41db ] nfc_llcp_wks_sap() compares only service_name_len bytes, so a short service_name like "u" matches longer WKS strings like "urn:nfc:sn:snep". Fix by requiring exact length match before strncmp(). Fixes: d646960f7986 ("NFC: Initial LLCP support") Signed-off-by: Ömer Mete Kaya Link: https://patch.msgid.link/20260909121437.33744-1-omermetekaya0@gmail.com Signed-off-by: David Heidelberg Signed-off-by: Sasha Levin --- net/nfc/llcp_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c index aebd4b1ab81d3..f4e58fd5cc1fa 100644 --- a/net/nfc/llcp_core.c +++ b/net/nfc/llcp_core.c @@ -369,7 +369,8 @@ static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len) if (wks[sap] == NULL) continue; - if (strncmp(wks[sap], service_name, service_name_len) == 0) + if (strlen(wks[sap]) == service_name_len && + !strncmp(wks[sap], service_name, service_name_len)) return sap; } -- 2.53.0