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 0F3F051AEEE; Wed, 30 Sep 2026 18:23:02 +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=1790792583; cv=none; b=Kje8QnspT3kwjHvyO/3rma438bhvNeTWUKWc32uZM8zSUX+SeGw6bvIIseICArhgh2Ru4SERm9p13+f/z0MAB2zHmgSyevoWWeyKTiN0DTwShYTdBaO/2hxpNYSRb25Dwr5HwLBS9DuXtB0tzmOqVbpISAGppYL7l4ZKZh4PNuQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792583; c=relaxed/simple; bh=dzpxIWbhsGC97Q7GLLMM3Qs1+SHSwrGBPeTkEqLBvfc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=JKBLF/IQIFFmLygnv3b4nwUW2BIMm2gHCQdn62yYZ/BSsG/acVvOzJy+CzBHbQItiCPvRV31yFWr8gsIIBDlpePTtNALyh+p9JOlwpR203sh33YRFaVZLEhd8PujNjHOp0Ut4OwojhGqeKYuMcVF0R2DlLLG+35hNKCQxCQHgtQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hdqAJG7o; 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="hdqAJG7o" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A4071F00898; Wed, 30 Sep 2026 18:23:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790792582; bh=h4jd0uFLzCrYICtGqjR2IDSNhTcp0AA+3WbyYD8tU1U=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=hdqAJG7oD8hSgLYM/W05OqyKX22jSGG7aIs5PKLNQwT5iLfHghTBuaMIBoG0nMBLp IrLhVIVtEFYT2Zy0rhQD1NRG8Wy7FMjxiQjjoJDgOURqAd98w+/B7sdLcm1zC96HvF 01UmSGlFXYwXjlzsLrPj48OlalibIeZYDpGcebks= 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 5.15 660/752] nfc: llcp: fix WKS SAP hijacking via prefix match in nfc_llcp_wks_sap() Date: Wed, 30 Sep 2026 17:28:50 +0200 Message-ID: <20260930152412.541764872@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@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 5.15-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