From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f47.google.com (mail-wr1-f47.google.com [209.85.221.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8911F282F1C for ; Sun, 6 Sep 2026 00:39:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788655175; cv=none; b=e0+wQfwVIVptIH0kJMFfO7o20Q8J4hjQDOIi5Dkowo9qVvlqUJvWQYZpx+wc2LUQBCU8CJC3tZ7NC93FuFQmYVYX9cfvlB9xRwNdGDmnXTQvAYLc6aBSFZTzrKcmjCAWTSRU7Ww/MBX2cHwgd4DuF8JoF7571L7mbqc+phZ5Ghs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788655175; c=relaxed/simple; bh=X/xRmr4GqSFunc+sX8Q9MZBpCDeItpD08dRwHxnF2ng=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=VWM3eT2DV00eA+wYWgMIx+RCadyZGctJvf4jpUiHQIHFE9a5/qqX9qhTX359ZFgJPNDs8lKTckLLMJO4lQu/gvYfH1RvjzLaI+3EmnidWBgFVWeV7F4tz0Nd/PqQqwwCmRxaClZj3e5c95nLzGiwUYSDnnt5egbhYJCZucaeSuw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=NJiSjcih; arc=none smtp.client-ip=209.85.221.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NJiSjcih" Received: by mail-wr1-f47.google.com with SMTP id ffacd0b85a97d-484392e3d33so1479048f8f.2 for ; Sat, 05 Sep 2026 17:39:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788655172; x=1789259972; darn=vger.kernel.org; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=pcaDcOTwZKz9h65XJ4Y1vvTbk/7+OUqBRO3ySthF/ls=; b=NJiSjcihjURX2UzkgQzSq0Pdbs8S80fLRnciuDLxT737lprj4ZgGjIZa7bzMwGQ82F 06zXPQHhwqKGM0NDJx38lNh66UdxcY5r4vGsrY+ogiLSGJmiRkTtSyV+RYRocHYa+Le1 ZNVqtgVHjuQ1egvl82b25mhwztHmyyE+sf093KG1lKc/wNi02ZMOoA1Adp+xsbM6CKbu RGL6ex+R+AotwU6FoewlBSAAXglfxLpzK4pAOrFE0fUTXd4EjAK8r00nPxBJFxmVgXMo 4VS/L007rRBlhV+0elvufupfp7EA85gOeb8wRGv4qW20U7Z2IVHD4wz+OckoXWEq6xsK +aVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788655172; x=1789259972; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=pcaDcOTwZKz9h65XJ4Y1vvTbk/7+OUqBRO3ySthF/ls=; b=hf2aA7I3i2YtR+DxDqSipO1lcpQNy8ahzoT6LDSsykew5ZZiFU8ZHXPiT5o0O/N+UH ycNSrDaFWFnKKOPWCxEwC8+EkiPgwiB37bKkjUBRr3pjLU+SWGbz/feKy2Hhg4tKDZx+ xiZsoDTD/tk0G+Ri0cjJXtV0OMgIFRRrG0r5v7KZ580RFvVOT5er3YYnl5b0r0CWGY2a km6IL+mEN2w5sWeLonZNr90coUMlJwe848B/36u46oeqCThp7GwPhW/8f4D7Qt1WNC2j uSyjNHX6q8XvwR6xUIg0KLQ7L+1o/oIvQmq+Ks9f0lGJeD7FJHon1CO2by2mgupEv51g jKhA== X-Forwarded-Encrypted: i=1; AKwUvBwYoJcej8i3QDAQyhkTR+sVjuyOU+gdtqaqVUk+LdvCMxDecZV6lb6+lrVNsA1CUq5b/iGVOIWuSoR7g+A=@vger.kernel.org X-Gm-Message-State: AFuF++n3d0Mri3CT2vISpraXKGjfr0ftRPRI1wFUqj0tFOf2ly8+Odfp Xq30BxfShz3TfbrCE2Sd7d6WwvWUvdf2USxGMB81TiMuNIF69blNjXs7 X-Gm-Gg: AYBFou2+BBpXToix8GL0NioipD0IV26gkl1nRviw883FOXCgr0VzjYo221UQOSPYcgg UxQY2ZxKTcgYLupk3ac3q3jbjvztketl/V1C1HmM8rZ3Vp22U0o7tgxNu9x+Tzl4FTexBRGS2/m t4W9oWH1jwjzef1TPe4AH9/Zr1NxUqH2Aqktdl+CBhqvZPFcwnuqNFsoPyavxKsVQtJfNmvom6n JtiG0WJGj89fI08BRboNQ376c0Kd3Opx02muNOum/yhvBhTzQVlFrF9To6qnL5Phpo7/O4Mhx6/ 7YTGEDHnYhLJw7wRCnmwn5djtMPLPEcEcGIgydakoljebay6xYfLYW+gx+qp/Je3gKNJ8773+Xv oiBPF2CtdyRoWmFtSPNubhuYCokui5zW24K9Rl8XxYOoxvDKr9qfM7ECSlGzkglNIvTJDMIVk/7 +4lqIeaasJEbWDmgLuU+tv3A2a5MkfABvflvPO+mO87ytPIaH6mCmF7rG7xw== X-Received: by 2002:a05:6000:18a8:b0:485:8c17:975e with SMTP id ffacd0b85a97d-4858c179915mr11914158f8f.32.1788655171649; Sat, 05 Sep 2026 17:39:31 -0700 (PDT) Received: from metepc ([46.197.185.71]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-485885b1320sm17088363f8f.27.2026.09.05.17.39.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Sep 2026 17:39:31 -0700 (PDT) From: =?UTF-8?q?=C3=96mer=20Mete=20Kaya?= To: netdev@vger.kernel.org Cc: david@ixit.cz, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, oe-linux-nfc@lists.linux.dev, linux-kernel@vger.kernel.org, =?UTF-8?q?=C3=96mer=20Mete=20Kaya?= , syzbot+1e3df0852e82c21ca418@syzkaller.appspotmail.com Subject: [PATCH net v3] nfc: llcp: fix slab-out-of-bounds reads when logging service names Date: Sun, 6 Sep 2026 03:38:08 +0300 Message-ID: <20260906003917.627282-1-omermetekaya0@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260905225211.596366-1-omermetekaya0@gmail.com> References: <20260905225211.596366-1-omermetekaya0@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit nfc_llcp_wks_sap() and nfc_llcp_build_sdreq_tlv() pass non-null- terminated strings to pr_debug() using the %s format specifier. The buffers are allocated via kmemdup() or come from netlink attributes and are not guaranteed to be null-terminated, causing __dynamic_pr_debug() to read beyond the allocated region: KASAN: slab-out-of-bounds Read in __dynamic_pr_debug Fix both call sites by using %.*s with the explicit length to limit the output to the actual length of the string. Reported-by: syzbot+1e3df0852e82c21ca418@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=1e3df0852e82c21ca418 Signed-off-by: Ömer Mete Kaya --- v3: Also fix identical issue in nfc_llcp_build_sdreq_tlv() as suggested by Sashiko review. net/nfc/llcp_commands.c | 2 +- net/nfc/llcp_core.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c index ca89fe967d6a..1213946ce91f 100644 --- a/net/nfc/llcp_commands.c +++ b/net/nfc/llcp_commands.c @@ -135,7 +135,7 @@ struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, const char *uri, { struct nfc_llcp_sdp_tlv *sdreq; - pr_debug("uri: %s, len: %zu\n", uri, uri_len); + pr_debug("uri: %.*s, len: %zu\n", (int)uri_len, uri); /* sdreq->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */ if (WARN_ON_ONCE(uri_len > U8_MAX - 4)) diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c index cac1b5487064..fda236e4d9fd 100644 --- a/net/nfc/llcp_core.c +++ b/net/nfc/llcp_core.c @@ -341,7 +341,7 @@ static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len) { int sap, num_wks; - pr_debug("%s\n", service_name); + pr_debug("%.*s\n", (int)service_name_len, service_name); if (service_name == NULL) return -EINVAL; -- 2.55.0