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 7AF9D48094F; Tue, 25 Aug 2026 13:35:10 +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=1787664911; cv=none; b=QEzhQUeBMXxfk8KkwhXnnqDME6n1+Q/zLHPtEORiTwvrY6pQ1/hzKkD+Nt0DxtCa85ZRhuVwh/+yngTd/qdtjeebJyHo39KA3NoFwnKs0OSIAngwk70JL6/1D7tp70Upmz+F/o0oQXDWu5ifFNPpXhGIpYkvShgYVW+sfDXNbws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787664911; c=relaxed/simple; bh=fGQSu0iJQQTs46t9GdcDEO/eLolhMLACNHvjLleh4pA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Wm3txyJj/ge6ytJG4ObNkBSKZMHeZYgPOXfWFShDWoLjrOwhahSD6ziS8a9GeJUsLRIFH5llhNZ1YqWCv4gwhGvuwvsaybvwJuHEvTBNYRFn9Hf2O+wF2+B9/12Fd10Xjhqz3sLF0FNzb5XgqfcF4hRdi7TKFbMFLd2GjXFDRw4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Tl5J0s1a; 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="Tl5J0s1a" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2EBD1F000E9; Tue, 25 Aug 2026 13:35:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787664910; bh=rAqbNPtpaNyuh7QNYlAiYxNsZPJ0H+8v6aSjLjmQAGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Tl5J0s1aYAyEPkjcvmApDaBVI/CXSXyMEJ7laVcaiw9EqBBGz2K8rFAEsgQLDpwF/ +SPBzX+bltho9V8wdqqGtgToH6GUYuEihBOjMxgZPHXtXpXhNuvBm+QefzqZjBGxHa 620MB9Po7Fl4/nqehpN5Sr4L454iZr20QxnhmEtA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Doruk Tan Ozturk , Simon Horman , David Heidelberg Subject: [PATCH 7.1 044/101] nfc: st21nfca: validate ATR_REQ length against the received frame Date: Tue, 25 Aug 2026 15:25:22 +0200 Message-ID: <20260825132543.743502223@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260825132541.986300899@linuxfoundation.org> References: <20260825132541.986300899@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-Transfer-Encoding: 8bit 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Doruk Tan Ozturk commit 5cdcca5d62a66eda6b774110a44cba67bc1a8d1d upstream. st21nfca_tm_recv_atr_req() checks that the received ATR_REQ frame is at least ST21NFCA_ATR_REQ_MIN_SIZE and that the self-declared atr_req->length is at least sizeof(struct st21nfca_atr_req), but never checks that atr_req->length does not exceed the actual received length (skb->len). st21nfca_tm_send_atr_res() then trusts the declared length: gb_len = atr_req->length - sizeof(struct st21nfca_atr_req); ... memcpy(atr_res->gbi, atr_req->gbi, gb_len); so an RF peer that sends a short frame but sets atr_req->length larger than the frame makes gb_len exceed the general bytes actually present, and the memcpy reads out of bounds past the received skb. Those bytes are placed in the ATR_RES and sent back to the peer (kernel-memory disclosure to a proximity attacker); a larger declared length is an out-of-bounds read (DoS). Reject frames whose declared length exceeds the received length. The adjacent nfc_tm_activated() path in the same function already derives its general-bytes length from skb->len rather than the declared field. Found by 0sec (https://0sec.ai) using automated source analysis; the missing bound is evident from source. Compile-tested. Fixes: 1892bf844ea0 ("NFC: st21nfca: Adding P2P support to st21nfca in Initiator & Target mode") Cc: stable@vger.kernel.org Assisted-by: 0sec:claude-opus-4-8 Signed-off-by: Doruk Tan Ozturk Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260711071301.58071-1-doruk@0sec.ai Signed-off-by: David Heidelberg Signed-off-by: Greg Kroah-Hartman --- drivers/nfc/st21nfca/dep.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/nfc/st21nfca/dep.c +++ b/drivers/nfc/st21nfca/dep.c @@ -205,6 +205,9 @@ static int st21nfca_tm_recv_atr_req(stru if (atr_req->length < sizeof(struct st21nfca_atr_req)) return -EPROTO; + if (atr_req->length > skb->len) + return -EPROTO; + r = st21nfca_tm_send_atr_res(hdev, atr_req); if (r) return r;