From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6E8C82F39C1; Fri, 10 Oct 2025 13:22:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760102550; cv=none; b=q23E8pa+yeVvhZ3VNxH2N0GDW0CUA2qWLjEbUhwuNGcd46pqxQPdF7bxJs4nlx0FeEfhoo+2rMX9h6yh5WbcTNOJg3Z4gmnQwRREdvzEufADFeODyfvShPAaB6becChA6dSYzRWfnL8XCgOPDVWMsEfPFVG2MsFdRODyaleTp3A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760102550; c=relaxed/simple; bh=7Of+xAoMGLGcpy2ssrdH7hbjZAZ+jItajeiQxbDca2s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DUtQb/gk3asyJlxs0vl1njZkwoiAU56OoodLqI9sCe52enRARSU/FK0ClfHNV3LeY42tHPOsZ8YPvFYWQLeFuL0xz40zl7SlbPDrcPxTsFH+Jowa/nykP3Semlir0F8AYCFzyy2HrcN/51aE2AI1OtsS1tWi8I1K8OX+vwL/BIg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EKwZ44cx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="EKwZ44cx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EBD34C4CEF1; Fri, 10 Oct 2025 13:22:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760102550; bh=7Of+xAoMGLGcpy2ssrdH7hbjZAZ+jItajeiQxbDca2s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EKwZ44cxZE/yjNJBty7kbpdnAeb+OxIMIMVzasghIprs8Ishio+NhjQj2CXcDxAhR Pm5u4WxMII12n4I6ndW39H1Y29VwAjbPPxg+Ae91bLRbeNCBtx5GJ+/13uSD7NahZO hB/tSD9TUSCM8Augig5zu0o292LwDT+7Ve4OTpf0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+52c1a7d3e5b361ccd346@syzkaller.appspotmail.com, Arnaud Lecomte , Benjamin Tissoires , Romain Sioen Subject: [PATCH 6.6 18/28] hid: fix I2C read buffer overflow in raw_event() for mcp2221 Date: Fri, 10 Oct 2025 15:16:36 +0200 Message-ID: <20251010131331.027492181@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251010131330.355311487@linuxfoundation.org> References: <20251010131330.355311487@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnaud Lecomte commit b56cc41a3ae7323aa3c6165f93c32e020538b6d2 upstream. As reported by syzbot, mcp2221_raw_event lacked validation of incoming I2C read data sizes, risking buffer overflows in mcp->rxbuf during multi-part transfers. As highlighted in the DS20005565B spec, p44, we have: "The number of read-back data bytes to follow in this packet: from 0 to a maximum of 60 bytes of read-back bytes." This patch enforces we don't exceed this limit. Reported-by: syzbot+52c1a7d3e5b361ccd346@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=52c1a7d3e5b361ccd346 Tested-by: syzbot+52c1a7d3e5b361ccd346@syzkaller.appspotmail.com Signed-off-by: Arnaud Lecomte Link: https://patch.msgid.link/20250726220931.7126-1-contact@arnaud-lcm.com Signed-off-by: Benjamin Tissoires Signed-off-by: Romain Sioen Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-mcp2221.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/hid/hid-mcp2221.c +++ b/drivers/hid/hid-mcp2221.c @@ -814,6 +814,10 @@ static int mcp2221_raw_event(struct hid_ } if (data[2] == MCP2221_I2C_READ_COMPL || data[2] == MCP2221_I2C_READ_PARTIAL) { + if (!mcp->rxbuf || mcp->rxbuf_idx < 0 || data[3] > 60) { + mcp->status = -EINVAL; + break; + } buf = mcp->rxbuf; memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]); mcp->rxbuf_idx = mcp->rxbuf_idx + data[3];