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 763F432D7D8; Mon, 27 Oct 2025 18:49:14 +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=1761590954; cv=none; b=gsz/ZLbIUe+MTMrzmXJ3YZaQ+WFMmlQfkCYFkZU/LDLdunFvfnjFfW94Cwi+svMFnAiYAFprUX8d8xUWm8HmZkAM2hPovbxDGdW5E0dKUArIeEvF3jVZlczpoDyd1/21Xuo11NMU+ClkwDaLJWbHReXgMCxfzCSWuJUQlYJKBHw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761590954; c=relaxed/simple; bh=42oaWvoaPn/NensWh47seybcqct+RjHOEQzOecgdvNo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aVQgqYic2PY9RC4q8suSaBiaLM4/ZIO47IKEkyMgh0C8d1XjOFgYVPSwMnLzyqguwa6/QhEGxOfw2tV/qefMVzjSp7clsAW5ZQfJWIZMiT2wbYe+/5cqTrA4FdMDaVxJTDOC67oDlqhhATKLHlAoUlHDIsNDkPmaQSG6DfZQyAc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bGyOqPUn; 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="bGyOqPUn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98402C4CEF1; Mon, 27 Oct 2025 18:49:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761590953; bh=42oaWvoaPn/NensWh47seybcqct+RjHOEQzOecgdvNo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bGyOqPUnjdKjlRs6HsVQMJetLujZOFc4OlkSa2dz6UfcYPXwbmgD4iBqqrpBJ+Gg8 gBiMnkmJ3YTUUkunIsDIxgPjcc6vlFJKs+bqUAnsUjIO697MtaWx9AaXx8keHmrRn5 J35XeFY3rBFUIDrEcTpFo4bVGU7kk3vwcGeYOV90= 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 5.10 012/332] hid: fix I2C read buffer overflow in raw_event() for mcp2221 Date: Mon, 27 Oct 2025 19:31:05 +0100 Message-ID: <20251027183524.945957812@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251027183524.611456697@linuxfoundation.org> References: <20251027183524.611456697@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 5.10-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 @@ -791,6 +791,10 @@ 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];