From nobody Tue Oct 7 19:26:32 2025 Received: from smtp105.iad3a.emailsrvr.com (smtp105.iad3a.emailsrvr.com [173.203.187.105]) (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 EBFB62BD588 for ; Mon, 7 Jul 2025 14:06:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=173.203.187.105 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751897210; cv=none; b=YqN2jt+rwLZR9XKmqHfPtSoqGZF2s6UKF9YRcrUFVIc01UdeXo/57wrM1+5R4Z903dW71BstV3zTW2pnibhMAtsSJoS9XqSXzPD7JDxLa8fQdcHXzVyGonvKUyegSejFDxkgUCrpVX/3IpcSYfoS5I95FVn//U3QpGCczGenns0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751897210; c=relaxed/simple; bh=JHkCVKeT8xiLSJmkc3nLiDElL7x78P/9DwQm8Z2ai3c=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=dglv/O5Lm9N0HR0gFRQBVoRqf8mYnDtcll6TAlWXCKOfzHmsw+hUsq0OsogR7uhyYEQ9ExMfEXEp1U2l0kCyXS5pCYm+5qeLf5zJuhqDPJVrX1dhvbCfDmIM1PIMDo8cgS7UGOh9odPYrFwTFn3WAoUUKHtv+vrlw0XLJFHHlbc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mev.co.uk; spf=pass smtp.mailfrom=mev.co.uk; dkim=pass (1024-bit key) header.d=mev.co.uk header.i=@mev.co.uk header.b=kGmV4Niz; arc=none smtp.client-ip=173.203.187.105 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mev.co.uk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mev.co.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mev.co.uk header.i=@mev.co.uk header.b="kGmV4Niz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mev.co.uk; s=20221208-6x11dpa4; t=1751896667; bh=JHkCVKeT8xiLSJmkc3nLiDElL7x78P/9DwQm8Z2ai3c=; h=From:To:Subject:Date:From; b=kGmV4NizXKuRVCb7ts8mbJmDjhkQtwxz67EayJB1ML9bSzh9LsSDbqgrcYSry+gQQ sbkLe5/yrlWYq74S0B9/s9ZIHJ+sJL9qOQ49GYJGC3dP9FxXGhuUqWHZHbSF1FSx+t dtstMO/kNEqvru+W7sbgcCvn6ULejuQaRLQ+p4QU= X-Auth-ID: abbotti@mev.co.uk Received: by smtp22.relay.iad3a.emailsrvr.com (Authenticated sender: abbotti-AT-mev.co.uk) with ESMTPSA id 70B0D1982; Mon, 7 Jul 2025 09:57:46 -0400 (EDT) From: Ian Abbott To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , Ian Abbott , H Hartley Sweeten , stable@vger.kernel.org Subject: [PATCH] comedi: das6402: Fix bit shift out of bounds Date: Mon, 7 Jul 2025 14:57:37 +0100 Message-ID: <20250707135737.77448-1-abbotti@mev.co.uk> X-Mailer: git-send-email 2.47.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Classification-ID: 5066d715-a91c-4619-9ca4-c855c2d9a7dc-1-1 Content-Type: text/plain; charset="utf-8" When checking for a supported IRQ number, the following test is used: /* IRQs 2,3,5,6,7, 10,11,15 are valid for "enhanced" mode */ if ((1 << it->options[1]) & 0x8cec) { However, `it->options[i]` is an unchecked `int` value from userspace, so the shift amount could be negative or out of bounds. Fix the test by requiring `it->options[1]` to be within bounds before proceeding with the original test. Valid `it->options[1]` values that select the IRQ will be in the range [1,15]. The value 0 explicitly disables the use of interrupts. Fixes: 79e5e6addbb1 ("staging: comedi: das6402: rewrite broken driver") Cc: # 5.13+ Signed-off-by: Ian Abbott --- Patch does not apply cleanly to longterm kernels 5.4.x and 5.10.x. --- drivers/comedi/drivers/das6402.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/comedi/drivers/das6402.c b/drivers/comedi/drivers/das6= 402.c index 68f95330de45..7660487e563c 100644 --- a/drivers/comedi/drivers/das6402.c +++ b/drivers/comedi/drivers/das6402.c @@ -567,7 +567,8 @@ static int das6402_attach(struct comedi_device *dev, das6402_reset(dev); =20 /* IRQs 2,3,5,6,7, 10,11,15 are valid for "enhanced" mode */ - if ((1 << it->options[1]) & 0x8cec) { + if (it->options[1] > 0 && it->options[1] < 16 && + (1 << it->options[1]) & 0x8cec) { ret =3D request_irq(it->options[1], das6402_interrupt, 0, dev->board_name, dev); if (ret =3D=3D 0) { --=20 2.47.2