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 E26B83C1411 for ; Tue, 23 Jun 2026 22:28:31 +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=1782253712; cv=none; b=bIi/bTt1lgTgxmolIFtsJoSHX0TasJMaU08EkZxi4hLPTJdI00O01ZBBh72NQy/Fu6eWbhG0oeXIgPI4UotZJ0X/CodveADsjO/13R4TVUcJUFHiPg0X8arNhLniynl3wMZQMILMHHYr9Pj8FdUqDMP6b4P8CgsQBDbNphSs9fY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782253712; c=relaxed/simple; bh=rgP8Tqmd9PYeAKiD749qsCytgtvgwZlrHNsxYWKuq3g=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=Ut7S+G0rFAiPjCUCD1ocVYgQD0EwMfZyuJkT655g3kDl/5yS+BnXw2vZEYnYXTOwJAw/SXJCQZPNPVMFHj2PxMnWubjnAxLfyybTu1mhUb7PXPffAfCYc7yRiWou3hsUAxDZbd9EfSNMi0OGUPzyTwfLhZ9NZSkzBbMlxYdmOhQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GqJGYCN4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GqJGYCN4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 755ED1F000E9; Tue, 23 Jun 2026 22:28:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782253711; bh=sQh2X2KVbLC76/V5DqE0dzxsSn1srlGayn9HPwwquUk=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=GqJGYCN4hJsALLbL7ynOJ+4INjRRRo0QlDA0lxecGKMeP2SkIZtx/D3zamEBgOBvd /QMyecNJal8nsiFxJKZdfWp/Fkzb5iSqBUyrZNoa4o40enuCOUPWACJwdQRdEZIF5j itKjElguxopXEWTLfKAAMz6jD3ahWzcoyVz8CAcDZy4jDA+elSfEDcc163BZiArJjT /zgyFg0BRqwpGysYAXEJK6kTkQci4/74/xwuPWOh0yxI9gOyZUY3U8i4x461Lo2tsL gxO2NCdF1C86gKCbiu5Rc5yqum+1qpnCQgEfZBGJT52Q0Udz5C+IiKWbUPIU7vY3Zr 6r93zbKuQ5sRg== From: sashiko-bot@kernel.org Subject: Re: [PATCH net v3 1/2] iov_iter: export iov_iter_restore Reply-To: sashiko-reviews@lists.linux.dev To: "Octavian Purdila" Cc: kvm@vger.kernel.org In-Reply-To: <20260622222757.2130402-2-tavip@google.com> References: <20260622222757.2130402-1-tavip@google.com> <20260622222757.2130402-2-tavip@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 23 Jun 2026 22:28:30 +0000 Message-Id: <20260623222831.755ED1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: Pre-existing issues: - [High] Exporting `iov_iter_restore` exposes a pre-existing logic error wh= ere restoring an `ITER_KVEC` iterator falsely triggers a `WARN_ON_ONCE`. -- commit b7b5854a768fd37654ad61552651a21df8d14c8f Author: Octavian Purdila iov_iter: export iov_iter_restore Export iov_iter_restore so that it can be used by modules. This is needed by the virtio vsock transport to restore the msg_iter state when transmission fails. > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > index 273919b161617..f5df63961fb24 100644 > --- a/lib/iov_iter.c > +++ b/lib/iov_iter.c > @@ -1491,6 +1491,7 @@ void iov_iter_restore(struct iov_iter *i, struct io= v_iter_state *state) > i->__iov -=3D state->nr_segs - i->nr_segs; > i->nr_segs =3D state->nr_segs; > } > +EXPORT_SYMBOL_GPL(iov_iter_restore); [Severity: High] This isn't a bug introduced by this patch, but exporting this function to modules exposes a pre-existing issue when restoring an ITER_KVEC iterator. Looking at iov_iter_restore() in lib/iov_iter.c: void iov_iter_restore(struct iov_iter *i, struct iov_iter_state *state) { if (WARN_ON_ONCE(!iov_iter_is_bvec(i) && !iter_is_iovec(i) && !iter_is_ubuf(i)) && !iov_iter_is_kvec(i)) return; Because !iov_iter_is_kvec(i) is placed outside the WARN_ON_ONCE() parenthes= es, restoring an ITER_KVEC evaluates to WARN_ON_ONCE(true) && false. This safely skips the early return, but still incorrectly triggers the warning, which c= an lead to a panic on systems with panic_on_warn enabled. Since ITER_KVEC is often used for kernel-originated network and storage dat= a, does exporting this to modules like virtio vsock create a risk of falsely triggering warnings or a denial of service condition? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260622222757.2130= 402-1-tavip@google.com?part=3D1