From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792448968; b=rCnrE3xuts+IlCXF8X/QQHS7MkmaIp5LshgiTqA1RVEA5LklNBM2S2KCu/yfZA/UMgP8 9Wf1YR6kGBgvSHsiMA7hXZ42IYBrM/RHjlOCsI4fIgG877SRVCsKPopNERWElFfB1aLxx Wy+EOLKXFOiEP5K1uSwKiqXHYq3bK8ippubpR5Ds4KwoGF6FQMfDJ45JqgSsxOF8ABbxz UUWIg5fDx0nBJEznqJgB/7meVbi7ilsXlbf9IkR6/62Nk31xpl57LuzcUbmw3PH7fswN9 UQquuQYR3bffQ2omdtzGKEA4afR7xIJGGSwQ650E59qNH4ejGhvR40D9W/BzRlGtDvQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792448968; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=xV2UVHfXlx/HRVoAphySgJRys3jdO5J+/U4pzUx99+w=; b=p1mQ5bkN/TJJ45ZUqjsRMpsLlulkWhqk8HlMFjpTt0sSw2HU16Nxqn8tkzLpBLuVwWHR 6cw9h9KhXjSNj7BIIRN2+fzbdTrOhgFJ5E/lj2i/Erbmabmtg43vylHjGErkR1tcajpkA 5DuMgzFV4poRa9Ocda+bQM1Jkrxzyg3HRfHhAZSocEdicmFWc/ln7rd3muR4CN+eo5g2x Ys3nXhP0XaIuJ4972a+WXo61U1+qYeEpN/FLs3H2LZ+Sl7fsofSXKS/t9LxfJHiuo/hkO f+MBphr2Uup++7530n5TudhDGS8ONHa6VcQchrOH+Aei09NJ59zPjbj9xad5D8elZkw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=mun318D9; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 60575606A319 for ; Mon, 19 Oct 2026 22:29:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=mun318D9 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B99C41F000C4; Mon, 19 Oct 2026 22:29:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792448968; bh=xV2UVHfXlx/HRVoAphySgJRys3jdO5J+/U4pzUx99+w=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=mun318D9+5G3R7F3ry98iOEUuO5h3FLX7HdHlaHYzLQ8cZPKwuHkfr8iY195PIhDM 8OCSFWqBCqULS7bufTyVfDrtY6PPe7SG161H72PJA+ZbcM+3Cyviz6gw4s+5wocO23 QxZrkUWBItKeFSet9n01SKBLh8tb+ZCfZWP8Eg1Q1wY3cCMt25P/gLWNAPj6AdFUvy D+WQBmt4vfCAdzbsV6+XA8ZyFu6qfVrJ+nPiJc5cETBbJDPN1rqR9gyAbAFnTR0nv+ Z2cGrWg/vHKoXjYCBd1Xjd2260jjiPmkHGgX2KLmwI0rgiDj4lx5QTzQ6PXGkcKltH IDGRnup7SBGDA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v15 03/11] scsi: ibmvfc: fix potential NULL pointer dereference on failed queue allocation Reply-To: sashiko-reviews@lists.linux.dev To: "Dave Marquardt" Cc: linux-scsi@vger.kernel.org In-Reply-To: <20261019-ibmvfc-fpin-support-v15-3-a858726e178a@linux.ibm.com> References: <20261019-ibmvfc-fpin-support-v15-0-a858726e178a@linux.ibm.com> <20261019-ibmvfc-fpin-support-v15-3-a858726e178a@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 19 Oct 2026 22:29:27 +0000 X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Medium] scsi: ibmvfc: scrq->cookie not cleared on H_REG_SUB_CRQ failure = in ibmvfc_register_channel() -- commit 09a8086d40f44887491493f172cd7dd44285d18d Author: Tyrel Datwyler scsi: ibmvfc: fix potential NULL pointer dereference on failed queue alloca= tion This commit guards ibmvfc_deregister_channel() against calling H_FREE_SUB_C= RQ on an unregistered sub-CRQ queue and against zeroing an unallocated message buffer. It also adds a KUnit test suite to verify the deregistration guards. > diff --git a/drivers/scsi/ibmvscsi/ibmvfc-core.c b/drivers/scsi/ibmvscsi/= ibmvfc-core.c > index 145d559041f12..0fe6b6f4260ba 100644 > --- a/drivers/scsi/ibmvscsi/ibmvfc-core.c > +++ b/drivers/scsi/ibmvscsi/ibmvfc-core.c > @@ -6449,12 +6449,24 @@ static int ibmvfc_register_channel(struct ibmvfc_= host *vhost, > do { > hcall_rc =3D plpar_hcall_norets(H_FREE_SUB_CRQ, vdev->unit_address, sc= rq->cookie); > } while (hcall_rc =3D=3D H_BUSY || H_IS_LONG_BUSY(hcall_rc)); > + scrq->cookie =3D 0; > reg_failed: > LEAVE; > return rc; > } [Severity: Medium] Should scrq->cookie =3D 0 be placed after the reg_failed label (or should h_reg_sub_crq() avoid writing *cookie on error)? Looking at h_reg_sub_crq() in drivers/scsi/ibmvscsi/ibmvfc-core.c, it unconditionally writes retbuf[0] into *cookie regardless of the return code: static long h_reg_sub_crq(unsigned long unit_address, unsigned long ioba, unsigned long length, unsigned long *cookie, unsigned long *irq) { unsigned long retbuf[PLPAR_HCALL_BUFSIZE]; long rc; rc =3D plpar_hcall(H_REG_SUB_CRQ, retbuf, unit_address, ioba, length); *cookie =3D retbuf[0]; *irq =3D retbuf[1]; return rc; } In plpar_hcall() (arch/powerpc/platforms/pseries/hvCall.S), r5 (unit_addres= s) is moved into r4 before HVSC and r4 is unconditionally stored into retbuf[0] after HVSC, even when HVSC returns an error such as H_PARAMETER or H_RESOUR= CE. When h_reg_sub_crq() fails in ibmvfc_register_channel(): rc =3D h_reg_sub_crq(vdev->unit_address, scrq->msg_token, PAGE_SIZE, &scrq->cookie, &scrq->hw_irq); /* H_CLOSED indicates successful register, but no CRQ partner */ if (rc && rc !=3D H_CLOSED) { dev_warn(dev, "Error registering sub-crq: %d\n", rc); if (rc =3D=3D H_PARAMETER) dev_warn_once(dev, "Firmware may not support MQ\n"); goto reg_failed; } jumping to reg_failed skips scrq->cookie =3D 0, leaving a non-zero value in scrq->cookie. If ibmvfc_deregister_channel() is later called on this queue during reset or teardown (via ibmvfc_dereg_sub_crqs()), won't the new if (scrq->cookie) check evaluate to true and issue H_FREE_SUB_CRQ on a queue that failed registration? [ ... ] --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261019-ibmvfc-fpi= n-support-v15-0-a858726e178a@linux.ibm.com?part=3D3