From nobody Sun May 24 20:33:36 2026 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1E0B3CC7DC for ; Thu, 21 May 2026 13:05:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779368715; cv=none; b=HDqvHepiIpKzPjsr99uCmDAM8OGd8UO1CYtn48zLSZ1uP2auEeVU2mtzUJin1WejC1HbgmVcXzQvID8uFykeL7QNbIkbejHZJjCr241u4mX1ktxxquOIVhvPWtWDAeK4mb2OLZIINnoaFrmmZsK+Ov3x8dunWlbQ5Aqc1utjEHI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779368715; c=relaxed/simple; bh=oZ69NwmdNZWOSPG7LLZeya/S5cIfZyUDGQrjlvo4/3c=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=YeNskSjAYRLe/0XNMrbNwJJ38T7km3UwRM18zM4uIVkjStLIjlcdsQMNjpp2Ktg7DC3Zv0MiJN8NuEAGSVyRCc5Xr5X/gVqB8iBQ3SqXRht7r3rNH8i9f+2AXwANreNEd8YDbIkuBOnI1EWrcuW5+dSClRYNCfpTUgToalegYAE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--smostafa.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=u3yt9vfk; arc=none smtp.client-ip=209.85.128.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--smostafa.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="u3yt9vfk" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-48fe3e73da6so29525375e9.2 for ; Thu, 21 May 2026 06:05:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779368712; x=1779973512; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:from:to:cc:subject:date:message-id:reply-to; bh=oiB5teETNAJO+fDl6KAzGRJpV3WpZWrKa7655moiG8g=; b=u3yt9vfkrMtyC5qtxdXTan/pBtTliAWBaTkg4hwBr5KUG3+PH3xutoA9nlwA3Wl0St b49XOXQPVuEiw8Ku5ryk1rLuncVF3aVH8NiArpadj1MyLjgfBJi1+i679KsQ356IpQUS bNe+DBfwBwLAbzUNkMPqCqsjW2oOBrmb52HQsXfc7Y2REKBvcXkZYkqRRqVmTGrg7kU7 mXugVFoGxceRN0pM1Znich1I7LW8X/gnxcJkxVGnjr8mXZWC3uMkNywhTSYBK5J4DdVN V5ZiVaqvXcUPDsoIEgZLdKM6LdHWzNmIXDDXjFd5A9m8SwR+t2TfhHyFA1o+8uFWj5Mq sdsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779368712; x=1779973512; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=oiB5teETNAJO+fDl6KAzGRJpV3WpZWrKa7655moiG8g=; b=F7AHd+b1Nnst9cQ+3nVaZcNCvIcXvwepI6KQ/9XAlidYV+RrqdWARGGsCXktuNDEMl MFBWfh2ntzlQnZC64nstK+AidkDZraCv6hHgBmCdgQ+FCDrUwmLV60pwDsFhHt/G4Opj OO9ftCivDVG0K9YmGkLMMnjvM13S3tYJllYKnqv1EBblCN5WyvPnp7o0IP0NBSohZnTd QXNuZra0M2298IeJH0ZZe7uBlusJX0WDDoO97kobypthN0zoj3TvbxVCKjIFUZzcIahg rfvmaoTkXAHVlTlp2OFfM5WCRAp36/nOPCf+ES8D/ukhdXDPG959y0O6wMUZA74TLXzo 9Yzg== X-Forwarded-Encrypted: i=1; AFNElJ9CpFpC853yq7oG+qvy7X2dm6VTfsUDhbRwtypbcrM0lnBXWD58q94Sd0qSZw84ua2t1yGLZsT90Hw0t2M=@vger.kernel.org X-Gm-Message-State: AOJu0YwtJyfl2i1g/VthWHSPI6nKyj5nnuX7XffemoWz1Tr65Ge8t99T /kJ3VjbMBnf5mS67fRVQ8gUxQBLKtWLAKxCbiYO3VcS0pCc1ats/OVjvBZZYjqYhiXkxNTT4iQf kImY0rfBYgfb6yQ== X-Received: from wmqo22.prod.google.com ([2002:a05:600c:4fd6:b0:48e:5bb9:e1a4]) (user=smostafa job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:34c9:b0:48f:eb8b:9980 with SMTP id 5b1f17b1804b1-490360e8403mr44838825e9.30.1779368711854; Thu, 21 May 2026 06:05:11 -0700 (PDT) Date: Thu, 21 May 2026 13:05:03 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.54.0.669.g59709faab0-goog Message-ID: <20260521130503.4103369-1-smostafa@google.com> Subject: [PATCH] irqchip/gic-v4: Harden against bogus command line From: Mostafa Saleh To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: maz@kernel.org, tglx@kernel.org, Mostafa Saleh Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When accidentally setting =E2=80=9Ckvm-arm.vgic_v4_enable=3D1=E2=80=9D on t= he wrong setup that has no MSI controller device tree node (it exists but not used) and GICv4, it caused a panic as =E2=80=9Cgic_domain=E2=80=9D is N= ULL and the kernel attempted to access its ops. Originally, I hit this on an older kernel, but was able to reproduce it on upstream with Qemu by hacking this unreasonable setup. [ 33.145536] Unable to handle kernel NULL pointer dereference at virtual = address 0000000000000028 [ 33.145658] Mem abort info: [ 33.145751] ESR =3D 0x0000000096000006 ... [ 33.154057] CPU: 1 UID: 0 PID: 295 Comm: lkvm-static Not tainted 7.1.0-r= c4-ge3f15ad3970e #5 PREEMPT [ 33.156922] Hardware name: linux,dummy-virt (DT) [ 33.158780] pstate: 81402005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE= =3D--) [ 33.160340] pc : __irq_domain_instantiate+0x1d4/0x578 [ 33.162602] lr : __irq_domain_instantiate+0x1cc/0x578 Add a hardening check to avoid the NULL access, and fail the VM creation in that case. Signed-off-by: Mostafa Saleh --- drivers/irqchip/irq-gic-v4.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c index 8455b4a5fbb0..7e39f7eae85f 100644 --- a/drivers/irqchip/irq-gic-v4.c +++ b/drivers/irqchip/irq-gic-v4.c @@ -159,6 +159,9 @@ int its_alloc_vcpu_irqs(struct its_vm *vm) { int vpe_base_irq, i; =20 + if (!gic_domain) + return -EINVAL; + vm->fwnode =3D irq_domain_alloc_named_id_fwnode("GICv4-vpe", task_pid_nr(current)); if (!vm->fwnode) --=20 2.54.0.669.g59709faab0-goog