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 AA73433F8B4; Tue, 25 Aug 2026 16:09:38 +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=1787674181; cv=none; b=GpNPgTGWtFz2eKaKioZY45cW671ssnrOd8yOc0686LmK2dVtSGGJ61HS73WBpHMOTCCuvUkq1VsXsaA3gqQtgiyoObEYaHMsltLrK2Ow2rb6ucy7paQNV/3/97J2w1fkjUzjlNZl7zU2vWh7t1i43icBxNK3i3Y89gzQzdYulbs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787674181; c=relaxed/simple; bh=15gsy5bdbwhpf9Ije7bM1yVmEc5O16tDCToJXmaEDKI=; h=From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type:Date; b=Tc7f8ab2yGcwRd4LgQCELebqPEvoBP27lFmgDnWRBroaH+/jt5VEsBG8Wi6EupdWlo4jRWF4gdSvEprKgQKUqrAXmIvdsElBbthHCqpLDZlGAo5OfSr32Wa3P/0vS4Oicp63JRol+xq9L4pi0EOEbtukgdnu0yLSnw/YewLqHv8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RSqU7RNp; 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="RSqU7RNp" Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 72A161F000E9; Tue, 25 Aug 2026 16:09:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787674177; bh=HsEQKxgCoRAngmSKNRX4u8BYNQTCdnaMB9VQlBfOhcM=; h=From:To:Cc:Subject:Date; b=RSqU7RNp1A5SMsyb34uxEbQmSnGbinyXC0ZEqhkYTwkwNIjVC5VnvqpVx5iDtp8pA 2EPAysUQaej8it6K7sTkoGikFkIhl4tF311sJ9I2+FnPwwbIz4SMhZdjxu+ATFW+jg jGBifmExLbTrkH5ISI92GYlQiOx8SBYS4MQv5VhjLB/Ac/HoqgjPcw36cqoksVC1gf A+/wWbpttFem+dIkUmcFWFcHATB/kHHCyYT0MMClGmUx2AXvsy6Lo77asjCKPgZoUp ul6edX2eBDcc8sSzmEMv0pg4e2cfPbO1OUciremBfK+Uitn1E6jk6K4co/0MSuEC2F AiE5XNZAsi14A== From: "syzbot" To: syzkaller-bugs@googlegroups.com, Marco Elver , "Yehezkel Bernat" , "Andreas Noever" , , "Mika Westerberg" Cc: linux-kernel@vger.kernel.org, syzbot@lists.linux.dev Subject: [PATCH] thunderbolt: Validate BAR 0 resource type and size Message-ID: <9e0d4fdc-4e1d-4195-80c0-7a70d34d1fc2@mail.kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Date: Tue, 25 Aug 2026 16:09:37 +0000 (UTC) From: Marco Elver The thunderbolt driver can crash with a page fault if it binds to an arbitrary PCI device (e.g., via sysfs driver_override) that has an I/O port BAR at index 0 instead of an MMIO BAR. The driver maps this BAR without validating its type or size. When it attempts to read a Thunderbolt register at a large offset, the resulting I/O port cookie overflows the reserved PIO space on x86. This causes the generic ioread32() function to misinterpret the out-of-bounds I/O port cookie as a valid MMIO virtual address, leading to a direct dereference of an unmapped physical-like address and a page fault: BUG: unable to handle page fault for address: 00000000000556c0 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page ... Call Trace: nhi_probe+0xcc/0x870 drivers/thunderbolt/nhi.c:1198 nhi_pci_probe+0x46b/0x580 drivers/thunderbolt/pci.c:479 local_pci_probe drivers/pci/pci-driver.c:332 [inline] pci_call_probe drivers/pci/pci-driver.c:394 [inline] __pci_device_probe drivers/pci/pci-driver.c:455 [inline] pci_device_probe+0x431/0xc90 drivers/pci/pci-driver.c:489 To fix this, add explicit validation in nhi_pci_probe() to ensure that BAR 0 is an MMIO resource and is large enough to contain all the NHI registers before attempting to map it. The NHI register space extends up to offset 0x39944 (REG_FW_STS), so checking for a minimum size of 0x40000 (256 KB) is appropriate. Fixes: 16603153666d ("thunderbolt: Add initial cactus ridge NHI support") Assisted-by: Gemini:gemini-3.7-flash Gemini:gemini-3.1-pro-preview syzbot Reported-by: syzbot+97999b836ee62ddb0181@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=97999b836ee62ddb0181 Link: https://syzkaller.appspot.com/ai_job?id=2570f821-2184-40c8-8bd7-344a30c18a13 Signed-off-by: Marco Elver --- diff --git a/drivers/thunderbolt/nhi_regs.h b/drivers/thunderbolt/nhi_regs.h index d6a197fab..1feb0bfb0 100644 --- a/drivers/thunderbolt/nhi_regs.h +++ b/drivers/thunderbolt/nhi_regs.h @@ -140,6 +140,9 @@ struct ring_desc { #define REG_FW_STS_ICM_EN_INVERT BIT(1) #define REG_FW_STS_ICM_EN BIT(0) +/* Minimum BAR size to contain NHI registers */ +#define NHI_MIN_BAR_SIZE 0x40000 + /* ICL NHI VSEC registers */ /* FW ready */ diff --git a/drivers/thunderbolt/pci.c b/drivers/thunderbolt/pci.c index bbd186c29..fa69e4609 100644 --- a/drivers/thunderbolt/pci.c +++ b/drivers/thunderbolt/pci.c @@ -466,6 +466,14 @@ static int nhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) nhi->dev = dev; nhi->ops = (const struct tb_nhi_ops *)id->driver_data ?: &pci_nhi_default_ops; + /* Ensure BAR 0 is an MMIO resource */ + if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) + return dev_err_probe(dev, -EINVAL, "BAR 0 is not an MMIO resource\n"); + + /* Ensure BAR 0 is large enough to contain the NHI registers */ + if (pci_resource_len(pdev, 0) < NHI_MIN_BAR_SIZE) + return dev_err_probe(dev, -EINVAL, "BAR 0 is too small\n"); + nhi->iobase = pcim_iomap_region(pdev, 0, "thunderbolt"); res = PTR_ERR_OR_ZERO(nhi->iobase); if (res) base-commit: 8d3ae59288f1e7d58d76558a6ee96d533bc5019f -- See https://goo.gle/syzbot-ai-patches for information about AI-generated patches. The person who has signed off on the patch is responsible for addressing comments. syzbot engineers can be reached at syzkaller@googlegroups.com.