From patchwork Tue Feb 27 00:54:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 13573030 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E2EAE15CB; Tue, 27 Feb 2024 00:55:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708995306; cv=none; b=maMytcflrA7LcBeQhyEBjyps3/msuuFN3nFbS+o10ni2D0rYjcqAGRhczPMkMFfQZI9f+B6/56hBQ6beXmiKIj8r4XyUKtMzq31H66TGOCC2TYzZeIfv9tHznaKS+lje8V+0WRlflNsCgEgwHPlnYJ2aWEFHnPn+eYKSEYz6hg4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708995306; c=relaxed/simple; bh=ss8VwZn4a5t6mx/5BWpuy9l0XPO5ja2ql+oKmi1naJg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=gn6I7LgSjY85MxzJxaPJyXEYVgzlJRHGuqG5EmW2WHWODkrlxelDIPiKHCWdtV+XgvVbHUIMFm/g/CsL4KR/s8YxWWolFiqQwvKsAvpE89pCYhWTswp5lDhxmAj56yFqUy9A71vrt3FBAbwyuMWPCQuEqf05YEfkVRuMHlit/y8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=g3EtBjPw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="g3EtBjPw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 965FDC433F1; Tue, 27 Feb 2024 00:55:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708995305; bh=ss8VwZn4a5t6mx/5BWpuy9l0XPO5ja2ql+oKmi1naJg=; h=From:Date:Subject:To:Cc:From; b=g3EtBjPw9BkQf1JaTfipWe2RSvJN+FjTxpHl8mmlomdAhvj/4Y1I2Le0T24DZkNBe 7uk3pXy0MTVHwvHFRzs7JSSUUMXDH+i/wTKyexaAn7wxlGJ9lZJUIPpG8WJoXBdSHu vhIPL0hEmbbIZNyJ/JjsIA7RU/VU2g3JeYNcwTE4wxGeT48sRMl0ehhNGoXR6X72ar 0aYHU/vZuK+gX59lsGbNcbxnk8hf0csOhnV2Zafj1V3Y+vYn7hnYbqiWFwCdXRP0BK NXHQOWaDKZJdDbpD35VdzgUQ7AT1fsONlOzG9uJFec+F3sCRXHnOR+v8MmoIrC2u/a MLXdWgVVYvKIg== From: Nathan Chancellor Date: Mon, 26 Feb 2024 17:54:58 -0700 Subject: [PATCH] thermal: core: Move initial num_trips assignment before memcpy() Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240226-thermal-fix-fortify-panic-num_trips-v1-1-accc12a341d7@kernel.org> X-B4-Tracking: v=1; b=H4sIAOIy3WUC/x2N0QqDMAwAf0XyvEBXO6H7lTFG5xINaC1pJ4r47 yt7PDjuDsikQhnuzQFKq2RZYoXrpYF+DHEglE9lsMY6Y22HZSSdw4QsG/KiRXjHFKL0GL/zq6i kjDf2znjHb9+1UEtJqer/y+N5nj++m9k2dQAAAA== To: rafael@kernel.org, daniel.lezcano@linaro.org Cc: rui.zhang@intel.com, lukasz.luba@arm.com, keescook@chromium.org, gustavoars@kernel.org, morbo@google.com, justinstitt@google.com, stanislaw.gruszka@linux.intel.com, linux-pm@vger.kernel.org, linux-hardening@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, Nathan Chancellor X-Mailer: b4 0.14-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1946; i=nathan@kernel.org; h=from:subject:message-id; bh=ss8VwZn4a5t6mx/5BWpuy9l0XPO5ja2ql+oKmi1naJg=; b=owGbwMvMwCUmm602sfCA1DTG02pJDKl3jV6EfCpn4bv2/K1+5c1nAcxxSgyTMxkc86IDc135G vZsYrjeUcrCIMbFICumyFL9WPW4oeGcs4w3Tk2CmcPKBDKEgYtTACYirsHwP07kle3h+3G7nt9R Xxc1u6p7a2rBnMfPf16Z5zkrX0R52ylGhrfmh1R3rCtTf/OTYcnvOQa/3ihM7Z07N39DYI9s/2H XDDYA X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 When booting a CONFIG_FORTIFY_SOURCE=y kernel compiled with a toolchain that supports __counted_by() (such as clang-18 and newer), there is a panic on boot: [ 2.913770] memcpy: detected buffer overflow: 72 byte write of buffer size 0 [ 2.920834] WARNING: CPU: 2 PID: 1 at lib/string_helpers.c:1027 __fortify_report+0x5c/0x74 ... [ 3.039208] Call trace: [ 3.041643] __fortify_report+0x5c/0x74 [ 3.045469] __fortify_panic+0x18/0x20 [ 3.049209] thermal_zone_device_register_with_trips+0x4c8/0x4f8 This panic occurs because trips is counted by num_trips but num_trips is assigned after the call to memcpy(), so the fortify checks think the buffer size is zero because tz was allocated with kzalloc(). Move the num_trips assignment before the memcpy() to resolve the panic and ensure that the fortify checks work properly. Fixes: 9b0a62758665 ("thermal: core: Store zone trips table in struct thermal_zone_device") Signed-off-by: Nathan Chancellor Reviewed-by: Kees Cook --- drivers/thermal/thermal_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: a85739c8c6894c3b9ff860e79e91db44cb59bd63 change-id: 20240226-thermal-fix-fortify-panic-num_trips-5f94094fb963 Best regards, diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index bb21f78b4bfa..1eabc8ebe27d 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -1354,8 +1354,8 @@ thermal_zone_device_register_with_trips(const char *type, tz->device.class = thermal_class; tz->devdata = devdata; - memcpy(tz->trips, trips, num_trips * sizeof(*trips)); tz->num_trips = num_trips; + memcpy(tz->trips, trips, num_trips * sizeof(*trips)); thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay); thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);