From mboxrd@z Thu Jan 1 00:00:00 1970 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 CAAB7383C66 for ; Sat, 28 Feb 2026 18:08:31 +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=1772302111; cv=none; b=Yv83hG3HQTVpkSFo+pKciDe6DKo9FvW/HEa91+hRWG+kQR0EjfM6ansuE9Uy2A3Pusd7FxCrrz5zhQqrSO4PHrRNiiQ41JVSwS/GCJQxOrYp+N7TccR/cG4iNB0zxyYn40zej0biGk5/fzVGs/7pGFcMn57RIr7d2lrGLbBqGpc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302111; c=relaxed/simple; bh=5s0v9TgRKN3OUY+s/+/NIvaREAjrmowNgeaj65dVPEc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=I8nc85wi9wj/vDGGl87v/kFpn2LFeaHfkOok36DqhE+lvE0eBC34hIgfZ/ONB6J28kD0XwSfbIoDv73H0udVkxox5fKv8Pj4Oc1ED+1AQ+Pxyh+rB0Qs7dRs6SRuQmGm2sBjjF4OlYuEK++Zc0cVL0gWwq1oKGlXJj/qMLdoZ+o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eqRXUw50; 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="eqRXUw50" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25533C116D0; Sat, 28 Feb 2026 18:08:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302111; bh=5s0v9TgRKN3OUY+s/+/NIvaREAjrmowNgeaj65dVPEc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eqRXUw50x5MzsebHE4YJcDrD7GX5ke2ZagW20TlaUEimsGsItufqvC6Rfis8IIoBr xaaHuAF5OLCRK88/ljjp5xtwQ3T0SNt0ZeeqKRl4V1BsBwlFQQCYyiHPMhmbm7gjcU KZOm2LqKmEOC6ccMmbezJb4j0sKrREUhSPijPENfMm6FZ0YBEhOVP/AN8xog6m08aK j37pqkmWb3NQ8yFhAimYZsklU88OoX/diAnA791XxJGbLjIcQEUa4s59eJc3dPadrI i4l2JyeC7obtx+QSXrYUW3Pj3Hz8/oNgpONMnV7sdJpaTyky834Wmgha/1RJGrPRzZ y13ViNw/zBCOQ== From: Sasha Levin To: patches@lists.linux.dev Cc: Guenter Roeck , Jean Delvare , Junrui Luo , Sasha Levin Subject: [PATCH 6.6 100/283] Revert "hwmon: (ibmpex) fix use-after-free in high/low store" Date: Sat, 28 Feb 2026 13:04:02 -0500 Message-ID: <20260228180709.1583486-100-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228180709.1583486-1-sashal@kernel.org> References: <20260228180709.1583486-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Guenter Roeck [ Upstream commit 8bde3e395a85017f12af2b0ba5c3684f5af9c006 ] This reverts commit 6946c726c3f4c36f0f049e6f97e88c510b15f65d. Jean Delvare points out that the patch does not completely fix the reported problem, that it in fact introduces a (new) race condition, and that it may actually not be needed in the first place. Various AI reviews agree. Specific and relevant AI feedback: " This reordering sets the driver data to NULL before removing the sensor attributes in the loop below. ibmpex_show_sensor() retrieves this driver data via dev_get_drvdata() but does not check if it is NULL before dereferencing it to access data->sensors[]. If a userspace process reads a sensor file (like temp1_input) while this delete function is running, could it race with the dev_set_drvdata(..., NULL) call here and crash in ibmpex_show_sensor()? Would it be safer to keep the original order where device_remove_file() is called before clearing the driver data? device_remove_file() should wait for any active sysfs callbacks to complete, which might already prevent the use-after-free this patch intends to fix. " Revert the offending patch. If it can be shown that the originally reported alleged race condition does indeed exist, it can always be re-introduced with a complete fix. Reported-by: Jean Delvare Closes: https://lore.kernel.org/linux-hwmon/20260121095342.73e723cb@endymion/ Cc: Jean Delvare Cc: Junrui Luo Fixes: 6946c726c3f4 ("hwmon: (ibmpex) fix use-after-free in high/low store") Reviewed-by: Jean Delvare Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/ibmpex.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/hwmon/ibmpex.c b/drivers/hwmon/ibmpex.c index 40fff7e95ea1c..db066b3689187 100644 --- a/drivers/hwmon/ibmpex.c +++ b/drivers/hwmon/ibmpex.c @@ -282,9 +282,6 @@ static ssize_t ibmpex_high_low_store(struct device *dev, { struct ibmpex_bmc_data *data = dev_get_drvdata(dev); - if (!data) - return -ENODEV; - ibmpex_reset_high_low_data(data); return count; @@ -517,9 +514,6 @@ static void ibmpex_bmc_delete(struct ibmpex_bmc_data *data) { int i, j; - hwmon_device_unregister(data->hwmon_dev); - dev_set_drvdata(data->bmc_device, NULL); - device_remove_file(data->bmc_device, &sensor_dev_attr_reset_high_low.dev_attr); device_remove_file(data->bmc_device, &sensor_dev_attr_name.dev_attr); @@ -533,7 +527,8 @@ static void ibmpex_bmc_delete(struct ibmpex_bmc_data *data) } list_del(&data->list); - + dev_set_drvdata(data->bmc_device, NULL); + hwmon_device_unregister(data->hwmon_dev); ipmi_destroy_user(data->user); kfree(data->sensors); kfree(data); -- 2.51.0