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 0551A1F03DE; Wed, 25 Feb 2026 01:46:20 +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=1771983980; cv=none; b=kOgvCTjGP7IScwMXUPjkyF4A4bsq+vujyNE+F4Sxjqj2CSq4trshMzSMUQCaNT15dYYZIESgJ4AViwrEHjafAaMIVtCDMgr3sMZL98LhiObWlJIY24hhiRqvcn5rR47Jy/T6WpIU88kARyii6FHMkG8/EA54ClylfXwL1v5H16E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983980; c=relaxed/simple; bh=8pGfaeGwwh652BaELEftFaYIdSV7KGlO9CS9Os+Uv3k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Pi6Idhtn1n/rCd4vokW18DXGd/Omh92A0eydg+k5ny2UFHuxRpNPjHamKiDZKmPTLkLx5IIuilksKgRfLe3MhfxTncMEFxN9xZWS3n7g6ZcbM7QwASf4cj/t2C9srfKPJxWzjOvdeBsK8kIdjZjmfBa8nShiDmFmD0ZtVcwtfUA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Bu0BBeb8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Bu0BBeb8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8DE2C19423; Wed, 25 Feb 2026 01:46:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771983979; bh=8pGfaeGwwh652BaELEftFaYIdSV7KGlO9CS9Os+Uv3k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bu0BBeb8C0Ml1krZZt3Az5B2+9mmgkTh7aVU312qh3LWjY1j9S6bydx2wD1C2+Pug eK5Am6/gZlvQqthq4zsHPTRdIXOVaHaRAwbWGcY/fA/LuMBmdNWOCd4YuuPbrEh6+e jBMYIjWN0iw3ypM6CkiRbAF/ZO4/nxJB/dn6haCg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jean Delvare , Junrui Luo , Guenter Roeck , Sasha Levin Subject: [PATCH 6.18 232/641] Revert "hwmon: (ibmpex) fix use-after-free in high/low store" Date: Tue, 24 Feb 2026 17:19:18 -0800 Message-ID: <20260225012354.515723387@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260225012348.915798704@linuxfoundation.org> References: <20260225012348.915798704@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ 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 129f3a9e8fe96..228c5f6c6f383 100644 --- a/drivers/hwmon/ibmpex.c +++ b/drivers/hwmon/ibmpex.c @@ -277,9 +277,6 @@ 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; @@ -511,9 +508,6 @@ 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, &dev_attr_name.attr); @@ -527,7 +521,8 @@ 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