From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Juhl Subject: [PATCH] mem-leak fix for acpi_thermal_write_trip_points() Date: Sun, 14 May 2006 02:28:58 +0200 Message-ID: <200605140228.58460.jesper.juhl@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from nf-out-0910.google.com ([64.233.182.188]:23075 "EHLO nf-out-0910.google.com") by vger.kernel.org with ESMTP id S964828AbWENA2H (ORCPT ); Sat, 13 May 2006 20:28:07 -0400 Received: by nf-out-0910.google.com with SMTP id c31so192435nfb for ; Sat, 13 May 2006 17:28:06 -0700 (PDT) Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Andy Grover , Paul Diefenbaugh , Len Brown , linux-acpi@vger.kernel.org, Jesper Juhl There's a memory leak in drivers/acpi/thermal.c::acpi_thermal_write_trip_points() found by the Coverity checker as bug #1243 The problem is simply that if the allocation of 'active' fails, then we'll return from the function without freeing the memory previously allocated to 'limit_string'. One fix would have been the insertion of kfree(limit_string); just before the return_VALUE(-ENOMEM); call, but I chose a different fix. Except for this one return the function only has a single exit point at the end: label, and there it does proper cleanup of everything. So even though setting the return value (the 'count' variable) and jumping there results in a pointless kfree(NULL) call (since 'active' will be NULL), I thought this was a small price to pay for the bennefit of having just a single exit path for the function. Signed-off-by: Jesper Juhl --- drivers/acpi/thermal.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) --- linux-2.6.17-rc4-git2-orig/drivers/acpi/thermal.c 2006-03-20 06:53:29.000000000 +0100 +++ linux-2.6.17-rc4-git2/drivers/acpi/thermal.c 2006-05-14 02:18:30.000000000 +0200 @@ -942,8 +942,10 @@ acpi_thermal_write_trip_points(struct fi memset(limit_string, 0, ACPI_THERMAL_MAX_LIMIT_STR_LEN); active = kmalloc(ACPI_THERMAL_MAX_ACTIVE * sizeof(int), GFP_KERNEL); - if (!active) - return_VALUE(-ENOMEM); + if (!active) { + count = -ENOMEM; + goto end; + } if (!tz || (count > ACPI_THERMAL_MAX_LIMIT_STR_LEN - 1)) { ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid argument\n"));