Return-Path: From: Szymon Janc To: Atul Rai Cc: linux-bluetooth@vger.kernel.org, sachin.dev@samsung.com Subject: Re: [PATCH v2] android/client: Fix memory leak while using realloc() Date: Mon, 27 Jul 2015 21:18:25 +0200 Message-ID: <2255750.trinXVBJIG@leonov> In-Reply-To: <1437970480-2619-1-git-send-email-a.rai@samsung.com> References: <1437970480-2619-1-git-send-email-a.rai@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Atul, On Monday 27 of July 2015 09:44:40 Atul Rai wrote: > While reallocating space to store additional "remote device set" using > realloc, if realloc() fails, the original block is left untouched but > reference to that block is lost as NULL is assigned to remote_devices. > The original block needs to be freed before return. > --- > android/client/if-bt.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/android/client/if-bt.c b/android/client/if-bt.c > index 4723024..34611b9 100644 > --- a/android/client/if-bt.c > +++ b/android/client/if-bt.c > @@ -119,9 +119,18 @@ void add_remote_device(const bt_bdaddr_t *addr) > /* Realloc space if needed */ > if (remote_devices_cnt >= remote_devices_capacity) { > remote_devices_capacity *= 2; > + bt_bdaddr_t *tmp; > + > + /* > + * Save reference to previously allocated memory block so that > + * it can be freed in case realloc fails. > + */ > + tmp = remote_devices; > + > remote_devices = realloc(remote_devices, sizeof(bt_bdaddr_t) * > remote_devices_capacity); > if (remote_devices == NULL) { > + free(tmp); > remote_devices_capacity = 0; > remote_devices_cnt = 0; > return; This doesn't compile cleanly: CC android/client/android_haltest-if-hf-client.o android/client/if-bt.c: In function ‘add_remote_device’: android/client/if-bt.c:122:3: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement] bt_bdaddr_t *tmp; ^ cc1: all warnings being treated as errors Makefile:6171: recipe for target 'android/client/android_haltest-if-bt.o' failed You can use ./boostrap-configure;make for testing patches as this enables extra compiler flags. -- BR Szymon Janc