From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Thumshirn Subject: [PATCH v2] cw1200: Don't leak memory if krealloc failes Date: Fri, 30 Sep 2016 14:39:17 +0200 Message-ID: <1475239157-16448-1-git-send-email-jthumshirn@suse.de> Cc: linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Johannes Thumshirn , Johannes Berg To: Solomon Peachy , Kalle Valo Return-path: Sender: linux-wireless-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org The call to krealloc() in wsm_buf_reserve() directly assigns the newly returned memory to buf->begin. This is all fine except when krealloc() failes we loose the ability to free the old memory pointed to by buf->begin. If we just create a temporary variable to assign memory to and assign the memory to it we can mitigate the memory leak. Signed-off-by: Johannes Thumshirn Cc: Johannes Berg --- drivers/net/wireless/st/cw1200/wsm.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) Changes from v1: * Do the correct check for a failed re-allocation (Johannes Berg) diff --git a/drivers/net/wireless/st/cw1200/wsm.c b/drivers/net/wireless/st/cw1200/wsm.c index 680d60e..ffb245e 100644 --- a/drivers/net/wireless/st/cw1200/wsm.c +++ b/drivers/net/wireless/st/cw1200/wsm.c @@ -1807,16 +1807,18 @@ static int wsm_buf_reserve(struct wsm_buf *buf, size_t extra_size) { size_t pos = buf->data - buf->begin; size_t size = pos + extra_size; + u8 *tmp; size = round_up(size, FWLOAD_BLOCK_SIZE); - buf->begin = krealloc(buf->begin, size, GFP_KERNEL | GFP_DMA); - if (buf->begin) { - buf->data = &buf->begin[pos]; - buf->end = &buf->begin[size]; - return 0; - } else { - buf->end = buf->data = buf->begin; + tmp = krealloc(buf->begin, size, GFP_KERNEL | GFP_DMA); + if (!tmp) { + wsm_buf_deinit(buf); return -ENOMEM; } + + buf->begin = tmp; + buf->data = &buf->begin[pos]; + buf->end = &buf->begin[size]; + return 0; } -- 1.8.5.6