[PATCH 4.4 69/86] cw1200: Dont leak memory if krealloc failes

Greg Kroah-Hartman
2018-11-29T14:19:30Z

From: Johannes Thumshirn <jthumshirn@suse.de>

commit 9afdd6128c39f42398041bb2e017d8df0dcebcd1 upstream.

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 <jthumshirn@suse.de>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/cw1200/wsm.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

--- a/drivers/net/wireless/cw1200/wsm.c
+++ b/drivers/net/wireless/cw1200/wsm.c
@@ -1805,16 +1805,18 @@ static int wsm_buf_reserve(struct wsm_bu
{
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;
}