| Message ID | e5f98dc2-0305-491f-a860-71bbd1398a2f@kili.mountain (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 8fafac202d18230bb9926bda48e563fd2cce2a4f |
| Headers | show |
| Series | xen/pvcalls-back: fix double frees with pvcalls_new_active_socket() | expand |
On 03.05.23 17:11, Dan Carpenter wrote: > In the pvcalls_new_active_socket() function, most error paths call > pvcalls_back_release_active(fedata->dev, fedata, map) which calls > sock_release() on "sock". The bug is that the caller also frees sock. > > Fix this by making every error path in pvcalls_new_active_socket() > release the sock, and don't free it in the caller. > > Fixes: 5db4d286a8ef ("xen/pvcalls: implement connect command") > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Juergen Gross <jgross@suse.com> Juergen
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index 1f5219e12cc3..7beaf2c41fbb 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -325,8 +325,10 @@ static struct sock_mapping *pvcalls_new_active_socket( void *page; map = kzalloc(sizeof(*map), GFP_KERNEL); - if (map == NULL) + if (map == NULL) { + sock_release(sock); return NULL; + } map->fedata = fedata; map->sock = sock; @@ -418,10 +420,8 @@ static int pvcalls_back_connect(struct xenbus_device *dev, req->u.connect.ref, req->u.connect.evtchn, sock); - if (!map) { + if (!map) ret = -EFAULT; - sock_release(sock); - } out: rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); @@ -561,7 +561,6 @@ static void __pvcalls_back_accept(struct work_struct *work) sock); if (!map) { ret = -EFAULT; - sock_release(sock); goto out_error; }
In the pvcalls_new_active_socket() function, most error paths call pvcalls_back_release_active(fedata->dev, fedata, map) which calls sock_release() on "sock". The bug is that the caller also frees sock. Fix this by making every error path in pvcalls_new_active_socket() release the sock, and don't free it in the caller. Fixes: 5db4d286a8ef ("xen/pvcalls: implement connect command") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> --- drivers/xen/pvcalls-back.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)