[PATCH v3 06/28] do_mq_notify(): saner skb freeing on failures

Al Viro
2024-11-02T05:08:47Z

cleanup is convoluted enough as it is; it's easier to have early
failure outs do explicit kfree_skb(nc), rather than going to
contortions needed to reuse the cleanup from late failures.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
ipc/mqueue.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index fd05e3d4f7b6..48640a362637 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -1347,8 +1347,8 @@ static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification)
if (copy_from_user(nc->data,
notification->sigev_value.sival_ptr,
NOTIFY_COOKIE_LEN)) {
- ret = -EFAULT;
- goto free_skb;
+ kfree_skb(nc);
+ return -EFAULT;
}

/* TODO: add a header? */
@@ -1357,16 +1357,14 @@ static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification)
retry:
sock = netlink_getsockbyfd(notification->sigev_signo);
if (IS_ERR(sock)) {
- ret = PTR_ERR(sock);
- goto free_skb;
+ kfree_skb(nc);
+ return PTR_ERR(sock);
}

timeo = MAX_SCHEDULE_TIMEOUT;
ret = netlink_attachskb(sock, nc, &timeo, NULL);
- if (ret == 1) {
- sock = NULL;
+ if (ret == 1)
goto retry;
- }
if (ret)
return ret;
}
@@ -1425,10 +1423,6 @@ static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification)
out:
if (sock)
netlink_detachskb(sock, nc);
- else
-free_skb:
- dev_kfree_skb(nc);
-
return ret;
}

--
2.39.5