[PATCH v2] net/rose: Fix Use-After-Free in rose_ioctl
From: Hyunwoo Kim <hidden>
Date: 2023-12-06 04:13:38
Also in:
linux-hams
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Because rose_ioctl() accesses sk->sk_receive_queue without holding a sk->sk_receive_queue.lock, it can cause a race with rose_accept(). A use-after-free for skb occurs with the following flow.
rose_ioctl() -> skb_peek()
rose_accept() -> skb_dequeue() -> kfree_skb()
Add sk->sk_receive_queue.lock to rose_ioctl() to fix this issue. Signed-off-by: Hyunwoo Kim <redacted> --- v1 -> v2: Use sk->sk_receive_queue.lock instead of lock_sock. --- net/rose/af_rose.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index 0cc5a4e19900..841c238de222 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c@@ -1316,8 +1316,10 @@ static int rose_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) struct sk_buff *skb; long amount = 0L; /* These two are safe on a single CPU system as only user tasks fiddle here */ + spin_lock(&sk->sk_receive_queue.lock); if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) amount = skb->len; + spin_unlock(&sk->sk_receive_queue.lock); return put_user(amount, (unsigned int __user *) argp); }
--
2.25.1