netdev - [PATCH v4] net/rose: Fix Use-After-Free in rose

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20231209100538.GA407321@v4bel-B760M-AORUS-ELITE-AX>
Date: Sat, 9 Dec 2023 05:05:38 -0500
From: Hyunwoo Kim <v4bel@...ori.io>
To: ralf@...ux-mips.org, edumazet@...gle.com
Cc: v4bel@...ori.io, imv4bel@...il.com, davem@...emloft.net,
	kuba@...nel.org, pabeni@...hat.com, linux-hams@...r.kernel.org,
	netdev@...r.kernel.org
Subject: [PATCH v4] net/rose: Fix Use-After-Free in rose_ioctl

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.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Hyunwoo Kim <v4bel@...ori.io>
---
v1 -> v2: Use sk->sk_receive_queue.lock instead of lock_sock.
v2 -> v3: Change spin_lock to spin_lock_irq
v3 -> v4: Delete old comments
---
 net/rose/af_rose.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index 0cc5a4e19900..ecb91ad4ce63 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1315,9 +1315,11 @@ static int rose_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 	case TIOCINQ: {
 		struct sk_buff *skb;
 		long amount = 0L;
-		/* These two are safe on a single CPU system as only user tasks fiddle here */
+
+		spin_lock_irq(&sk->sk_receive_queue.lock);
 		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
 			amount = skb->len;
+		spin_unlock_irq(&sk->sk_receive_queue.lock);
 		return put_user(amount, (unsigned int __user *) argp);
 	}
 
-- 
2.25.1