Patch "Bluetooth: RFCOMM: Fix not validating setsockopt user input" has been added to the 6.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    Bluetooth: RFCOMM: Fix not validating setsockopt user input

to the 6.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     bluetooth-rfcomm-fix-not-validating-setsockopt-user-.patch
and it can be found in the queue-6.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 0bf64134f75715972040cd9bd0434cf982e7982b
Author: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Date:   Fri Apr 5 15:43:45 2024 -0400

    Bluetooth: RFCOMM: Fix not validating setsockopt user input
    
    [ Upstream commit a97de7bff13b1cc825c1b1344eaed8d6c2d3e695 ]
    
    syzbot reported rfcomm_sock_setsockopt_old() is copying data without
    checking user input length.
    
    BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset
    include/linux/sockptr.h:49 [inline]
    BUG: KASAN: slab-out-of-bounds in copy_from_sockptr
    include/linux/sockptr.h:55 [inline]
    BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt_old
    net/bluetooth/rfcomm/sock.c:632 [inline]
    BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt+0x893/0xa70
    net/bluetooth/rfcomm/sock.c:673
    Read of size 4 at addr ffff8880209a8bc3 by task syz-executor632/5064
    
    Fixes: 9f2c8a03fbb3 ("Bluetooth: Replace RFCOMM link mode with security level")
    Fixes: bb23c0ab8246 ("Bluetooth: Add support for deferring RFCOMM connection setup")
    Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
    Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
    Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index b54e8a530f55a..29aa07e9db9d7 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -629,7 +629,7 @@ static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname,
 
 	switch (optname) {
 	case RFCOMM_LM:
-		if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
+		if (bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen)) {
 			err = -EFAULT;
 			break;
 		}
@@ -664,7 +664,6 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,
 	struct sock *sk = sock->sk;
 	struct bt_security sec;
 	int err = 0;
-	size_t len;
 	u32 opt;
 
 	BT_DBG("sk %p", sk);
@@ -686,11 +685,9 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,
 
 		sec.level = BT_SECURITY_LOW;
 
-		len = min_t(unsigned int, sizeof(sec), optlen);
-		if (copy_from_sockptr(&sec, optval, len)) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(&sec, sizeof(sec), optval, optlen);
+		if (err)
 			break;
-		}
 
 		if (sec.level > BT_SECURITY_HIGH) {
 			err = -EINVAL;
@@ -706,10 +703,9 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,
 			break;
 		}
 
-		if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen);
+		if (err)
 			break;
-		}
 
 		if (opt)
 			set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);