net: bridge: fix ioctl old_deviceless bridge argument

Commit ad2f99a ("net: bridge: move bridge ioctls out of .ndo_do_ioctl") changed the source of the argument copy in bridge's old_deviceless() from args[1] (user ptr to device name) to uarg (ptr to ioctl arguments) causing wrong device name to be used. Example (broken, bridge exists but is up): $ brctl delbr bridge bridge bridge doesn't exist; can't delete it Example (working): $ brctl delbr bridge bridge bridge is still up; can't delete it Fixes: ad2f99a ("net: bridge: move bridge ioctls out of .ndo_do_ioctl") Signed-off-by: Nikolay Aleksandrov <[email protected]> Signed-off-by: David S. Miller <[email protected]>
bignaux · Aug 5, 2021 · cbd7ad2 · cbd7ad2
1 parent 893b195
commit cbd7ad2
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c
@@ -351,7 +351,7 @@ static int old_deviceless(struct net *net, void __user *uarg)
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			return -EPERM;
 
-		if (copy_from_user(buf, uarg, IFNAMSIZ))
+		if (copy_from_user(buf, (void __user *)args[1], IFNAMSIZ))
 			return -EFAULT;
 
 		buf[IFNAMSIZ-1] = 0;