diff options
| author | Lin Ma | 2021-11-11 22:14:02 +0800 |
|---|---|---|
| committer | Jakub Kicinski | 2021-11-12 19:56:47 -0800 |
| commit | 81b1d548d00bcd028303c4f3150fa753b9b8aa71 (patch) | |
| tree | 3fa494df2325fcbdf209faa46ced6bcb33853dba | |
| parent | 66f4beaa6c1d28161f534471484b2daa2de1dce0 (diff) | |
hamradio: remove needs_free_netdev to avoid UAF
The former patch "defer 6pack kfree after unregister_netdev" reorders
the kfree of two buffer after the unregister_netdev to prevent the race
condition. It also adds free_netdev() function in sixpack_close(), which
is a direct copy from the similar code in mkiss_close().
However, in sixpack driver, the flag needs_free_netdev is set to true in
sp_setup(), hence the unregister_netdev() will free the netdev
automatically. Therefore, as the sp is netdev_priv, use-after-free
occurs.
This patch removes the needs_free_netdev = true and just let the
free_netdev to finish this deallocation task.
Fixes: 0b9111922b1f ("hamradio: defer 6pack kfree after unregister_netdev")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Link: https://lore.kernel.org/r/20211111141402.7551-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/hamradio/6pack.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c index bfdf89e54752..8a19a06b505d 100644 --- a/drivers/net/hamradio/6pack.c +++ b/drivers/net/hamradio/6pack.c @@ -306,7 +306,6 @@ static void sp_setup(struct net_device *dev) { /* Finish setting up the DEVICE info. */ dev->netdev_ops = &sp_netdev_ops; - dev->needs_free_netdev = true; dev->mtu = SIXP_MTU; dev->hard_header_len = AX25_MAX_HEADER_LEN; dev->header_ops = &ax25_header_ops; |