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| author | Lin Ma <linma@zju.edu.cn> | 2021-11-11 17:14:02 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-20 10:34:04 +0300 |
| commit | 9873fe0f3857c500fa21f92fe43b2a177e8de208 (patch) | |
| tree | ef62fe7424b52c7d8eafb2ad77b9cb713614a531 /drivers/net | |
| parent | c799c18a287e024e1c885da329aad8f719b255c3 (diff) | |
| download | linux-9873fe0f3857c500fa21f92fe43b2a177e8de208.tar.xz | |
hamradio: remove needs_free_netdev to avoid UAF
commit 81b1d548d00bcd028303c4f3150fa753b9b8aa71 upstream.
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>
Signed-off-by: Xu Jia <xujia39@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net')
| -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 167c300a5f80..36a9fbb70402 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; |