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Commit dca2307e authored by Arend Van Spriel's avatar Arend Van Spriel Committed by Kalle Valo
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brcmfmac: fix double free upon register_netdevice() failure 



The function brcmf_net_attach() can only fail when register_netdevice()
fails. When this happens register_netdevice() calls priv_destructor, ie.
brcmf_cfg80211_free_netdev() freeing the vif instance. Also upon this
failure brcmf_net_attach() calls free_netdev(). However, callers are also
doing cleanup resulting in double free. In some places they need netdev
private space as it holds parameters to communicate with the device. So
we want to do the cleanup only in callers of brcmf_net_attach() by making
the following changes:

 - set priv_destructor after register_netdevice() succeeds.
 - remove call to free_netdev() in brcmf_net_attach().
 - call free_netdev() in brcmf_net_detach() for unregistered netdev.
 - add free_netdev() if brcmf_net_attach() fails for a created interface.

Fixes: cf124db5 ("net: Fix inconsistent teardown and release of private netdev state.")
Reviewed-by: default avatarHante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: default avatarPieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: default avatarFranky Lin <franky.lin@broadcom.com>
Signed-off-by: default avatarArend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
parent 593814d1

drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c

+1 −0
Original line number Diff line number Diff line
@@ -625,6 +625,7 @@ struct wireless_dev *brcmf_ap_add_vif(struct wiphy *wiphy, const char *name, 
	err = brcmf_net_attach(ifp, true);

	if (err) {

		brcmf_err("Registering netdevice failed\n");

		free_netdev(ifp->ndev);

		goto fail;

	}

drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c

+2 −3
Original line number Diff line number Diff line
@@ -485,13 +485,13 @@ int brcmf_net_attach(struct brcmf_if *ifp, bool rtnl_locked) 
		goto fail;

	}



	ndev->priv_destructor = brcmf_cfg80211_free_netdev;

	brcmf_dbg(INFO, "%s: Broadcom Dongle Host Driver\n", ndev->name);

	return 0;



fail:

	drvr->iflist[ifp->bsscfgidx] = NULL;

	ndev->netdev_ops = NULL;

	free_netdev(ndev);

	return -EBADE;

}
@@ -504,6 +504,7 @@ static void brcmf_net_detach(struct net_device *ndev, bool rtnl_locked) 
			unregister_netdev(ndev);

	} else {

		brcmf_cfg80211_free_netdev(ndev);

		free_netdev(ndev);

	}

}
@@ -580,7 +581,6 @@ static int brcmf_net_p2p_attach(struct brcmf_if *ifp) 
fail:

	ifp->drvr->iflist[ifp->bsscfgidx] = NULL;

	ndev->netdev_ops = NULL;

	free_netdev(ndev);

	return -EBADE;

}
@@ -626,7 +626,6 @@ struct brcmf_if *brcmf_add_if(struct brcmf_pub *drvr, s32 bsscfgidx, s32 ifidx, 
			return ERR_PTR(-ENOMEM);



		ndev->needs_free_netdev = true;

		ndev->priv_destructor = brcmf_cfg80211_free_netdev;

		ifp = netdev_priv(ndev);

		ifp->ndev = ndev;

		/* store mapping ifidx to bsscfgidx */

drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c

+1 −0
Original line number Diff line number Diff line
@@ -2208,6 +2208,7 @@ struct wireless_dev *brcmf_p2p_add_vif(struct wiphy *wiphy, const char *name, 
	err = brcmf_net_attach(ifp, true);

	if (err) {

		brcmf_err("Registering netdevice failed\n");

		free_netdev(ifp->ndev);

		goto fail;

	}