Commit b64dd3c5 authored by Marcel Hamer's avatar Marcel Hamer Committed by Lin Yujun
Browse files

wifi: brcmfmac: fix NULL pointer dereference in brcmf_txfinalize() 

stable inclusion
from stable-v6.6.78
commit 3877fc67bd3d5566cc12763bce39710ceb74a97d
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBPC5U
CVE: CVE-2025-21744

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3877fc67bd3d5566cc12763bce39710ceb74a97d



--------------------------------

commit 68abd0c4ebf24cd499841a488b97a6873d5efabb upstream.

On removal of the device or unloading of the kernel module a potential NULL
pointer dereference occurs.

The following sequence deletes the interface:

  brcmf_detach()
    brcmf_remove_interface()
      brcmf_del_if()

Inside the brcmf_del_if() function the drvr->if2bss[ifidx] is updated to
BRCMF_BSSIDX_INVALID (-1) if the bsscfgidx matches.

After brcmf_remove_interface() call the brcmf_proto_detach() function is
called providing the following sequence:

  brcmf_detach()
    brcmf_proto_detach()
      brcmf_proto_msgbuf_detach()
        brcmf_flowring_detach()
          brcmf_msgbuf_delete_flowring()
            brcmf_msgbuf_remove_flowring()
              brcmf_flowring_delete()
                brcmf_get_ifp()
                brcmf_txfinalize()

Since brcmf_get_ip() can and actually will return NULL in this case the
call to brcmf_txfinalize() will result in a NULL pointer dereference inside
brcmf_txfinalize() when trying to update ifp->ndev->stats.tx_errors.

This will only happen if a flowring still has an skb.

Although the NULL pointer dereference has only been seen when trying to
update the tx statistic, all other uses of the ifp pointer have been
guarded as well with an early return if ifp is NULL.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarMarcel Hamer <marcel.hamer@windriver.com>
Link: https://lore.kernel.org/all/b519e746-ddfd-421f-d897-7620d229e4b2@gmail.com/


Acked-by: default avatarArend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: default avatarKalle Valo <kvalo@kernel.org>
Link: https://patch.msgid.link/20250116132240.731039-1-marcel.hamer@windriver.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarLin Yujun <linyujun809@huawei.com>
parent 9d22d5b7

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

+5 −0
Original line number Diff line number Diff line
@@ -540,6 +540,11 @@ void brcmf_txfinalize(struct brcmf_if *ifp, struct sk_buff *txp, bool success) 
	struct ethhdr *eh;

	u16 type;



	if (!ifp) {

		brcmu_pkt_buf_free_skb(txp);

		return;

	}



	eh = (struct ethhdr *)(txp->data);

	type = ntohs(eh->h_proto);