Commit 7a9461ca authored by Dan Carpenter's avatar Dan Carpenter Committed by ZhangPeng
Browse files

mISDN: Fix a use after free in hfcmulti_tx() 

stable inclusion
from stable-v6.6.44
commit ddc79556641ee070d36be0de4a1f0a16a71f1fc7
bugzilla: https://gitee.com/openeuler/kernel/issues/IAHMJO

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ddc79556641ee070d36be0de4a1f0a16a71f1fc7



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

[ Upstream commit 61ab751451f5ebd0b98e02276a44e23a10110402 ]

Don't dereference *sp after calling dev_kfree_skb(*sp).

Fixes: af69fb3a ("Add mISDN HFC multiport driver")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/8be65f5a-c2dd-4ba0-8a10-bfe5980b8cfb@stanley.mountain


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
parent a9bfdde7

drivers/isdn/hardware/mISDN/hfcmulti.c

+4 −3
Original line number Diff line number Diff line
@@ -1900,7 +1900,7 @@ hfcmulti_dtmf(struct hfc_multi *hc) 
static void

hfcmulti_tx(struct hfc_multi *hc, int ch)

{

	int i, ii, temp, len = 0;

	int i, ii, temp, tmp_len, len = 0;

	int Zspace, z1, z2; /* must be int for calculation */

	int Fspace, f1, f2;

	u_char *d;
@@ -2121,14 +2121,15 @@ hfcmulti_tx(struct hfc_multi *hc, int ch) 
		HFC_wait_nodebug(hc);

	}



	tmp_len = (*sp)->len;

	dev_kfree_skb(*sp);

	/* check for next frame */

	if (bch && get_next_bframe(bch)) {

		len = (*sp)->len;

		len = tmp_len;

		goto next_frame;

	}

	if (dch && get_next_dframe(dch)) {

		len = (*sp)->len;

		len = tmp_len;

		goto next_frame;

	}