From: Pan Bian <bianpan2016@163.com> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Himadri Pandya <himadri18.07@gmail.com>, YueHaibing <yuehaibing@huawei.com>, Colin Ian King <colin.king@canonical.com> Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Pan Bian <bianpan2016@163.com> Subject: [PATCH] staging: rtl8192e: fix potential use after free Date: Tue, 5 Nov 2019 22:49:11 +0800 [thread overview] Message-ID: <1572965351-6745-1-git-send-email-bianpan2016@163.com> (raw) The variable skb is released via kfree_skb() when the return value of _rtl92e_tx is not zero. However, after that, skb is accessed again to read its length, which may result in a use after free bug. This patch fixes the bug by moving the release operation to where skb is never used later. Signed-off-by: Pan Bian <bianpan2016@163.com> --- drivers/staging/rtl8192e/rtl8192e/rtl_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/staging/rtl8192e/rtl8192e/rtl_core.c b/drivers/staging/rtl8192e/rtl8192e/rtl_core.c index f932cb15e4e5..cdcb22f96ed9 100644 --- a/drivers/staging/rtl8192e/rtl8192e/rtl_core.c +++ b/drivers/staging/rtl8192e/rtl8192e/rtl_core.c @@ -1616,14 +1616,15 @@ static void _rtl92e_hard_data_xmit(struct sk_buff *skb, struct net_device *dev, memcpy((unsigned char *)(skb->cb), &dev, sizeof(dev)); skb_push(skb, priv->rtllib->tx_headroom); ret = _rtl92e_tx(dev, skb); - if (ret != 0) - kfree_skb(skb); if (queue_index != MGNT_QUEUE) { priv->rtllib->stats.tx_bytes += (skb->len - priv->rtllib->tx_headroom); priv->rtllib->stats.tx_packets++; } + + if (ret != 0) + kfree_skb(skb); } static int _rtl92e_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Pan Bian <bianpan2016@163.com> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Himadri Pandya <himadri18.07@gmail.com>, YueHaibing <yuehaibing@huawei.com>, Colin Ian King <colin.king@canonical.com> Cc: devel@driverdev.osuosl.org, Pan Bian <bianpan2016@163.com>, linux-kernel@vger.kernel.org Subject: [PATCH] staging: rtl8192e: fix potential use after free Date: Tue, 5 Nov 2019 22:49:11 +0800 [thread overview] Message-ID: <1572965351-6745-1-git-send-email-bianpan2016@163.com> (raw) The variable skb is released via kfree_skb() when the return value of _rtl92e_tx is not zero. However, after that, skb is accessed again to read its length, which may result in a use after free bug. This patch fixes the bug by moving the release operation to where skb is never used later. Signed-off-by: Pan Bian <bianpan2016@163.com> --- drivers/staging/rtl8192e/rtl8192e/rtl_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/staging/rtl8192e/rtl8192e/rtl_core.c b/drivers/staging/rtl8192e/rtl8192e/rtl_core.c index f932cb15e4e5..cdcb22f96ed9 100644 --- a/drivers/staging/rtl8192e/rtl8192e/rtl_core.c +++ b/drivers/staging/rtl8192e/rtl8192e/rtl_core.c @@ -1616,14 +1616,15 @@ static void _rtl92e_hard_data_xmit(struct sk_buff *skb, struct net_device *dev, memcpy((unsigned char *)(skb->cb), &dev, sizeof(dev)); skb_push(skb, priv->rtllib->tx_headroom); ret = _rtl92e_tx(dev, skb); - if (ret != 0) - kfree_skb(skb); if (queue_index != MGNT_QUEUE) { priv->rtllib->stats.tx_bytes += (skb->len - priv->rtllib->tx_headroom); priv->rtllib->stats.tx_packets++; } + + if (ret != 0) + kfree_skb(skb); } static int _rtl92e_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) -- 2.7.4 _______________________________________________ devel mailing list devel@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
next reply other threads:[~2019-11-05 14:49 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-05 14:49 Pan Bian [this message] 2019-11-05 14:49 ` [PATCH] staging: rtl8192e: fix potential use after free Pan Bian 2019-11-05 14:58 ` Dan Carpenter 2019-11-05 14:58 ` Dan Carpenter
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