Re: [PATCH Linux-next] ioctl_linux: fix a potential NULL pointer dereference bug
From: Pavel Skripkin <hidden>
Date: 2021-08-23 19:35:02
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On 8/23/21 6:06 AM, cgel.zte@gmail.com wrote:
quoted hunk ↗ jump to hunk
From: xu xin <xu.xin16@zte.com.cn> The pointer might be NULL, but it is dereferenced. Reported-by: Zeal Robot <redacted> Signed-off-by: xu xin <xu.xin16@zte.com.cn> --- drivers/staging/r8188eu/os_dep/ioctl_linux.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)diff --git a/drivers/staging/r8188eu/os_dep/ioctl_linux.c b/drivers/staging/r8188eu/os_dep/ioctl_linux.c index a3e6d761e748..ce4ce9190f5f 100644 --- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c +++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c@@ -4389,7 +4389,8 @@ static int rtw_dbg_port(struct net_device *dev, pregpriv->rx_stbc = extra_arg; DBG_88E("set rx_stbc =%d\n", pregpriv->rx_stbc); } else { - DBG_88E("get rx_stbc =%d\n", pregpriv->rx_stbc); + if (pregpriv) + DBG_88E("get rx_stbc =%d\n", pregpriv->rx_stbc); } } break;@@ -4401,7 +4402,8 @@ static int rtw_dbg_port(struct net_device *dev, pregpriv->ampdu_enable = extra_arg; DBG_88E("set ampdu_enable =%d\n", pregpriv->ampdu_enable); } else { - DBG_88E("get ampdu_enable =%d\n", pregpriv->ampdu_enable); + if (pregpriv) + DBG_88E("get ampdu_enable =%d\n", pregpriv->ampdu_enable); } } break;
Hi, Xu! I can't see how pregpriv can be NULL: struct registry_priv *pregpriv = &padapter->registrypriv; It can be NULL in case of completely wrong padapter pointer, but I can't see how it's possible. Do you have a calltrace? I guess, your robot reported this, because there is useless check in same code block: if (pregpriv && (extra_arg == 0 || extra_arg == 1 || extra_arg == 2 || extra_arg == 3)) So, I think, "pregpriv &&" part should be removed, instead of adding 2 branches. Also, subject line should be "staging: r8118eu: <subject>". Thank you! With regards, Pavel Skripkin