[PATCH] wireless/nl80211.c: fix uninitialized variable

[PATCH] wireless/nl80211.c: fix uninitialized variable

[Alaa Emad]

Reported-by: syzbot+72b99dcf4607e8c770f3@syzkaller.appspotmail.com
Signed-off-by: Alaa Emad <alaaemadhossney.ae@gmail.com>
---
 net/wireless/nl80211.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 775d0c4d86c3..b87ab67ad33d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -210,7 +210,7 @@ static int validate_beacon_head(const struct nlattr *attr,
 	const struct element *elem;
 	const struct ieee80211_mgmt *mgmt = (void *)data;
 	bool s1g_bcn = ieee80211_is_s1g_beacon(mgmt->frame_control);
-	unsigned int fixedlen, hdrlen;
+	unsigned int fixedlen = 0, hdrlen;
 
 	if (s1g_bcn) {
 		fixedlen = offsetof(struct ieee80211_ext,
-- 
2.25.1

Re: [PATCH] wireless/nl80211.c: fix uninitialized variable

[Greg KH]

On Mon, Mar 29, 2021 at 06:30:36PM +0200, Alaa Emad wrote:
> Reported-by: syzbot+72b99dcf4607e8c770f3@syzkaller.appspotmail.com
> Signed-off-by: Alaa Emad <alaaemadhossney.ae@gmail.com>

You need to provide some changelog text here, I know I can not take
patches without that, maybe the wireless maintainer is more flexible :)

thanks,

greg k-h

Re: [PATCH] wireless/nl80211.c: fix uninitialized variable

[Greg KH]

On Mon, Mar 29, 2021 at 08:41:38PM +0200, Alaa Emad wrote:
> On Mon, 29 Mar 2021 at 20:20, Greg KH <gregkh@linuxfoundation.org> wrote:
> 
> > On Mon, Mar 29, 2021 at 06:30:36PM +0200, Alaa Emad wrote:
> > > Reported-by: syzbot+72b99dcf4607e8c770f3@syzkaller.appspotmail.com
> > > Signed-off-by: Alaa Emad <alaaemadhossney.ae@gmail.com>
> >
> > You need to provide some changelog text here, I know I can not take
> > patches without that, maybe the wireless maintainer is more flexible :)
> >
>  you mean explain what i did , right?

Yes, explain why this change is needed.

thanks,

greg k-h

Re: [PATCH] wireless/nl80211.c: fix uninitialized variable

[Pavel Skripkin]

Hi!

On Tue, 2021-03-30 at 14:42 +0200, Alaa Emad wrote:
> 
> 
> On Mon, 29 Mar 2021 at 20:58, Greg KH <gregkh@linuxfoundation.org>
> wrote:
> > On Mon, Mar 29, 2021 at 08:41:38PM +0200, Alaa Emad wrote:
> > > On Mon, 29 Mar 2021 at 20:20, Greg KH <gregkh@linuxfoundation.org>
> > wrote:
> > > 
> > > > On Mon, Mar 29, 2021 at 06:30:36PM +0200, Alaa Emad wrote:
> > > > > Reported-by:
> > syzbot+72b99dcf4607e8c770f3@syzkaller.appspotmail.com
> > > > > Signed-off-by: Alaa Emad <alaaemadhossney.ae@gmail.com>
> > > > 
> > > > You need to provide some changelog text here, I know I can not
> > take
> > > > patches without that, maybe the wireless maintainer is more
> > flexible :)
> > > > 
> > >   you mean explain what i did , right?
> > 
> > Yes, explain why this change is needed.
> > 
> 
> 
>   
>   This change fix  KMSAN uninit-value in net/wireless/nl80211.c:225 ,
> That because of `fixedlen` variable uninitialized. 
>    So I initialized it by zero because the code assigned value to it
> after that and doesn't depend on any stored value in it . 

You should add this message to the patch, not just write it to
maintainer.

I think, this link might be
useful https://www.kernel.org/doc/html/v4.17/process/submitting-patches.html

> > 
> > thanks,
> > 
> > greg k-h
> > 
> 
> 
> 
> Thanks ,
> Alaa
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> .

With regards,
Pavel Skripkin