linux-kernel - Re: [PATCH] chcr_ktls: add a defensive NULL check to prevent a possible null-pointer dereference in chcr_ktls_dev

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CADm8TekXPCwfYpiTUJuh6F6Uy3db-2rUzG900SJPz5Pad_dwrg@mail.gmail.com>
Date: Mon, 12 Jan 2026 01:25:29 +0800
From: Tuo Li <islituo@...il.com>
To: Jakub Kicinski <kuba@...nel.org>
Cc: ayush.sawal@...lsio.com, andrew+netdev@...n.ch, davem@...emloft.net, 
	edumazet@...gle.com, pabeni@...hat.com, kernelxing@...cent.com, 
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] chcr_ktls: add a defensive NULL check to prevent a
 possible null-pointer dereference in chcr_ktls_dev_del()

Hi Jakub

On Fri, Jan 9, 2026 at 9:53 AM Jakub Kicinski <kuba@...nel.org> wrote:
>
> On Tue,  6 Jan 2026 20:33:02 +0800 Tuo Li wrote:
> > In this function, u_ctx is guarded by an if statement, which indicates that
> > it may be NULL:
> >
> >   u_ctx = tx_info->adap->uld[CXGB4_ULD_KTLS].handle;
> >   if (u_ctx && u_ctx->detach)
> >     return;
> >
> > Consequently, a potential null-pointer dereference may occur when
> > tx_info->tid != -1, as shown below:
> >
> >   if (tx_info->tid != -1) {
> >     ...
> >     xa_erase(&u_ctx->tid_list, tx_info->tid);
> >   }
> >
> > Therefore, add a defensive NULL check to prevent this issue.
>
> There seems to be no locking here.
> It'd take much more to make this code safe, sprinking random ifs
> here and there seem like a waste of time.

Thanks for pointing this out.

Given the lack of proper locking here, I'd rather drop this patch than add
ad-hoc NULL checks.

Thanks for the review,
Tuo