netdev - Re: [PATCH net] net/sched: act_ife: fix recursive lock and idr leak

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

Date:   Tue, 19 Jun 2018 13:13:36 -0700
From:   Cong Wang <xiyou.wangcong@...il.com>
To:     Davide Caratti <dcaratti@...hat.com>
Cc:     Jamal Hadi Salim <jhs@...atatu.com>,
        "David S. Miller" <davem@...emloft.net>,
        Linux Kernel Network Developers <netdev@...r.kernel.org>
Subject: Re: [PATCH net] net/sched: act_ife: fix recursive lock and idr leak

On Tue, Jun 19, 2018 at 6:39 AM, Davide Caratti <dcaratti@...hat.com> wrote:
> a recursive lock warning [1] can be observed with the following script,
>
>  # $TC actions add action ife encode allow prio pass index 42
>  IFE type 0xED3E
>  # $TC actions replace action ife encode allow tcindex pass index 42
>
> in case the kernel was unable to run the last command (e.g. because of
> the impossibility to load 'act_meta_skbtcindex'). For a similar reason,
> the kernel can leak idr in the error path of tcf_ife_init(), because
> tcf_idr_release() is not called after successful idr reservation:
>
>  # $TC actions add action ife encode allow tcindex index 47
>  IFE type 0xED3E
>  RTNETLINK answers: No such file or directory
>  We have an error talking to the kernel
>  # $TC actions add action ife encode allow tcindex index 47
>  IFE type 0xED3E
>  RTNETLINK answers: No space left on device
>  We have an error talking to the kernel
>  # $TC actions add action ife encode use mark 7 type 0xfefe pass index 47
>  IFE type 0xFEFE
>  RTNETLINK answers: No space left on device
>  We have an error talking to the kernel
>
> Since tcfa_lock is already taken when the action is being edited, a call
> to tcf_idr_release() wrongly makes tcf_idr_cleanup() take the same lock
> again. On the other hand, tcf_idr_release() needs to be called in the
> error path of tcf_ife_init(), to undo the last tcf_idr_create() invocation.
> Fix both problems in tcf_ife_init().
> Since the cleanup() routine can now be called when ife->params is NULL,
> also add a NULL pointer check to avoid calling kfree_rcu(NULL, rcu).

Acked-by: Cong Wang <xiyou.wangcong@...il.com>