From: Simon Horman <simon.horman@corigine.com>
To: Eric Dumazet <edumazet@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
syzbot <syzkaller@googlegroups.com>,
Stephen Hemminger <stephen@networkplumber.org>,
Jamal Hadi Salim <jhs@mojatatu.com>
Subject: Re: [PATCH net] sch_netem: fix issues in netem_change() vs get_dist_table()
Date: Fri, 23 Jun 2023 09:54:42 +0200 [thread overview]
Message-ID: <ZJVPwoC09KWQeJpu@corigine.com> (raw)
In-Reply-To: <20230622181503.2327695-1-edumazet@google.com>
On Thu, Jun 22, 2023 at 06:15:03PM +0000, Eric Dumazet wrote:
> In blamed commit, I missed that get_dist_table() was allocating
> memory using GFP_KERNEL, and acquiring qdisc lock to perform
> the swap of newly allocated table with current one.
>
> In this patch, get_dist_table() is allocating memory and
> copy user data before we acquire the qdisc lock.
>
> Then we perform swap operations while being protected by the lock.
>
> Note that after this patch netem_change() no longer can do partial changes.
> If an error is returned, qdisc conf is left unchanged.
>
> Fixes: 2174a08db80d ("sch_netem: acquire qdisc lock in netem_change()")
> Reported-by: syzbot <syzkaller@googlegroups.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Stephen Hemminger <stephen@networkplumber.org>
> Cc: Jamal Hadi Salim <jhs@mojatatu.com>
> Cc: Simon Horman <simon.horman@corigine.com>
> ---
> net/sched/sch_netem.c | 59 ++++++++++++++++++-------------------------
> 1 file changed, 25 insertions(+), 34 deletions(-)
Reviewed-by: Simon Horman <simon.horman@corigine.com>
next prev parent reply other threads:[~2023-06-23 7:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-22 18:15 [PATCH net] sch_netem: fix issues in netem_change() vs get_dist_table() Eric Dumazet
2023-06-22 18:56 ` Jamal Hadi Salim
2023-06-23 7:54 ` Simon Horman [this message]
2023-06-24 22:20 ` patchwork-bot+netdevbpf
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