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  PHC 
Open Source and information security mailing list archives
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:	Sat, 31 Jan 2015 20:45:02 -0800
From:	John Fastabend <>
CC:	David Miller <>,
Subject: Re: [PATCH net] net: sched: fix panic in rate estimators

On 01/31/2015 05:55 PM, David Miller wrote:
> From: Eric Dumazet <>
> Date: Thu, 29 Jan 2015 17:30:12 -0800
>> From: Eric Dumazet <>
>> Doing the following commands on a non idle network device
>> panics the box instantly, because cpu_bstats gets overwritten
>> by stats.
>> tc qdisc add dev eth0 root <your_favorite_qdisc>
>> ... some traffic (one packet is enough) ...
>> tc qdisc replace dev eth0 root est 1sec 4sec <your_favorite_qdisc>
>   ...
>> Lets play safe and not use an union : percpu 'pointers' are mostly read
>> anyway, and we have typically few qdiscs per host.
>> Signed-off-by: Eric Dumazet <>
>> Cc: John Fastabend <>
>> Fixes: 22e0f8b9322c ("net: sched: make bstats per cpu and estimator RCU safe")
> Applied and queued up for -stable, thanks Eric.

Thanks Eric, looks like my "replace" test scripts never sent traffic
before the replace call.

Also I haven't seen any RCU splats in awhile so I'll send out a patch
to drop the qdisc_lock on ing_filter shortly.

John Fastabend         Intel Corporation
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists