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 for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 11 Apr 2014 15:50:27 +0200
From:	Mateusz Guzik <>
To:	"Wang, Xiaoming" <>
Subject: Re: [PATCH] net: ipv4: current group_info should be put after using.

On Fri, Apr 11, 2014 at 10:53:21PM -0400, Wang, Xiaoming wrote:
> This is a typical refcount leak exploitable by unprivileged users.
> Current group_info had been got in ping_init_sock and
> group_info->usage increased. But the usage hasn't decreased
> anywhere in ping. This will make this group_info never freed.

The patch is fine, however I had a brainfart with my last sentence about
commit message, sorry for that.

group_info *can be freed* by malicious user while still being pointed to
by something, that's the biggest problem with refcount leaks, therefore
this message needs some reworking.

I think that discussion about various consequences of refcount leak in
commit message is not necessary.

how about:

Plug a group_info refcount leak in ping_init.

group_info is only needed during initialization and the code failed to
release the reference on exit.

While here move grabbing the reference to a place where it is actually


Please cc: me if you resend the patch.

Mateusz Guzik
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