From: Andrew Morton <akpm@linux-foundation.org>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk,
rientjes@google.com, wilsons@start.ca, security@kernel.org,
kernel-hardening@lists.openwall.com
Subject: [kernel-hardening] Re: [PATCH v2] proc: fix a race in do_io_accounting()
Date: Tue, 5 Jul 2011 14:13:01 -0700 [thread overview]
Message-ID: <20110705141301.0d3594e0.akpm@linux-foundation.org> (raw)
In-Reply-To: <20110704201339.GA5645@albatros>
<wakes up>
On Tue, 5 Jul 2011 00:13:39 +0400
Vasiliy Kulikov <segoon@openwall.com> wrote:
> There is a ptrace_may_access() check in do_io_accounting() to prevent
> gathering information of setuid'ed and similar binaries. However, there
> is a race against execve(). Holding task->signal->cred_guard_mutex
> while gathering the information should protect against the race.
>
> The order of locking is similar to the one inside of
> ptrace_attach(): first goes cred_guard_mutex, then lock_task_sighand().
>
> v2 - use mutex_lock_killable() instead of mutex_lock().
>
> Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
> Cc: stable@kernel.org
If a patch is to be backported into -stable then its changelog had
better explain why such a thing is needed. This one doesn't.
Please provide a full description of the conseuqences of the bug. One
which will permit the -stable maintainers to understand why they're
merging the patch, and one which will help distribution maintainers
decide whether they want to merge it as well.
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk,
rientjes@google.com, wilsons@start.ca, security@kernel.org,
kernel-hardening@lists.openwall.com
Subject: Re: [PATCH v2] proc: fix a race in do_io_accounting()
Date: Tue, 5 Jul 2011 14:13:01 -0700 [thread overview]
Message-ID: <20110705141301.0d3594e0.akpm@linux-foundation.org> (raw)
In-Reply-To: <20110704201339.GA5645@albatros>
<wakes up>
On Tue, 5 Jul 2011 00:13:39 +0400
Vasiliy Kulikov <segoon@openwall.com> wrote:
> There is a ptrace_may_access() check in do_io_accounting() to prevent
> gathering information of setuid'ed and similar binaries. However, there
> is a race against execve(). Holding task->signal->cred_guard_mutex
> while gathering the information should protect against the race.
>
> The order of locking is similar to the one inside of
> ptrace_attach(): first goes cred_guard_mutex, then lock_task_sighand().
>
> v2 - use mutex_lock_killable() instead of mutex_lock().
>
> Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
> Cc: stable@kernel.org
If a patch is to be backported into -stable then its changelog had
better explain why such a thing is needed. This one doesn't.
Please provide a full description of the conseuqences of the bug. One
which will permit the -stable maintainers to understand why they're
merging the patch, and one which will help distribution maintainers
decide whether they want to merge it as well.
next prev parent reply other threads:[~2011-07-05 21:13 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-03 10:39 [kernel-hardening] [PATCH] proc: fix a race in do_io_accounting() Vasiliy Kulikov
2011-07-03 10:39 ` Vasiliy Kulikov
2011-07-03 19:24 ` [kernel-hardening] " Linus Torvalds
2011-07-03 19:24 ` Linus Torvalds
2011-07-03 20:01 ` [kernel-hardening] " Vasiliy Kulikov
2011-07-03 20:01 ` Vasiliy Kulikov
2011-07-04 20:13 ` [kernel-hardening] [PATCH v2] " Vasiliy Kulikov
2011-07-04 20:13 ` Vasiliy Kulikov
2011-07-05 21:13 ` Andrew Morton [this message]
2011-07-05 21:13 ` Andrew Morton
2011-07-06 16:34 ` [kernel-hardening] [PATCH v3] " Vasiliy Kulikov
2011-07-06 16:34 ` Vasiliy Kulikov
2011-07-15 6:38 ` [kernel-hardening] " Vasiliy Kulikov
2011-07-15 6:38 ` Vasiliy Kulikov
2011-07-15 16:14 ` [kernel-hardening] " Linus Torvalds
2011-07-15 16:14 ` Linus Torvalds
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