From: "Schaufler, Casey" <casey.schaufler@intel.com>
To: Jiri Kosina <jikos@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
"Josh Poimboeuf" <jpoimboe@redhat.com>,
Andrea Arcangeli <aarcange@redhat.com>,
"Woodhouse, David" <dwmw@amazon.co.uk>,
Andi Kleen <ak@linux.intel.com>,
"Tim Chen" <tim.c.chen@linux.intel.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"Schaufler, Casey" <casey.schaufler@intel.com>
Subject: RE: [PATCH v6 1/3] x86/speculation: apply IBPB more strictly to avoid cross-process data leak
Date: Thu, 13 Sep 2018 00:04:49 +0000 [thread overview]
Message-ID: <99FC4B6EFCEFD44486C35F4C281DC6732144BFBC@ORSMSX107.amr.corp.intel.com> (raw)
In-Reply-To: <nycvar.YFH.7.76.1809121105330.15880@cbobk.fhfr.pm>
> -----Original Message-----
> From: Jiri Kosina [mailto:jikos@kernel.org]
>
>
> @@ -325,10 +326,13 @@ static int __ptrace_may_access(struct task_struct
> *task, unsigned int mode)
> mm = task->mm;
> if (mm &&
> ((get_dumpable(mm) != SUID_DUMP_USER) &&
> - !ptrace_has_cap(mm->user_ns, mode)))
> + ((mode & PTRACE_MODE_NOACCESS_CHK) ||
> + !ptrace_has_cap(mm->user_ns, mode))))
> return -EPERM;
>
> - return security_ptrace_access_check(task, mode);
> + if (!(mode & PTRACE_MODE_NOACCESS_CHK))
> + return security_ptrace_access_check(task, mode);
> + return 0;
Because PTRACE_MODE_IBPB includes PTRACE_MODE_NOAUDIT you
shouldn't need this change. Do you have a good way to exercise this code
path? I'm having trouble getting to the check, and have yet to get a case
where PTRACE_MODE_NOACCESS_CHK is set.
> }
>
> bool ptrace_may_access(struct task_struct *task, unsigned int mode)
>
> --
> Jiri Kosina
> SUSE Labs
next prev parent reply other threads:[~2018-09-13 0:05 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-10 9:22 [PATCH v5 0/2] Harden spectrev2 userspace-userspace protection Jiri Kosina
2018-09-10 9:23 ` [PATCH v5 1/2] x86/speculation: apply IBPB more strictly to avoid cross-process data leak Jiri Kosina
2018-09-10 18:26 ` Schaufler, Casey
2018-09-10 19:14 ` Jiri Kosina
2018-09-10 19:26 ` Schaufler, Casey
2018-09-10 19:36 ` Jiri Kosina
2018-09-10 20:27 ` Schaufler, Casey
2018-09-10 20:42 ` Jiri Kosina
2018-09-10 21:29 ` Schaufler, Casey
2018-09-10 21:36 ` Jiri Kosina
2018-09-11 21:15 ` Thomas Gleixner
2018-09-11 22:25 ` Schaufler, Casey
2018-09-12 12:01 ` Thomas Gleixner
2018-10-21 19:38 ` Pavel Machek
2018-10-21 23:32 ` Jiri Kosina
2018-09-10 9:24 ` [PATCH v5 2/2] x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation Jiri Kosina
2018-09-10 10:04 ` Thomas Gleixner
2018-09-10 11:01 ` Jiri Kosina
2018-09-10 11:46 ` Jiri Kosina
2018-09-11 17:32 ` Tim Chen
2018-09-11 21:16 ` Thomas Gleixner
2018-09-11 21:46 ` Thomas Gleixner
2018-09-12 17:16 ` Tom Lendacky
2018-09-12 21:26 ` Tim Chen
2018-09-12 21:45 ` Jiri Kosina
2018-09-12 22:56 ` Tim Chen
2018-09-13 14:53 ` Tom Lendacky
2018-09-12 9:05 ` [PATCH v6 0/3] Harden spectrev2 userspace-userspace protection Jiri Kosina
2018-09-12 9:06 ` [PATCH v6 1/3] x86/speculation: apply IBPB more strictly to avoid cross-process data leak Jiri Kosina
2018-09-13 0:04 ` Schaufler, Casey [this message]
2018-09-14 11:00 ` Jiri Kosina
2018-09-14 11:05 ` Thomas Gleixner
2018-09-12 9:07 ` [PATCH v6 2/3] x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation Jiri Kosina
2018-09-12 19:14 ` Thomas Gleixner
2018-09-12 19:16 ` Jiri Kosina
2018-09-12 9:08 ` [PATCH v6 3/3] x86/speculation: Propagate information about RSB filling mitigation to sysfs Jiri Kosina
2018-09-17 16:09 ` [PATCH v6 0/3] Harden spectrev2 userspace-userspace protection Schaufler, Casey
2018-09-19 15:48 ` Peter Zijlstra
2018-09-22 7:38 ` Jiri Kosina
2018-09-22 9:53 ` Thomas Gleixner
2018-09-22 10:18 ` Peter Zijlstra
2018-09-22 10:20 ` Thomas Gleixner
2018-09-22 13:30 ` Thomas Gleixner
2018-09-22 14:31 ` Peter Zijlstra
2018-09-24 8:43 ` Jiri Kosina
2018-09-24 12:38 ` Thomas Gleixner
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