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From: Jann Horn <jannh@google.com>
To: rick.p.edgecombe@intel.com
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Kees Cook <keescook@chromium.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	"David S. Miller" <davem@davemloft.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"the arch/x86 maintainers" <x86@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	jeyu@kernel.org, linux-arm-kernel@lists.infradead.org,
	kernel list <linux-kernel@vger.kernel.org>,
	linux-mips@linux-mips.org,
	linux-s390 <linux-s390@vger.kernel.org>,
	sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-arch <linux-arch@vger.kernel.org>,
	kristen@linux.intel.com, Dave Hansen <dave.hansen@intel.com>,
	Arjan van de Ven <arjan@linux.intel.com>,
	deneen.t.dock@intel.com
Subject: Re: [PATCH v2 1/7] modules: Create rlimit for module space
Date: Fri, 12 Oct 2018 20:23:15 +0200	[thread overview]
Message-ID: <CAG48ez0pPX7XNqSj4dVG1s+PaDBCh4ar5xw1WcY1sLBPV_QAzA@mail.gmail.com> (raw)
In-Reply-To: <CAG48ez2fWg64nGxDXUQS3695KpVNrakAbarXJnYPd6xv5wOD+A@mail.gmail.com>

On Fri, Oct 12, 2018 at 2:35 AM Jann Horn <jannh@google.com> wrote:
> On Fri, Oct 12, 2018 at 1:40 AM Rick Edgecombe
> <rick.p.edgecombe@intel.com> wrote:
> > This introduces a new rlimit, RLIMIT_MODSPACE, which limits the amount of
> > module space a user can use. The intention is to be able to limit module space
> > allocations that may come from un-privlidged users inserting e/BPF filters.
>
> Note that in some configurations (iirc e.g. the default Ubuntu
> config), normal users can use the subuid mechanism (the /etc/subuid
> config file and the /usr/bin/newuidmap setuid helper) to gain access
> to 65536 UIDs, which means that in such a configuration,
> RLIMIT_MODSPACE*65537 is the actual limit for one user. (Same thing
> applies to RLIMIT_MEMLOCK.)

Actually, I may have misremembered, perhaps it's not installed by
default - I just checked in a Ubuntu VM, and the newuidmap helper from
the uidmap package wasn't installed.

  parent reply	other threads:[~2018-10-13  1:57 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-11 23:31 [PATCH v2 0/7] Rlimit for module space Rick Edgecombe
2018-10-11 23:31 ` [PATCH v2 1/7] modules: Create rlimit " Rick Edgecombe
2018-10-12  0:35   ` Jann Horn
2018-10-12 17:04     ` Edgecombe, Rick P
2018-10-12 17:22       ` Jann Horn
2018-10-13  0:04         ` Edgecombe, Rick P
2018-10-13  0:09           ` Jann Horn
2018-10-23 11:32       ` Michal Hocko
2018-10-12 18:23     ` Jann Horn [this message]
2018-10-11 23:31 ` [PATCH v2 2/7] x86/modules: Add rlimit checking for x86 modules Rick Edgecombe
2018-10-11 23:31 ` [PATCH v2 3/7] arm/modules: Add rlimit checking for arm modules Rick Edgecombe
2018-10-11 23:31 ` [PATCH v2 4/7] arm64/modules: Add rlimit checking for arm64 modules Rick Edgecombe
2018-10-11 23:47   ` Dave Hansen
2018-10-12 14:32     ` Jessica Yu
2018-10-12 22:01       ` Edgecombe, Rick P
2018-10-12 22:54         ` Edgecombe, Rick P
2018-10-11 23:31 ` [PATCH v2 5/7] mips/modules: Add rlimit checking for mips modules Rick Edgecombe
2018-10-11 23:31 ` [PATCH v2 6/7] sparc/modules: Add rlimit for sparc modules Rick Edgecombe
2018-10-11 23:31 ` [PATCH v2 7/7] s390/modules: Add rlimit checking for s390 modules Rick Edgecombe

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