Jiri Kosina cacd9385b7 x86/speculation: Apply IBPB more strictly to avoid cross-process data leak ... commit dbfe2953f6 upstream Currently, IBPB is only issued in cases when switching into a non-dumpable process, the rationale being to protect such 'important and security sensitive' processess (such as GPG) from data leaking into a different userspace process via spectre v2. This is however completely insufficient to provide proper userspace-to-userpace spectrev2 protection, as any process can poison branch buffers before being scheduled out, and the newly scheduled process immediately becomes spectrev2 victim. In order to minimize the performance impact (for usecases that do require spectrev2 protection), issue the barrier only in cases when switching between processess where the victim can't be ptraced by the potential attacker (as in such cases, the attacker doesn't have to bother with branch buffers at all). [ tglx: Split up PTRACE_MODE_NOACCESS_CHK into PTRACE_MODE_SCHED and PTRACE_MODE_IBPB to be able to do ptrace() context tracking reasonably fine-grained ] Fixes: 18bf3c3ea8 ("x86/speculation: Use Indirect Branch Prediction Barrier in context switch") Originally-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "WoodhouseDavid" <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: "SchauflerCasey" <casey.schaufler@intel.com> Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1809251437340.15880@cbobk.fhfr.pm Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2018-12-05 19:32:00 +01:00
..
acpi
asm-generic	vmlinux.lds.h: Fix linker warnings about orphan .LPBX sections	2018-10-12 08:55:29 +11:00
clocksource
crypto	crypto: speck - remove Speck	2018-11-13 11:08:46 -08:00
drm	drm: Get ref on CRTC commit object when waiting for flip_done	2018-10-18 14:23:13 -04:00
dt-bindings	ARM: SoC: late updates	2018-08-25 14:12:36 -07:00
keys
kvm
linux	x86/speculation: Apply IBPB more strictly to avoid cross-process data leak	2018-12-05 19:32:00 +01:00
math-emu
media	media: cec: fix the Signal Free Time calculation	2018-11-13 11:08:53 -08:00
memory
misc
net	tcp: do not release socket ownership in tcp_close()	2018-12-01 09:37:28 +01:00
pcmcia	pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function	2018-08-18 12:30:42 -07:00
ras
rdma	IB/rxe: Revise the ib_wr_opcode enum	2018-11-13 11:08:43 -08:00
scsi
soc	soc: fsl: qbman: add APIs to retrieve the probing status	2018-09-27 15:43:35 -05:00
sound	ASoC: Fixes for v4.19	2018-09-17 18:59:21 +02:00
target
trace	RxRPC fixes	2018-10-10 22:27:38 -07:00
uapi	Revert "netfilter: nft_numgen: add map lookups for numgen random operations"	2018-11-27 16:13:02 +01:00
video	fbdev changes for v4.19:	2018-08-23 15:44:58 -07:00
xen	CONFIG_XEN_PV breaks xen_create_contiguous_region on ARM	2018-11-21 09:19:28 +01:00