Initialize the request queue lock earlier such that the following
race can no longer occur:
blk_init_queue_node blkcg_print_blkgs
blk_alloc_queue_node (1)
q->queue_lock = &q->__queue_lock (2)
blkcg_init_queue(q) (3)
spin_lock_irq(blkg->q->queue_lock) (4)
q->queue_lock = lock (5)
spin_unlock_irq(blkg->q->queue_lock) (6)
(1) allocate an uninitialized queue;
(2) initialize queue_lock to its default internal lock;
(3) initialize blkcg part of request queue, which will create blkg and
then insert it to blkg_list;
(4) traverse blkg_list and find the created blkg, and then take its
queue lock, here it is the default *internal lock*;
(5) *race window*, now queue_lock is overridden with *driver specified
lock*;
(6) now unlock *driver specified lock*, not the locked *internal lock*,
unlock balance breaks.
The changes in this patch are as follows:
- Move the .queue_lock initialization from blk_init_queue_node() into
blk_alloc_queue_node().
- For all all block drivers that initialize .queue_lock explicitly,
change the blk_alloc_queue() call in the driver into a
blk_alloc_queue_node() call and remove the explicit .queue_lock
initialization. Additionally, initialize the spin lock that will
be used as queue lock earlier if necessary.
Reported-by: Joseph Qi <joseph.qi(a)linux.alibaba.com>
Signed-off-by: Bart Van Assche <bart.vanassche(a)wdc.com>
Cc: Christoph Hellwig <hch(a)lst.de>
Cc: Joseph Qi <joseph.qi(a)linux.alibaba.com>
Cc: Philipp Reisner <philipp.reisner(a)linbit.com>
Cc: Ulf Hansson <ulf.hansson(a)linaro.org>
Cc: Kees Cook <keescook(a)chromium.org>
Cc: <stable(a)vger.kernel.org>
---
block/blk-core.c | 24 ++++++++++++++++--------
drivers/block/drbd/drbd_main.c | 3 +--
drivers/block/umem.c | 7 +++----
drivers/mmc/core/queue.c | 3 +--
4 files changed, 21 insertions(+), 16 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 860a039fd1a8..c2c81c5b7420 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -946,6 +946,20 @@ static void blk_rq_timed_out_timer(struct timer_list *t)
kblockd_schedule_work(&q->timeout_work);
}
+/**
+ * blk_alloc_queue_node - allocate a request queue
+ * @gfp_mask: memory allocation flags
+ * @node_id: NUMA node to allocate memory from
+ * @lock: Pointer to a spinlock that will be used to e.g. serialize calls to
+ * the legacy .request_fn(). Only set this pointer for queues that use
+ * legacy mode and not for queues that use blk-mq.
+ *
+ * Note: pass the queue lock as the third argument to this function instead of
+ * setting the queue lock pointer explicitly to avoid triggering a crash in
+ * the blkcg throttling code. That code namely makes sysfs attributes visible
+ * in user space before this function returns and the show methods of these
+ * sysfs attributes use the queue lock.
+ */
struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id,
spinlock_t *lock)
{
@@ -998,11 +1012,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id,
mutex_init(&q->sysfs_lock);
spin_lock_init(&q->__queue_lock);
- /*
- * By default initialize queue_lock to internal lock and driver can
- * override it later if need be.
- */
- q->queue_lock = &q->__queue_lock;
+ q->queue_lock = lock ? : &q->__queue_lock;
/*
* A queue starts its life with bypass turned on to avoid
@@ -1089,13 +1099,11 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
{
struct request_queue *q;
- q = blk_alloc_queue_node(GFP_KERNEL, node_id, NULL);
+ q = blk_alloc_queue_node(GFP_KERNEL, node_id, lock);
if (!q)
return NULL;
q->request_fn = rfn;
- if (lock)
- q->queue_lock = lock;
if (blk_init_allocated_queue(q) < 0) {
blk_cleanup_queue(q);
return NULL;
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 4b4697a1f963..058247bc2f30 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2822,7 +2822,7 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
drbd_init_set_defaults(device);
- q = blk_alloc_queue(GFP_KERNEL);
+ q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE, &resource->req_lock);
if (!q)
goto out_no_q;
device->rq_queue = q;
@@ -2854,7 +2854,6 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
/* Setting the max_hw_sectors to an odd value of 8kibyte here
This triggers a max_bio_size message upon first attach or connect */
blk_queue_max_hw_sectors(q, DRBD_MAX_BIO_SIZE_SAFE >> 8);
- q->queue_lock = &resource->req_lock;
device->md_io.page = alloc_page(GFP_KERNEL);
if (!device->md_io.page)
diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 8077123678ad..5c7fb8cc4149 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -888,13 +888,14 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
card->Active = -1; /* no page is active */
card->bio = NULL;
card->biotail = &card->bio;
+ spin_lock_init(&card->lock);
- card->queue = blk_alloc_queue(GFP_KERNEL);
+ card->queue = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE,
+ &card->lock);
if (!card->queue)
goto failed_alloc;
blk_queue_make_request(card->queue, mm_make_request);
- card->queue->queue_lock = &card->lock;
card->queue->queuedata = card;
tasklet_init(&card->tasklet, process_page, (unsigned long)card);
@@ -968,8 +969,6 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
dev_printk(KERN_INFO, &card->dev->dev,
"Window size %d bytes, IRQ %d\n", data, dev->irq);
- spin_lock_init(&card->lock);
-
pci_set_drvdata(dev, card);
if (pci_write_cmd != 0x0F) /* If not Memory Write & Invalidate */
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 5ecd54088988..bcf6ae03fa97 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -216,10 +216,9 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
int ret = -ENOMEM;
mq->card = card;
- mq->queue = blk_alloc_queue(GFP_KERNEL);
+ mq->queue = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE, lock);
if (!mq->queue)
return -ENOMEM;
- mq->queue->queue_lock = lock;
mq->queue->request_fn = mmc_request_fn;
mq->queue->init_rq_fn = mmc_init_request;
mq->queue->exit_rq_fn = mmc_exit_request;
--
2.16.0
Moving the qrwlock struct definition into a header file introduced
a subtle bug on all little-endian machines, where some files in some
configurations would see the fields in an incorrect order. This was
found by building with an LTO enabled compiler that warns every time we
try to link together files with incompatible data structures.
A second patch changes linux/kconfig.h to always define the symbols,
but this seems to be the root cause of most of the issues, so I'd suggest
we do both.
On a current linux-next kernel, I verified that this header is
responsible for all type mismatches as a result from the endianess
confusion.
Cc: stable(a)vger.kernel.org
Cc: Will Deacon <will.deacon(a)arm.com>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Fixes: e0d02285f16e ("locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock'")
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
---
include/asm-generic/qrwlock_types.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/asm-generic/qrwlock_types.h b/include/asm-generic/qrwlock_types.h
index 137ecdd16daa..c36f1d5a2572 100644
--- a/include/asm-generic/qrwlock_types.h
+++ b/include/asm-generic/qrwlock_types.h
@@ -3,6 +3,7 @@
#define __ASM_GENERIC_QRWLOCK_TYPES_H
#include <linux/types.h>
+#include <asm/byteorder.h>
#include <asm/spinlock_types.h>
/*
--
2.9.0
The patch titled
Subject: Kbuild: always define endianess in kconfig.h
has been added to the -mm tree. Its filename is
kbuild-always-define-endianess-in-kconfigh.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/kbuild-always-define-endianess-in-…
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/kbuild-always-define-endianess-in-…
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Arnd Bergmann <arnd(a)arndb.de>
Subject: Kbuild: always define endianess in kconfig.h
Build testing with LTO found a couple of files that get compiled
differently depending on whether asm/byteorder.h gets included early
enough or not. In particular, include/asm-generic/qrwlock_types.h is
affected by this, but there are probably others as well.
The symptom is a series of LTO link time warnings, including these:
net/netlabel/netlabel_unlabeled.h:223: error: type of 'netlbl_unlhsh_add' does not match original declaration [-Werror=lto-type-mismatch]
int netlbl_unlhsh_add(struct net *net,
net/netlabel/netlabel_unlabeled.c:377: note: 'netlbl_unlhsh_add' was previously declared here
include/net/ipv6.h:360: error: type of 'ipv6_renew_options_kern' does not match original declaration [-Werror=lto-type-mismatch]
ipv6_renew_options_kern(struct sock *sk,
net/ipv6/exthdrs.c:1162: note: 'ipv6_renew_options_kern' was previously declared here
net/core/dev.c:761: note: 'dev_get_by_name_rcu' was previously declared here
struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
net/core/dev.c:761: note: code may be misoptimized unless -fno-strict-aliasing is used
drivers/gpu/drm/i915/i915_drv.h:3377: error: type of 'i915_gem_object_set_to_wc_domain' does not match original declaration [-Werror=lto-type-mismatch]
i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write);
drivers/gpu/drm/i915/i915_gem.c:3639: note: 'i915_gem_object_set_to_wc_domain' was previously declared here
include/linux/debugfs.h:92:9: error: type of 'debugfs_attr_read' does not match original declaration [-Werror=lto-type-mismatch]
ssize_t debugfs_attr_read(struct file *file, char __user *buf,
fs/debugfs/file.c:318: note: 'debugfs_attr_read' was previously declared here
include/linux/rwlock_api_smp.h:30: error: type of '_raw_read_unlock' does not match original declaration [-Werror=lto-type-mismatch]
void __lockfunc _raw_read_unlock(rwlock_t *lock) __releases(lock);
kernel/locking/spinlock.c:246:26: note: '_raw_read_unlock' was previously declared here
include/linux/fs.h:3308:5: error: type of 'simple_attr_open' does not match original declaration [-Werror=lto-type-mismatch]
int simple_attr_open(struct inode *inode, struct file *file,
fs/libfs.c:795: note: 'simple_attr_open' was previously declared here
All of the above are caused by include/asm-generic/qrwlock_types.h failing
to include asm/byteorder.h after commit e0d02285f16e ("locking/qrwlock:
Use 'struct qrwlock' instead of 'struct __qrwlock'") in linux-4.15.
Similar bugs may or may not exist in older kernels as well, but there is
no easy way to test those with link-time optimizations, and kernels before
4.14 are harder to fix because they don't have Babu's patch series
We had similar issues with CONFIG_ symbols in the past and ended up always
including the configuration headers though linux/kconfig.h. This works
around the issue through that same file, defining either __BIG_ENDIAN or
__LITTLE_ENDIAN depending on CONFIG_CPU_BIG_ENDIAN, which is now always
set on all architectures since commit 4c97a0c8fee3 ("arch: define
CPU_BIG_ENDIAN for all fixed big endian archs").
Link: http://lkml.kernel.org/r/20180202154104.1522809-2-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Cc: Babu Moger <babu.moger(a)oracle.com>
Cc: Andi Kleen <ak(a)linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: Nicolas Pitre <nico(a)linaro.org>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Will Deacon <will.deacon(a)arm.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
include/linux/kconfig.h | 6 ++++++
1 file changed, 6 insertions(+)
diff -puN include/linux/kconfig.h~kbuild-always-define-endianess-in-kconfigh include/linux/kconfig.h
--- a/include/linux/kconfig.h~kbuild-always-define-endianess-in-kconfigh
+++ a/include/linux/kconfig.h
@@ -4,6 +4,12 @@
#include <generated/autoconf.h>
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define __BIG_ENDIAN 4321
+#else
+#define __LITTLE_ENDIAN 1234
+#endif
+
#define __ARG_PLACEHOLDER_1 0,
#define __take_second_arg(__ignored, val, ...) val
_
Patches currently in -mm which might be from arnd(a)arndb.de are
locking-qrwlock-include-asm-byteorderh-as-needed.patch
kbuild-always-define-endianess-in-kconfigh.patch
kasan-added-functions-for-unpoisoning-stack-variables-fix-fix.patch
bugh-work-around-gcc-pr82365-in-bug.patch
bitmap-replace-bitmap_fromto_u32array-fix.patch
nilfs2-use-time64_t-internally.patch
pps-parport-use-timespec64-instead-of-timespec.patch
kasan-rework-kconfig-settings.patch
The patch titled
Subject: locking/qrwlock: include asm/byteorder.h as needed
has been added to the -mm tree. Its filename is
locking-qrwlock-include-asm-byteorderh-as-needed.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/locking-qrwlock-include-asm-byteor…
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/locking-qrwlock-include-asm-byteor…
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Arnd Bergmann <arnd(a)arndb.de>
Subject: locking/qrwlock: include asm/byteorder.h as needed
Moving the qrwlock struct definition into a header file introduced a
subtle bug on all little-endian machines, where some files in some
configurations would see the fields in an incorrect order. This was found
by building with an LTO enabled compiler that warns every time we try to
link together files with incompatible data structures.
A second patch changes linux/kconfig.h to always define the symbols, but
this seems to be the root cause of most of the issues, so I'd suggest we
do both.
On a current linux-next kernel, I verified that this header is responsible
for all type mismatches as a result from the endianess confusion.
Link: http://lkml.kernel.org/r/20180202154104.1522809-1-arnd@arndb.de
Fixes: e0d02285f16e ("locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock'")
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Cc: Will Deacon <will.deacon(a)arm.com>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Nicolas Pitre <nico(a)linaro.org>
Cc: Andi Kleen <ak(a)linux.intel.com>
Cc: Babu Moger <babu.moger(a)oracle.com>
Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
include/asm-generic/qrwlock_types.h | 1 +
1 file changed, 1 insertion(+)
diff -puN include/asm-generic/qrwlock_types.h~locking-qrwlock-include-asm-byteorderh-as-needed include/asm-generic/qrwlock_types.h
--- a/include/asm-generic/qrwlock_types.h~locking-qrwlock-include-asm-byteorderh-as-needed
+++ a/include/asm-generic/qrwlock_types.h
@@ -3,6 +3,7 @@
#define __ASM_GENERIC_QRWLOCK_TYPES_H
#include <linux/types.h>
+#include <asm/byteorder.h>
#include <asm/spinlock_types.h>
/*
_
Patches currently in -mm which might be from arnd(a)arndb.de are
locking-qrwlock-include-asm-byteorderh-as-needed.patch
kbuild-always-define-endianess-in-kconfigh.patch
kasan-added-functions-for-unpoisoning-stack-variables-fix-fix.patch
bugh-work-around-gcc-pr82365-in-bug.patch
bitmap-replace-bitmap_fromto_u32array-fix.patch
nilfs2-use-time64_t-internally.patch
pps-parport-use-timespec64-instead-of-timespec.patch
kasan-rework-kconfig-settings.patch
When running as Xen pv guest %gs is initialized some time after
C code is started. Depending on stack protector usage this might be
too late, resulting in page faults.
So setup %gs and MSR_GS_BASE in assembly code already.
Cc: stable(a)vger.kernel.org
Signed-off-by: Juergen Gross <jgross(a)suse.com>
---
arch/x86/xen/xen-head.S | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 497cc55a0c16..96f26e026783 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -9,7 +9,9 @@
#include <asm/boot.h>
#include <asm/asm.h>
+#include <asm/msr.h>
#include <asm/page_types.h>
+#include <asm/percpu.h>
#include <asm/unwind_hints.h>
#include <xen/interface/elfnote.h>
@@ -35,6 +37,20 @@ ENTRY(startup_xen)
mov %_ASM_SI, xen_start_info
mov $init_thread_union+THREAD_SIZE, %_ASM_SP
+#ifdef CONFIG_X86_64
+ /* Set up %gs.
+ *
+ * The base of %gs always points to the bottom of the irqstack
+ * union. If the stack protector canary is enabled, it is
+ * located at %gs:40. Note that, on SMP, the boot cpu uses
+ * init data section till per cpu areas are set up.
+ */
+ movl $MSR_GS_BASE,%ecx
+ movq $INIT_PER_CPU_VAR(irq_stack_union),%rax
+ cdq
+ wrmsr
+#endif
+
jmp xen_start_kernel
END(startup_xen)
__FINIT
--
2.13.6
[ Upstream commit 0f5eb1545907edeea7672a9c1652c4231150ff22 ]
Both fpga_region_get_manager() and fpga_region_get_bridges() call
of_parse_phandle(), but nothing calls of_node_put() on the returned
struct device_node pointers. Make sure to do that to stop their
reference counters getting out of whack.
Fixes: 0fa20cdfcc1f ("fpga: fpga-region: device tree control for FPGA")
Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk>
Signed-off-by: Alan Tull <atull(a)kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/fpga/fpga-region.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index d9ab7c75b14f..e0c73ceba2ed 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -147,6 +147,7 @@ static struct fpga_manager *fpga_region_get_manager(struct fpga_region *region)
mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
if (mgr_node) {
mgr = of_fpga_mgr_get(mgr_node);
+ of_node_put(mgr_node);
of_node_put(np);
return mgr;
}
@@ -192,10 +193,13 @@ static int fpga_region_get_bridges(struct fpga_region *region,
parent_br = region_np->parent;
/* If overlay has a list of bridges, use it. */
- if (of_parse_phandle(overlay, "fpga-bridges", 0))
+ br = of_parse_phandle(overlay, "fpga-bridges", 0);
+ if (br) {
+ of_node_put(br);
np = overlay;
- else
+ } else {
np = region_np;
+ }
for (i = 0; ; i++) {
br = of_parse_phandle(np, "fpga-bridges", i);
@@ -203,12 +207,15 @@ static int fpga_region_get_bridges(struct fpga_region *region,
break;
/* If parent bridge is in list, skip it. */
- if (br == parent_br)
+ if (br == parent_br) {
+ of_node_put(br);
continue;
+ }
/* If node is a bridge, get it and add to list */
ret = fpga_bridge_get_to_list(br, region->info,
®ion->bridge_list);
+ of_node_put(br);
/* If any of the bridges are in use, give up */
if (ret == -EBUSY) {
--
2.15.1
gcc-8 warns about some obviously incorrect code:
net/mac80211/cfg.c: In function 'cfg80211_beacon_dup':
net/mac80211/cfg.c:2896:3: error: 'memcpy' source argument is the same as destination [-Werror=restrict]
>From the context, I conclude that we want to copy from beacon into
new_beacon, as we do in the rest of the function.
Cc: stable(a)vger.kernel.org
Fixes: 73da7d5bab79 ("mac80211: add channel switch command and beacon callbacks")
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
---
net/mac80211/cfg.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 46028e12e216..f4195a0f0279 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2892,7 +2892,7 @@ cfg80211_beacon_dup(struct cfg80211_beacon_data *beacon)
}
if (beacon->probe_resp_len) {
new_beacon->probe_resp_len = beacon->probe_resp_len;
- beacon->probe_resp = pos;
+ new_beacon->probe_resp = pos;
memcpy(pos, beacon->probe_resp, beacon->probe_resp_len);
pos += beacon->probe_resp_len;
}
--
2.9.0
This is a note to let you know that I've just added the patch titled
x86/efi: Clarify that reset attack mitigation needs appropriate userspace
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
x86-efi-clarify-that-reset-attack-mitigation-needs-appropriate-userspace.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From a5c03c31af2291f13689d11760c0b59fb70c9a5a Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg59(a)google.com>
Date: Tue, 16 Jan 2018 09:10:02 +0000
Subject: x86/efi: Clarify that reset attack mitigation needs appropriate userspace
From: Matthew Garrett <mjg59(a)google.com>
commit a5c03c31af2291f13689d11760c0b59fb70c9a5a upstream.
Some distributions have turned on the reset attack mitigation feature,
which is designed to force the platform to clear the contents of RAM if
the machine is shut down uncleanly. However, in order for the platform
to be able to determine whether the shutdown was clean or not, userspace
has to be configured to clear the MemoryOverwriteRequest flag on
shutdown - otherwise the firmware will end up clearing RAM on every
reboot, which is unnecessarily time consuming. Add some additional
clarity to the kconfig text to reduce the risk of systems being
configured this way.
Signed-off-by: Matthew Garrett <mjg59(a)google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel(a)linaro.org>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: linux-efi(a)vger.kernel.org
Cc: linux-kernel(a)vger.kernel.org
Signed-off-by: Ingo Molnar <mingo(a)kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/firmware/efi/Kconfig | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -159,7 +159,10 @@ config RESET_ATTACK_MITIGATION
using the TCG Platform Reset Attack Mitigation specification. This
protects against an attacker forcibly rebooting the system while it
still contains secrets in RAM, booting another OS and extracting the
- secrets.
+ secrets. This should only be enabled when userland is configured to
+ clear the MemoryOverwriteRequest flag on clean shutdown after secrets
+ have been evicted, since otherwise it will trigger even on clean
+ reboots.
endmenu
Patches currently in stable-queue which might be from mjg59(a)google.com are
queue-4.15/x86-efi-clarify-that-reset-attack-mitigation-needs-appropriate-userspace.patch
This is a note to let you know that I've just added the patch titled
usbip: prevent bind loops on devices attached to vhci_hcd
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
usbip-prevent-bind-loops-on-devices-attached-to-vhci_hcd.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From ef54cf0c600fb8f5737fb001a9e357edda1a1de8 Mon Sep 17 00:00:00 2001
From: Shuah Khan <shuahkh(a)osg.samsung.com>
Date: Wed, 17 Jan 2018 12:07:30 -0700
Subject: usbip: prevent bind loops on devices attached to vhci_hcd
From: Shuah Khan <shuahkh(a)osg.samsung.com>
commit ef54cf0c600fb8f5737fb001a9e357edda1a1de8 upstream.
usbip host binds to devices attached to vhci_hcd on the same server
when user does attach over localhost or specifies the server as the
remote.
usbip attach -r localhost -b busid
or
usbip attach -r servername (or server IP)
Unbind followed by bind works, however device is left in a bad state with
accesses via the attached busid result in errors and system hangs during
shutdown.
Fix it to check and bail out if the device is already attached to vhci_hcd.
Signed-off-by: Shuah Khan <shuahkh(a)osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
tools/usb/usbip/src/usbip_bind.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/tools/usb/usbip/src/usbip_bind.c
+++ b/tools/usb/usbip/src/usbip_bind.c
@@ -144,6 +144,7 @@ static int bind_device(char *busid)
int rc;
struct udev *udev;
struct udev_device *dev;
+ const char *devpath;
/* Check whether the device with this bus ID exists. */
udev = udev_new();
@@ -152,8 +153,16 @@ static int bind_device(char *busid)
err("device with the specified bus ID does not exist");
return -1;
}
+ devpath = udev_device_get_devpath(dev);
udev_unref(udev);
+ /* If the device is already attached to vhci_hcd - bail out */
+ if (strstr(devpath, USBIP_VHCI_DRV_NAME)) {
+ err("bind loop detected: device: %s is attached to %s\n",
+ devpath, USBIP_VHCI_DRV_NAME);
+ return -1;
+ }
+
rc = unbind_other(busid);
if (rc == UNBIND_ST_FAILED) {
err("could not unbind driver from device on busid %s", busid);
Patches currently in stable-queue which might be from shuahkh(a)osg.samsung.com are
queue-4.15/usbip-list-don-t-list-devices-attached-to-vhci_hcd.patch
queue-4.15/usbip-prevent-bind-loops-on-devices-attached-to-vhci_hcd.patch