Commit be36f9e7517e ("efi: READ_ONCE rng seed size before munmap")
added a READ_ONCE() and also changed the call to
add_bootloader_randomness() to use the local size variable. Neither
of these changes was actually needed and this was not backported to
the 4.14 stable branch.
Commit 161a438d730d ("efi: random: reduce seed size to 32 bytes")
reverted the addition of READ_ONCE() and added a limit to the value of
size. This depends on the earlier commit, because size can now differ
from seed->size, but it was wrongly backported to the 4.14 stable
branch by itself.
Apply the missing change to the add_bootloader_randomness() parameter
(except that here we are still using add_device_randomness()).
Fixes: 700485f70e50 ("efi: random: reduce seed size to 32 bytes")
Signed-off-by: Ben Hutchings <ben(a)decadent.org.uk>
---
drivers/firmware/efi/efi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index ed981f5e29ae..cc64869d8420 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -541,7 +541,7 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
seed = early_memremap(efi.rng_seed,
sizeof(*seed) + size);
if (seed != NULL) {
- add_device_randomness(seed->bits, seed->size);
+ add_device_randomness(seed->bits, size);
early_memunmap(seed, sizeof(*seed) + size);
pr_notice("seeding entropy pool\n");
} else {
Hello!
Would the stable maintainers please consider backporting the following
series of patches?:
https://lore.kernel.org/lkml/20220801013834.156015-1-andres@anarazel.de/
Branches where this is needed are:
* 5.4
* 5.10
* 5.15
Branch 6.0.y is fine, as this series is present there.
Failure is seen in this form:
-----8<----------8<----------8<-----
util/annotate.c: In function 'symbol__disassemble_bpf':
util/annotate.c:1739:9: error: too few arguments to function
'init_disassemble_info'
1739 | init_disassemble_info(&info, s,
| ^~~~~~~~~~~~~~~~~~~~~
In file included from util/annotate.c:1692:
/usr/include/dis-asm.h:472:13: note: declared here
472 | extern void init_disassemble_info (struct disassemble_info
*dinfo, void *stream,
| ^~~~~~~~~~~~~~~~~~~~~
make[4]: *** [/builds/linux/tools/build/Makefile.build:96:
/home/tuxbuild/.cache/tuxmake/builds/1/build/util/annotate.o] Error 1
----->8---------->8---------->8-----
The 5.15 backport is almost straight-forward, with patches 7 and 8
requiring some small modifications. I could not get the 5.10 backport
to build, and for 5.4 it was even more difficult to adapt.
Thanks and greetings!
Daniel Díaz
daniel.diaz(a)linaro.org
Hello!
The first patch fixes an issue reported by Sami, where linux panic()s
when bringing secondary CPUs online. The problem was the Spectre
workarounds trying to allocate a new slot for mitigating KVM when
those pages are no longer writeable.
While debugging that issue, I spotted the Spectre-BHB KVM mitigation was
over-riding the Spectre-v2 KVM Mitigation. It's supposed to happen the
other way round.
The backports aren't the same as mainline because the spectre mitigation code
was totally rewritten for v5.10, and prior to that the KVM infrastructure
is very different.
Thanks,
James Morse (2):
arm64: Fix panic() when Spectre-v2 causes Spectre-BHB to re-allocate
KVM vectors
arm64: errata: Fix KVM Spectre-v2 mitigation selection for
Cortex-A57/A72
arch/arm64/kernel/cpu_errata.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
--
2.30.2
commit 47b0c2e4c220f2251fd8dcfbb44479819c715e15 upstream.
make_mmu_pages_available() must be called with mmu_lock held for write.
However, if the TDP MMU is used, it will be called with mmu_lock held for
read.
This function does nothing unless shadow pages are used, so there is no
race unless nested TDP is used.
Since nested TDP uses shadow pages, old shadow pages may be zapped by this
function even when the TDP MMU is enabled.
Since shadow pages are never allocated by kvm_tdp_mmu_map(), a race
condition can be avoided by not calling make_mmu_pages_available() if the
TDP MMU is currently in use.
I encountered this when repeatedly starting and stopping nested VM.
It can be artificially caused by allocating a large number of nested TDP
SPTEs.
For example, the following BUG and general protection fault are caused in
the host kernel.
pte_list_remove: 00000000cd54fc10 many->many
------------[ cut here ]------------
kernel BUG at arch/x86/kvm/mmu/mmu.c:963!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:pte_list_remove.cold+0x16/0x48 [kvm]
Call Trace:
<TASK>
drop_spte+0xe0/0x180 [kvm]
mmu_page_zap_pte+0x4f/0x140 [kvm]
__kvm_mmu_prepare_zap_page+0x62/0x3e0 [kvm]
kvm_mmu_zap_oldest_mmu_pages+0x7d/0xf0 [kvm]
direct_page_fault+0x3cb/0x9b0 [kvm]
kvm_tdp_page_fault+0x2c/0xa0 [kvm]
kvm_mmu_page_fault+0x207/0x930 [kvm]
npf_interception+0x47/0xb0 [kvm_amd]
svm_invoke_exit_handler+0x13c/0x1a0 [kvm_amd]
svm_handle_exit+0xfc/0x2c0 [kvm_amd]
kvm_arch_vcpu_ioctl_run+0xa79/0x1780 [kvm]
kvm_vcpu_ioctl+0x29b/0x6f0 [kvm]
__x64_sys_ioctl+0x95/0xd0
do_syscall_64+0x5c/0x90
general protection fault, probably for non-canonical address
0xdead000000000122: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:kvm_mmu_commit_zap_page.part.0+0x4b/0xe0 [kvm]
Call Trace:
<TASK>
kvm_mmu_zap_oldest_mmu_pages+0xae/0xf0 [kvm]
direct_page_fault+0x3cb/0x9b0 [kvm]
kvm_tdp_page_fault+0x2c/0xa0 [kvm]
kvm_mmu_page_fault+0x207/0x930 [kvm]
npf_interception+0x47/0xb0 [kvm_amd]
CVE: CVE-2022-45869
Fixes: a2855afc7ee8 ("KVM: x86/mmu: Allow parallel page faults for the TDP MMU")
Signed-off-by: Kazuki Takiguchi <takiguchi.kazuki171(a)gmail.com>
Cc: stable(a)vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
---
arch/x86/kvm/mmu/mmu.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index ba1749a770eb..4724289c8a7f 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2357,6 +2357,7 @@ static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm,
{
bool list_unstable;
+ lockdep_assert_held_write(&kvm->mmu_lock);
trace_kvm_mmu_prepare_zap_page(sp);
++kvm->stat.mmu_shadow_zapped;
*nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list);
@@ -4007,16 +4008,17 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
if (!is_noslot_pfn(pfn) && mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, hva))
goto out_unlock;
- r = make_mmu_pages_available(vcpu);
- if (r)
- goto out_unlock;
- if (is_tdp_mmu_fault)
+ if (is_tdp_mmu_fault) {
r = kvm_tdp_mmu_map(vcpu, gpa, error_code, map_writable, max_level,
pfn, prefault);
- else
+ } else {
+ r = make_mmu_pages_available(vcpu);
+ if (r)
+ goto out_unlock;
r = __direct_map(vcpu, gpa, error_code, map_writable, max_level, pfn,
prefault, is_tdp);
+ }
out_unlock:
if (is_tdp_mmu_fault)
--
2.34.1
Commit fbd567e56942ecc4da906c4f3f3652c94773af5b upstream.
The member void *data in the structure devfreq can be overwrite
by governor_userspace. For example:
1. The device driver assigned the devfreq governor to simple_ondemand
by the function devfreq_add_device() and init the devfreq member
void *data to a pointer of a static structure devfreq_simple_ondemand_data
by the function devfreq_add_device().
2. The user changed the devfreq governor to userspace by the command
"echo userspace > /sys/class/devfreq/.../governor".
3. The governor userspace alloced a dynamic memory for the struct
userspace_data and assigend the member void *data of devfreq to
this memory by the function userspace_init().
4. The user changed the devfreq governor back to simple_ondemand
by the command "echo simple_ondemand > /sys/class/devfreq/.../governor".
5. The governor userspace exited and assigned the member void *data
in the structure devfreq to NULL by the function userspace_exit().
6. The governor simple_ondemand fetched the static information of
devfreq_simple_ondemand_data in the function
devfreq_simple_ondemand_func() but the member void *data of devfreq was
assigned to NULL by the function userspace_exit().
7. The information of upthreshold and downdifferential is lost
and the governor simple_ondemand can't work correctly.
The member void *data in the structure devfreq is designed for
a static pointer used in a governor and inited by the function
devfreq_add_device(). This patch add an element named governor_data
in the devfreq structure which can be used by a governor(E.g userspace)
who want to assign a private data to do some private things.
Fixes: ce26c5bb9569 ("PM / devfreq: Add basic governors")
Cc: stable(a)vger.kernel.org # 5.4-
Signed-off-by: Kant Fan <kant(a)allwinnertech.com>
---
drivers/devfreq/devfreq.c | 6 ++----
drivers/devfreq/governor_userspace.c | 12 ++++++------
include/linux/devfreq.h | 7 ++++---
3 files changed, 12 insertions(+), 13 deletions(-)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index c79652ee94be..93efaf69d08e 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -603,8 +603,7 @@ static void devfreq_dev_release(struct device *dev)
* @dev: the device to add devfreq feature.
* @profile: device-specific profile to run devfreq.
* @governor_name: name of the policy to choose frequency.
- * @data: private data for the governor. The devfreq framework does not
- * touch this value.
+ * @data: devfreq driver pass to governors, governor should not change it.
*/
struct devfreq *devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
@@ -788,8 +787,7 @@ static void devm_devfreq_dev_release(struct device *dev, void *res)
* @dev: the device to add devfreq feature.
* @profile: device-specific profile to run devfreq.
* @governor_name: name of the policy to choose frequency.
- * @data: private data for the governor. The devfreq framework does not
- * touch this value.
+ * @data: devfreq driver pass to governors, governor should not change it.
*
* This function manages automatically the memory of devfreq device using device
* resource management and simplify the free operation for memory of devfreq
diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c
index af94942fcf95..a3ae4dc4668b 100644
--- a/drivers/devfreq/governor_userspace.c
+++ b/drivers/devfreq/governor_userspace.c
@@ -21,7 +21,7 @@ struct userspace_data {
static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq)
{
- struct userspace_data *data = df->data;
+ struct userspace_data *data = df->governor_data;
if (data->valid)
*freq = data->user_frequency;
@@ -40,7 +40,7 @@ static ssize_t store_freq(struct device *dev, struct device_attribute *attr,
int err = 0;
mutex_lock(&devfreq->lock);
- data = devfreq->data;
+ data = devfreq->governor_data;
sscanf(buf, "%lu", &wanted);
data->user_frequency = wanted;
@@ -60,7 +60,7 @@ static ssize_t show_freq(struct device *dev, struct device_attribute *attr,
int err = 0;
mutex_lock(&devfreq->lock);
- data = devfreq->data;
+ data = devfreq->governor_data;
if (data->valid)
err = sprintf(buf, "%lu\n", data->user_frequency);
@@ -91,7 +91,7 @@ static int userspace_init(struct devfreq *devfreq)
goto out;
}
data->valid = false;
- devfreq->data = data;
+ devfreq->governor_data = data;
err = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group);
out:
@@ -107,8 +107,8 @@ static void userspace_exit(struct devfreq *devfreq)
if (devfreq->dev.kobj.sd)
sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group);
- kfree(devfreq->data);
- devfreq->data = NULL;
+ kfree(devfreq->governor_data);
+ devfreq->governor_data = NULL;
}
static int devfreq_userspace_handler(struct devfreq *devfreq,
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 2bae9ed3c783..6cbc6d1ae32f 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -121,8 +121,8 @@ struct devfreq_dev_profile {
* devfreq.nb to the corresponding register notifier call chain.
* @work: delayed work for load monitoring.
* @previous_freq: previously configured frequency value.
- * @data: Private data of the governor. The devfreq framework does not
- * touch this.
+ * @data: devfreq driver pass to governors, governor should not change it.
+ * @governor_data: private data for governors, devfreq core doesn't touch it.
* @min_freq: Limit minimum frequency requested by user (0: none)
* @max_freq: Limit maximum frequency requested by user (0: none)
* @scaling_min_freq: Limit minimum frequency requested by OPP interface
@@ -159,7 +159,8 @@ struct devfreq {
unsigned long previous_freq;
struct devfreq_dev_status last_status;
- void *data; /* private data for governors */
+ void *data;
+ void *governor_data;
unsigned long min_freq;
unsigned long max_freq;
--
2.29.0
Recent patches for io_uring polling.
Lin Ma (1):
io_uring/poll: fix poll_refs race with cancelation
Pavel Begunkov (4):
io_uring: update res mask in io_poll_check_events
io_uring: fix tw losing poll events
io_uring: cmpxchg for poll arm refs release
io_uring: make poll refs more robust
fs/io_uring.c | 57 ++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 50 insertions(+), 7 deletions(-)
--
2.38.1
The patch below does not apply to the 6.0-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
Possible dependencies:
3c1ea6a5f4f5 ("drm/i915: Remove non-existent pipes from bigjoiner pipe mask")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3c1ea6a5f4f55d4e376675dda16945eb5d9bb4de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala(a)linux.intel.com>
Date: Fri, 18 Nov 2022 20:52:01 +0200
Subject: [PATCH] drm/i915: Remove non-existent pipes from bigjoiner pipe mask
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
bigjoiner_pipes() doesn't consider that:
- RKL only has three pipes
- some pipes may be fused off
This means that intel_atomic_check_bigjoiner() won't reject
all configurations that would need a non-existent pipe.
Instead we just keep on rolling witout actually having
reserved the slave pipe we need.
It's possible that we don't outright explode anywhere due to
this since eg. for_each_intel_crtc_in_pipe_mask() will only
walk the crtcs we've registered even though the passed in
pipe_mask asks for more of them. But clearly the thing won't
do what is expected of it when the required pipes are not
present.
Fix the problem by consulting the device info pipe_mask already
in bigjoiner_pipes().
Cc: stable(a)vger.kernel.org
Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221118185201.10469-1-ville.…
Reviewed-by: Arun R Murthy <arun.r.murthy(a)intel.com>
(cherry picked from commit f1c87a94a1087a26f41007ee83264033007421b5)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)intel.com>
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 461c62c88413..de77054195c6 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -3723,12 +3723,16 @@ static bool ilk_get_pipe_config(struct intel_crtc *crtc,
static u8 bigjoiner_pipes(struct drm_i915_private *i915)
{
+ u8 pipes;
+
if (DISPLAY_VER(i915) >= 12)
- return BIT(PIPE_A) | BIT(PIPE_B) | BIT(PIPE_C) | BIT(PIPE_D);
+ pipes = BIT(PIPE_A) | BIT(PIPE_B) | BIT(PIPE_C) | BIT(PIPE_D);
else if (DISPLAY_VER(i915) >= 11)
- return BIT(PIPE_B) | BIT(PIPE_C);
+ pipes = BIT(PIPE_B) | BIT(PIPE_C);
else
- return 0;
+ pipes = 0;
+
+ return pipes & RUNTIME_INFO(i915)->pipe_mask;
}
static bool transcoder_ddi_func_is_enabled(struct drm_i915_private *dev_priv,
The patch below does not apply to the 6.0-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
Possible dependencies:
95bc35f9bee5 ("mm/damon/sysfs: fix wrong empty schemes assumption under online tuning in damon_sysfs_set_schemes()")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 95bc35f9bee5220dad4e8567654ab3288a181639 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj(a)kernel.org>
Date: Tue, 22 Nov 2022 19:48:31 +0000
Subject: [PATCH] mm/damon/sysfs: fix wrong empty schemes assumption under
online tuning in damon_sysfs_set_schemes()
Commit da87878010e5 ("mm/damon/sysfs: support online inputs update") made
'damon_sysfs_set_schemes()' to be called for running DAMON context, which
could have schemes. In the case, DAMON sysfs interface is supposed to
update, remove, or add schemes to reflect the sysfs files. However, the
code is assuming the DAMON context wouldn't have schemes at all, and
therefore creates and adds new schemes. As a result, the code doesn't
work as intended for online schemes tuning and could have more than
expected memory footprint. The schemes are all in the DAMON context, so
it doesn't leak the memory, though.
Remove the wrong asssumption (the DAMON context wouldn't have schemes) in
'damon_sysfs_set_schemes()' to fix the bug.
Link: https://lkml.kernel.org/r/20221122194831.3472-1-sj@kernel.org
Fixes: da87878010e5 ("mm/damon/sysfs: support online inputs update")
Signed-off-by: SeongJae Park <sj(a)kernel.org>
Cc: <stable(a)vger.kernel.org> [5.19+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 5ce403378c20..07e5f1bdf025 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -2283,12 +2283,54 @@ static struct damos *damon_sysfs_mk_scheme(
&wmarks);
}
+static void damon_sysfs_update_scheme(struct damos *scheme,
+ struct damon_sysfs_scheme *sysfs_scheme)
+{
+ struct damon_sysfs_access_pattern *access_pattern =
+ sysfs_scheme->access_pattern;
+ struct damon_sysfs_quotas *sysfs_quotas = sysfs_scheme->quotas;
+ struct damon_sysfs_weights *sysfs_weights = sysfs_quotas->weights;
+ struct damon_sysfs_watermarks *sysfs_wmarks = sysfs_scheme->watermarks;
+
+ scheme->pattern.min_sz_region = access_pattern->sz->min;
+ scheme->pattern.max_sz_region = access_pattern->sz->max;
+ scheme->pattern.min_nr_accesses = access_pattern->nr_accesses->min;
+ scheme->pattern.max_nr_accesses = access_pattern->nr_accesses->max;
+ scheme->pattern.min_age_region = access_pattern->age->min;
+ scheme->pattern.max_age_region = access_pattern->age->max;
+
+ scheme->action = sysfs_scheme->action;
+
+ scheme->quota.ms = sysfs_quotas->ms;
+ scheme->quota.sz = sysfs_quotas->sz;
+ scheme->quota.reset_interval = sysfs_quotas->reset_interval_ms;
+ scheme->quota.weight_sz = sysfs_weights->sz;
+ scheme->quota.weight_nr_accesses = sysfs_weights->nr_accesses;
+ scheme->quota.weight_age = sysfs_weights->age;
+
+ scheme->wmarks.metric = sysfs_wmarks->metric;
+ scheme->wmarks.interval = sysfs_wmarks->interval_us;
+ scheme->wmarks.high = sysfs_wmarks->high;
+ scheme->wmarks.mid = sysfs_wmarks->mid;
+ scheme->wmarks.low = sysfs_wmarks->low;
+}
+
static int damon_sysfs_set_schemes(struct damon_ctx *ctx,
struct damon_sysfs_schemes *sysfs_schemes)
{
- int i;
+ struct damos *scheme, *next;
+ int i = 0;
+
+ damon_for_each_scheme_safe(scheme, next, ctx) {
+ if (i < sysfs_schemes->nr)
+ damon_sysfs_update_scheme(scheme,
+ sysfs_schemes->schemes_arr[i]);
+ else
+ damon_destroy_scheme(scheme);
+ i++;
+ }
- for (i = 0; i < sysfs_schemes->nr; i++) {
+ for (; i < sysfs_schemes->nr; i++) {
struct damos *scheme, *next;
scheme = damon_sysfs_mk_scheme(sysfs_schemes->schemes_arr[i]);
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
Possible dependencies:
f268f6cf875f ("mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths")
2ba99c5e0881 ("mm/khugepaged: fix GUP-fast interaction by sending IPI")
8d3c106e19e8 ("mm/khugepaged: take the right locks for page table retraction")
34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE")
58ac9a8993a1 ("mm/khugepaged: attempt to map file/shmem-backed pte-mapped THPs by pmds")
780a4b6fb865 ("mm/khugepaged: check compound_order() in collapse_pte_mapped_thp()")
b26e27015ec9 ("mm: thp: convert to use common struct mm_slot")
685405020b9f ("mm/khugepaged: stop using vma linked list")
7d2c4385c341 ("mm/khugepaged: rename prefix of shared collapse functions")
7d8faaf15545 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse")
507228044236 ("mm/khugepaged: record SCAN_PMD_MAPPED when scan_pmd() finds hugepage")
a7f4e6e4c47c ("mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()")
50ad2f24b3b4 ("mm/khugepaged: propagate enum scan_result codes back to callers")
9710a78ab2ae ("mm/khugepaged: dedup and simplify hugepage alloc and charging")
34d6b470ab9c ("mm/khugepaged: add struct collapse_control")
c6a7f445a272 ("mm: khugepaged: don't carry huge page to the next loop for !CONFIG_NUMA")
1064026bab9f ("mm: khugepaged: reorg some khugepaged helpers")
7da4e2cb8b1f ("mm: thp: kill __transhuge_page_enabled()")
9fec51689ff6 ("mm: thp: kill transparent_hugepage_active()")
f707fa493784 ("mm: khugepaged: better comments for anon vma check in hugepage_vma_revalidate")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f268f6cf875f3220afc77bdd0bf1bb136eb54db9 Mon Sep 17 00:00:00 2001
From: Jann Horn <jannh(a)google.com>
Date: Fri, 25 Nov 2022 22:37:14 +0100
Subject: [PATCH] mm/khugepaged: invoke MMU notifiers in shmem/file collapse
paths
Any codepath that zaps page table entries must invoke MMU notifiers to
ensure that secondary MMUs (like KVM) don't keep accessing pages which
aren't mapped anymore. Secondary MMUs don't hold their own references to
pages that are mirrored over, so failing to notify them can lead to page
use-after-free.
I'm marking this as addressing an issue introduced in commit f3f0e1d2150b
("khugepaged: add support of collapse for tmpfs/shmem pages"), but most of
the security impact of this only came in commit 27e1f8273113 ("khugepaged:
enable collapse pmd for pte-mapped THP"), which actually omitted flushes
for the removal of present PTEs, not just for the removal of empty page
tables.
Link: https://lkml.kernel.org/r/20221129154730.2274278-3-jannh@google.com
Link: https://lkml.kernel.org/r/20221128180252.1684965-3-jannh@google.com
Link: https://lkml.kernel.org/r/20221125213714.4115729-3-jannh@google.com
Fixes: f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages")
Signed-off-by: Jann Horn <jannh(a)google.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Reviewed-by: Yang Shi <shy828301(a)gmail.com>
Cc: John Hubbard <jhubbard(a)nvidia.com>
Cc: Peter Xu <peterx(a)redhat.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 294cb75d9c22..3703a56571c1 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1399,6 +1399,7 @@ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *v
unsigned long addr, pmd_t *pmdp)
{
pmd_t pmd;
+ struct mmu_notifier_range range;
mmap_assert_write_locked(mm);
if (vma->vm_file)
@@ -1410,8 +1411,12 @@ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *v
if (vma->anon_vma)
lockdep_assert_held_write(&vma->anon_vma->root->rwsem);
+ mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, NULL, mm, addr,
+ addr + HPAGE_PMD_SIZE);
+ mmu_notifier_invalidate_range_start(&range);
pmd = pmdp_collapse_flush(vma, addr, pmdp);
tlb_remove_table_sync_one();
+ mmu_notifier_invalidate_range_end(&range);
mm_dec_nr_ptes(mm);
page_table_check_pte_clear_range(mm, addr, pmd);
pte_free(mm, pmd_pgtable(pmd));