The patch titled
Subject: userfaultfd: fix checks for huge PMDs
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
userfaultfd-fix-checks-for-huge-pmds.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Jann Horn <jannh(a)google.com>
Subject: userfaultfd: fix checks for huge PMDs
Date: Tue, 13 Aug 2024 22:25:21 +0200
Patch series "userfaultfd: fix races around pmd_trans_huge() check", v2.
The pmd_trans_huge() code in mfill_atomic() is wrong in three different
ways depending on kernel version:
1. The pmd_trans_huge() check is racy and can lead to a BUG_ON() (if you hit
the right two race windows) - I've tested this in a kernel build with
some extra mdelay() calls. See the commit message for a description
of the race scenario.
On older kernels (before 6.5), I think the same bug can even
theoretically lead to accessing transhuge page contents as a page table
if you hit the right 5 narrow race windows (I haven't tested this case).
2. As pointed out by Qi Zheng, pmd_trans_huge() is not sufficient for
detecting PMDs that don't point to page tables.
On older kernels (before 6.5), you'd just have to win a single fairly
wide race to hit this.
I've tested this on 6.1 stable by racing migration (with a mdelay()
patched into try_to_migrate()) against UFFDIO_ZEROPAGE - on my x86
VM, that causes a kernel oops in ptlock_ptr().
3. On newer kernels (>=6.5), for shmem mappings, khugepaged is allowed
to yank page tables out from under us (though I haven't tested that),
so I think the BUG_ON() checks in mfill_atomic() are just wrong.
I decided to write two separate fixes for these (one fix for bugs 1+2, one
fix for bug 3), so that the first fix can be backported to kernels
affected by bugs 1+2.
This patch (of 2):
This fixes two issues.
I discovered that the following race can occur:
mfill_atomic other thread
============ ============
<zap PMD>
pmdp_get_lockless() [reads none pmd]
<bail if trans_huge>
<if none:>
<pagefault creates transhuge zeropage>
__pte_alloc [no-op]
<zap PMD>
<bail if pmd_trans_huge(*dst_pmd)>
BUG_ON(pmd_none(*dst_pmd))
I have experimentally verified this in a kernel with extra mdelay() calls;
the BUG_ON(pmd_none(*dst_pmd)) triggers.
On kernels newer than commit 0d940a9b270b ("mm/pgtable: allow
pte_offset_map[_lock]() to fail"), this can't lead to anything worse than
a BUG_ON(), since the page table access helpers are actually designed to
deal with page tables concurrently disappearing; but on older kernels
(<=6.4), I think we could probably theoretically race past the two
BUG_ON() checks and end up treating a hugepage as a page table.
The second issue is that, as Qi Zheng pointed out, there are other types
of huge PMDs that pmd_trans_huge() can't catch: devmap PMDs and swap PMDs
(in particular, migration PMDs).
On <=6.4, this is worse than the first issue: If mfill_atomic() runs on a
PMD that contains a migration entry (which just requires winning a single,
fairly wide race), it will pass the PMD to pte_offset_map_lock(), which
assumes that the PMD points to a page table.
Breakage follows: First, the kernel tries to take the PTE lock (which will
crash or maybe worse if there is no "struct page" for the address bits in
the migration entry PMD - I think at least on X86 there usually is no
corresponding "struct page" thanks to the PTE inversion mitigation, amd64
looks different).
If that didn't crash, the kernel would next try to write a PTE into what
it wrongly thinks is a page table.
As part of fixing these issues, get rid of the check for pmd_trans_huge()
before __pte_alloc() - that's redundant, we're going to have to check for
that after the __pte_alloc() anyway.
Backport note: pmdp_get_lockless() is pmd_read_atomic() in older kernels.
Link: https://lkml.kernel.org/r/20240813-uffd-thp-flip-fix-v2-0-5efa61078a41@goog…
Link: https://lkml.kernel.org/r/20240813-uffd-thp-flip-fix-v2-1-5efa61078a41@goog…
Fixes: c1a4de99fada ("userfaultfd: mcopy_atomic|mfill_zeropage: UFFDIO_COPY|UFFDIO_ZEROPAGE preparation")
Signed-off-by: Jann Horn <jannh(a)google.com>
Reported-by: Qi Zheng <zhengqi.arch(a)bytedance.com>
Closes: https://lore.kernel.org/r/59bf3c2e-d58b-41af-ab10-3e631d802229@bytedance.com
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Andrea Arcangeli <aarcange(a)redhat.com>
Cc: Hugh Dickins <hughd(a)google.com>
Cc: Jann Horn <jannh(a)google.com>
Cc: Pavel Emelyanov <xemul(a)virtuozzo.com>
Cc: Qi Zheng <zhengqi.arch(a)bytedance.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/userfaultfd.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
--- a/mm/userfaultfd.c~userfaultfd-fix-checks-for-huge-pmds
+++ a/mm/userfaultfd.c
@@ -787,21 +787,23 @@ retry:
}
dst_pmdval = pmdp_get_lockless(dst_pmd);
- /*
- * If the dst_pmd is mapped as THP don't
- * override it and just be strict.
- */
- if (unlikely(pmd_trans_huge(dst_pmdval))) {
- err = -EEXIST;
- break;
- }
if (unlikely(pmd_none(dst_pmdval)) &&
unlikely(__pte_alloc(dst_mm, dst_pmd))) {
err = -ENOMEM;
break;
}
- /* If an huge pmd materialized from under us fail */
- if (unlikely(pmd_trans_huge(*dst_pmd))) {
+ dst_pmdval = pmdp_get_lockless(dst_pmd);
+ /*
+ * If the dst_pmd is THP don't override it and just be strict.
+ * (This includes the case where the PMD used to be THP and
+ * changed back to none after __pte_alloc().)
+ */
+ if (unlikely(!pmd_present(dst_pmdval) || pmd_trans_huge(dst_pmdval) ||
+ pmd_devmap(dst_pmdval))) {
+ err = -EEXIST;
+ break;
+ }
+ if (unlikely(pmd_bad(dst_pmdval))) {
err = -EFAULT;
break;
}
_
Patches currently in -mm which might be from jannh(a)google.com are
userfaultfd-fix-checks-for-huge-pmds.patch
userfaultfd-dont-bug_on-if-khugepaged-yanks-our-page-table.patch
mm-fix-harmless-type-confusion-in-lock_vma_under_rcu.patch
The patch titled
Subject: mm: vmalloc: ensure vmap_block is initialised before adding to queue
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-vmalloc-ensure-vmap_block-is-initialised-before-adding-to-queue.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Will Deacon <will(a)kernel.org>
Subject: mm: vmalloc: ensure vmap_block is initialised before adding to queue
Date: Mon, 12 Aug 2024 18:16:06 +0100
Commit 8c61291fd850 ("mm: fix incorrect vbq reference in
purge_fragmented_block") extended the 'vmap_block' structure to contain a
'cpu' field which is set at allocation time to the id of the initialising
CPU.
When a new 'vmap_block' is being instantiated by new_vmap_block(), the
partially initialised structure is added to the local 'vmap_block_queue'
xarray before the 'cpu' field has been initialised. If another CPU is
concurrently walking the xarray (e.g. via vm_unmap_aliases()), then it
may perform an out-of-bounds access to the remote queue thanks to an
uninitialised index.
This has been observed as UBSAN errors in Android:
| Internal error: UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP
|
| Call trace:
| purge_fragmented_block+0x204/0x21c
| _vm_unmap_aliases+0x170/0x378
| vm_unmap_aliases+0x1c/0x28
| change_memory_common+0x1dc/0x26c
| set_memory_ro+0x18/0x24
| module_enable_ro+0x98/0x238
| do_init_module+0x1b0/0x310
Move the initialisation of 'vb->cpu' in new_vmap_block() ahead of the
addition to the xarray.
Link: https://lkml.kernel.org/r/20240812171606.17486-1-will@kernel.org
Fixes: 8c61291fd850 ("mm: fix incorrect vbq reference in purge_fragmented_block")
Signed-off-by: Will Deacon <will(a)kernel.org>
Reviewed-by: Baoquan He <bhe(a)redhat.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki(a)gmail.com>
Cc: Zhaoyang Huang <zhaoyang.huang(a)unisoc.com>
Cc: Hailong.Liu <hailong.liu(a)oppo.com>
Cc: Christoph Hellwig <hch(a)infradead.org>
Cc: Lorenzo Stoakes <lstoakes(a)gmail.com>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/vmalloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/vmalloc.c~mm-vmalloc-ensure-vmap_block-is-initialised-before-adding-to-queue
+++ a/mm/vmalloc.c
@@ -2626,6 +2626,7 @@ static void *new_vmap_block(unsigned int
vb->dirty_max = 0;
bitmap_set(vb->used_map, 0, (1UL << order));
INIT_LIST_HEAD(&vb->free_list);
+ vb->cpu = raw_smp_processor_id();
xa = addr_to_vb_xa(va->va_start);
vb_idx = addr_to_vb_idx(va->va_start);
@@ -2642,7 +2643,6 @@ static void *new_vmap_block(unsigned int
* integrity together with list_for_each_rcu from read
* side.
*/
- vb->cpu = raw_smp_processor_id();
vbq = per_cpu_ptr(&vmap_block_queue, vb->cpu);
spin_lock(&vbq->lock);
list_add_tail_rcu(&vb->free_list, &vbq->free);
_
Patches currently in -mm which might be from will(a)kernel.org are
mm-vmalloc-ensure-vmap_block-is-initialised-before-adding-to-queue.patch
The patch titled
Subject: alloc_tag: mark pages reserved during CMA activation as not tagged
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
alloc_tag-mark-pages-reserved-during-cma-activation-as-not-tagged.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Suren Baghdasaryan <surenb(a)google.com>
Subject: alloc_tag: mark pages reserved during CMA activation as not tagged
Date: Tue, 13 Aug 2024 08:07:57 -0700
During CMA activation, pages in CMA area are prepared and then freed
without being allocated. This triggers warnings when memory allocation
debug config (CONFIG_MEM_ALLOC_PROFILING_DEBUG) is enabled. Fix this by
marking these pages not tagged before freeing them.
Link: https://lkml.kernel.org/r/20240813150758.855881-2-surenb@google.com
Fixes: d224eb0287fb ("codetag: debug: mark codetags for reserved pages as empty")
Signed-off-by: Suren Baghdasaryan <surenb(a)google.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Kees Cook <keescook(a)chromium.org>
Cc: Kent Overstreet <kent.overstreet(a)linux.dev>
Cc: Pasha Tatashin <pasha.tatashin(a)soleen.com>
Cc: Sourav Panda <souravpanda(a)google.com>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: <stable(a)vger.kernel.org> [6.10]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/mm_init.c | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/mm_init.c~alloc_tag-mark-pages-reserved-during-cma-activation-as-not-tagged
+++ a/mm/mm_init.c
@@ -2244,6 +2244,8 @@ void __init init_cma_reserved_pageblock(
set_pageblock_migratetype(page, MIGRATE_CMA);
set_page_refcounted(page);
+ /* pages were reserved and not allocated */
+ clear_page_tag_ref(page);
__free_pages(page, pageblock_order);
adjust_managed_page_count(page, pageblock_nr_pages);
_
Patches currently in -mm which might be from surenb(a)google.com are
alloc_tag-introduce-clear_page_tag_ref-helper-function.patch
alloc_tag-mark-pages-reserved-during-cma-activation-as-not-tagged.patch
The patch titled
Subject: alloc_tag: introduce clear_page_tag_ref() helper function
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
alloc_tag-introduce-clear_page_tag_ref-helper-function.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Suren Baghdasaryan <surenb(a)google.com>
Subject: alloc_tag: introduce clear_page_tag_ref() helper function
Date: Tue, 13 Aug 2024 08:07:56 -0700
In several cases we are freeing pages which were not allocated using
common page allocators. For such cases, in order to keep allocation
accounting correct, we should clear the page tag to indicate that the page
being freed is expected to not have a valid allocation tag. Introduce
clear_page_tag_ref() helper function to be used for this.
Link: https://lkml.kernel.org/r/20240813150758.855881-1-surenb@google.com
Fixes: d224eb0287fb ("codetag: debug: mark codetags for reserved pages as empty")
Signed-off-by: Suren Baghdasaryan <surenb(a)google.com>
Suggested-by: David Hildenbrand <david(a)redhat.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Kees Cook <keescook(a)chromium.org>
Cc: Kent Overstreet <kent.overstreet(a)linux.dev>
Cc: Pasha Tatashin <pasha.tatashin(a)soleen.com>
Cc: Sourav Panda <souravpanda(a)google.com>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: <stable(a)vger.kernel.org> [6.10]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
include/linux/pgalloc_tag.h | 13 +++++++++++++
mm/mm_init.c | 10 +---------
mm/page_alloc.c | 9 +--------
3 files changed, 15 insertions(+), 17 deletions(-)
--- a/include/linux/pgalloc_tag.h~alloc_tag-introduce-clear_page_tag_ref-helper-function
+++ a/include/linux/pgalloc_tag.h
@@ -43,6 +43,18 @@ static inline void put_page_tag_ref(unio
page_ext_put(page_ext_from_codetag_ref(ref));
}
+static inline void clear_page_tag_ref(struct page *page)
+{
+ if (mem_alloc_profiling_enabled()) {
+ union codetag_ref *ref = get_page_tag_ref(page);
+
+ if (ref) {
+ set_codetag_empty(ref);
+ put_page_tag_ref(ref);
+ }
+ }
+}
+
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr)
{
@@ -126,6 +138,7 @@ static inline void pgalloc_tag_sub_pages
static inline union codetag_ref *get_page_tag_ref(struct page *page) { return NULL; }
static inline void put_page_tag_ref(union codetag_ref *ref) {}
+static inline void clear_page_tag_ref(struct page *page) {}
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr) {}
static inline void pgalloc_tag_sub(struct page *page, unsigned int nr) {}
--- a/mm/mm_init.c~alloc_tag-introduce-clear_page_tag_ref-helper-function
+++ a/mm/mm_init.c
@@ -2459,15 +2459,7 @@ void __init memblock_free_pages(struct p
}
/* pages were reserved and not allocated */
- if (mem_alloc_profiling_enabled()) {
- union codetag_ref *ref = get_page_tag_ref(page);
-
- if (ref) {
- set_codetag_empty(ref);
- put_page_tag_ref(ref);
- }
- }
-
+ clear_page_tag_ref(page);
__free_pages_core(page, order, MEMINIT_EARLY);
}
--- a/mm/page_alloc.c~alloc_tag-introduce-clear_page_tag_ref-helper-function
+++ a/mm/page_alloc.c
@@ -5815,14 +5815,7 @@ unsigned long free_reserved_area(void *s
void free_reserved_page(struct page *page)
{
- if (mem_alloc_profiling_enabled()) {
- union codetag_ref *ref = get_page_tag_ref(page);
-
- if (ref) {
- set_codetag_empty(ref);
- put_page_tag_ref(ref);
- }
- }
+ clear_page_tag_ref(page);
ClearPageReserved(page);
init_page_count(page);
__free_page(page);
_
Patches currently in -mm which might be from surenb(a)google.com are
alloc_tag-introduce-clear_page_tag_ref-helper-function.patch
alloc_tag-mark-pages-reserved-during-cma-activation-as-not-tagged.patch
The kms paths keep a persistent map active to read and compare the cursor
buffer. These maps can race with each other in simple scenario where:
a) buffer "a" mapped for update
b) buffer "a" mapped for compare
c) do the compare
d) unmap "a" for compare
e) update the cursor
f) unmap "a" for update
At step "e" the buffer has been unmapped and the read contents is bogus.
Prevent unmapping of active read buffers by simply keeping a count of
how many paths have currently active maps and unmap only when the count
reaches 0.
Fixes: 485d98d472d5 ("drm/vmwgfx: Add support for CursorMob and CursorBypass 4")
Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list(a)broadcom.com>
Cc: dri-devel(a)lists.freedesktop.org
Cc: <stable(a)vger.kernel.org> # v5.19+
Signed-off-by: Zack Rusin <zack.rusin(a)broadcom.com>
---
drivers/gpu/drm/vmwgfx/vmwgfx_bo.c | 13 +++++++++++--
drivers/gpu/drm/vmwgfx/vmwgfx_bo.h | 1 +
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
index f42ebc4a7c22..a0e433fbcba6 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
@@ -360,6 +360,8 @@ void *vmw_bo_map_and_cache_size(struct vmw_bo *vbo, size_t size)
void *virtual;
int ret;
+ atomic_inc(&vbo->map_count);
+
virtual = ttm_kmap_obj_virtual(&vbo->map, ¬_used);
if (virtual)
return virtual;
@@ -383,11 +385,17 @@ void *vmw_bo_map_and_cache_size(struct vmw_bo *vbo, size_t size)
*/
void vmw_bo_unmap(struct vmw_bo *vbo)
{
+ int map_count;
+
if (vbo->map.bo == NULL)
return;
- ttm_bo_kunmap(&vbo->map);
- vbo->map.bo = NULL;
+ map_count = atomic_dec_return(&vbo->map_count);
+
+ if (!map_count) {
+ ttm_bo_kunmap(&vbo->map);
+ vbo->map.bo = NULL;
+ }
}
@@ -421,6 +429,7 @@ static int vmw_bo_init(struct vmw_private *dev_priv,
vmw_bo->tbo.priority = 3;
vmw_bo->res_tree = RB_ROOT;
xa_init(&vmw_bo->detached_resources);
+ atomic_set(&vmw_bo->map_count, 0);
params->size = ALIGN(params->size, PAGE_SIZE);
drm_gem_private_object_init(vdev, &vmw_bo->tbo.base, params->size);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h
index 62b4342d5f7c..dc13f1e996c1 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h
@@ -90,6 +90,7 @@ struct vmw_bo {
u32 res_prios[TTM_MAX_BO_PRIORITY];
struct xarray detached_resources;
+ atomic_t map_count;
atomic_t cpu_writers;
/* Not ref-counted. Protected by binding_mutex */
struct vmw_resource *dx_query_ctx;
--
2.43.0
From: Kyle Huey <me(a)kylehuey.com>
The regressing commit is new in 6.10. It assumed that anytime event->prog
is set bpf_overflow_handler() should be invoked to execute the attached bpf
program. This assumption is false for tracing events, and as a result the
regressing commit broke bpftrace by invoking the bpf handler with garbage
inputs on overflow.
Prior to the regression the overflow handlers formed a chain (of length 0,
1, or 2) and perf_event_set_bpf_handler() (the !tracing case) added
bpf_overflow_handler() to that chain, while perf_event_attach_bpf_prog()
(the tracing case) did not. Both set event->prog. The chain of overflow
handlers was replaced by a single overflow handler slot and a fixed call to
bpf_overflow_handler() when appropriate. This modifies the condition there
to check event->prog->type == BPF_PROG_TYPE_PERF_EVENT, restoring the
previous behavior and fixing bpftrace.
Signed-off-by: Kyle Huey <khuey(a)kylehuey.com>
Suggested-by: Andrii Nakryiko <andrii.nakryiko(a)gmail.com>
Reported-by: Joe Damato <jdamato(a)fastly.com>
Closes: https://lore.kernel.org/lkml/ZpFfocvyF3KHaSzF@LQ3V64L9R2/
Fixes: f11f10bfa1ca ("perf/bpf: Call BPF handler directly, not through overflow machinery")
Cc: stable(a)vger.kernel.org
Tested-by: Joe Damato <jdamato(a)fastly.com> # bpftrace
---
v2:
- Update patch based on Andrii's suggestion
- Update commit message
kernel/events/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index aa3450bdc227..c973e3c11e03 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9706,7 +9706,8 @@ static int __perf_event_overflow(struct perf_event *event,
ret = __perf_event_account_interrupt(event, throttle);
- if (event->prog && !bpf_overflow_handler(event, data, regs))
+ if (event->prog && event->prog->type == BPF_PROG_TYPE_PERF_EVENT &&
+ !bpf_overflow_handler(event, data, regs))
return ret;
/*
--
2.25.1
The patch below does not apply to the 4.19-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 8bdd9ef7e9b1b2a73e394712b72b22055e0e26c3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024081222-process-suspect-d983@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
8bdd9ef7e9b1 ("drm/i915/gem: Fix Virtual Memory mapping boundaries calculation")
8e4ee5e87ce6 ("drm/i915: Wrap all access to i915_vma.node.start|size")
3bb6a44251b4 ("drm/i915: Rename ggtt_view as gtt_view")
d976521a995a ("drm/i915: extend i915_vma_pin_iomap()")
d63ddca7c581 ("drm/i915: Update tiled blits selftest")
a0ed9c95cce6 ("drm/i915/gt: Use XY_FAST_COLOR_BLT to clear obj on graphics ver 12+")
fd5803e5eebe ("drm/i915/gt: use engine instance directly for offset")
892bfb8a604d ("drm/i915/fbdev: fixup setting screen_size")
c674c5b9342e ("drm/i915/xehp: CCS should use RCS setup functions")
30b9d1b3ef37 ("drm/i915: add I915_BO_ALLOC_GPU_ONLY")
3312a4ac8a46 ("drm/i915/ttm: require mappable by default")
8fbf28934acf ("drm/i915/ttm: fixup the mock_bo")
db927686e43f ("Merge drm/drm-next into drm-intel-gt-next")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8bdd9ef7e9b1b2a73e394712b72b22055e0e26c3 Mon Sep 17 00:00:00 2001
From: Andi Shyti <andi.shyti(a)linux.intel.com>
Date: Fri, 2 Aug 2024 10:38:50 +0200
Subject: [PATCH] drm/i915/gem: Fix Virtual Memory mapping boundaries
calculation
Calculating the size of the mapped area as the lesser value
between the requested size and the actual size does not consider
the partial mapping offset. This can cause page fault access.
Fix the calculation of the starting and ending addresses, the
total size is now deduced from the difference between the end and
start addresses.
Additionally, the calculations have been rewritten in a clearer
and more understandable form.
Fixes: c58305af1835 ("drm/i915: Use remap_io_mapping() to prefault all PTE in a single pass")
Reported-by: Jann Horn <jannh(a)google.com>
Co-developed-by: Chris Wilson <chris.p.wilson(a)linux.intel.com>
Signed-off-by: Chris Wilson <chris.p.wilson(a)linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti(a)linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen(a)linux.intel.com>
Cc: Matthew Auld <matthew.auld(a)intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi(a)intel.com>
Cc: <stable(a)vger.kernel.org> # v4.9+
Reviewed-by: Jann Horn <jannh(a)google.com>
Reviewed-by: Jonathan Cavitt <Jonathan.cavitt(a)intel.com>
[Joonas: Add Requires: tag]
Requires: 60a2066c5005 ("drm/i915/gem: Adjust vma offset for framebuffer mmap offset")
Signed-off-by: Joonas Lahtinen <joonas.lahtinen(a)linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240802083850.103694-3-andi.…
(cherry picked from commit 97b6784753da06d9d40232328efc5c5367e53417)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen(a)linux.intel.com>
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index ce10dd259812..cac6d4184506 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -290,6 +290,41 @@ static vm_fault_t vm_fault_cpu(struct vm_fault *vmf)
return i915_error_to_vmf_fault(err);
}
+static void set_address_limits(struct vm_area_struct *area,
+ struct i915_vma *vma,
+ unsigned long obj_offset,
+ unsigned long *start_vaddr,
+ unsigned long *end_vaddr)
+{
+ unsigned long vm_start, vm_end, vma_size; /* user's memory parameters */
+ long start, end; /* memory boundaries */
+
+ /*
+ * Let's move into the ">> PAGE_SHIFT"
+ * domain to be sure not to lose bits
+ */
+ vm_start = area->vm_start >> PAGE_SHIFT;
+ vm_end = area->vm_end >> PAGE_SHIFT;
+ vma_size = vma->size >> PAGE_SHIFT;
+
+ /*
+ * Calculate the memory boundaries by considering the offset
+ * provided by the user during memory mapping and the offset
+ * provided for the partial mapping.
+ */
+ start = vm_start;
+ start -= obj_offset;
+ start += vma->gtt_view.partial.offset;
+ end = start + vma_size;
+
+ start = max_t(long, start, vm_start);
+ end = min_t(long, end, vm_end);
+
+ /* Let's move back into the "<< PAGE_SHIFT" domain */
+ *start_vaddr = (unsigned long)start << PAGE_SHIFT;
+ *end_vaddr = (unsigned long)end << PAGE_SHIFT;
+}
+
static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
{
#define MIN_CHUNK_PAGES (SZ_1M >> PAGE_SHIFT)
@@ -302,14 +337,18 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
struct i915_ggtt *ggtt = to_gt(i915)->ggtt;
bool write = area->vm_flags & VM_WRITE;
struct i915_gem_ww_ctx ww;
+ unsigned long obj_offset;
+ unsigned long start, end; /* memory boundaries */
intel_wakeref_t wakeref;
struct i915_vma *vma;
pgoff_t page_offset;
+ unsigned long pfn;
int srcu;
int ret;
- /* We don't use vmf->pgoff since that has the fake offset */
+ obj_offset = area->vm_pgoff - drm_vma_node_start(&mmo->vma_node);
page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT;
+ page_offset += obj_offset;
trace_i915_gem_object_fault(obj, page_offset, true, write);
@@ -402,12 +441,14 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
if (ret)
goto err_unpin;
+ set_address_limits(area, vma, obj_offset, &start, &end);
+
+ pfn = (ggtt->gmadr.start + i915_ggtt_offset(vma)) >> PAGE_SHIFT;
+ pfn += (start - area->vm_start) >> PAGE_SHIFT;
+ pfn += obj_offset - vma->gtt_view.partial.offset;
+
/* Finally, remap it using the new GTT offset */
- ret = remap_io_mapping(area,
- area->vm_start + (vma->gtt_view.partial.offset << PAGE_SHIFT),
- (ggtt->gmadr.start + i915_ggtt_offset(vma)) >> PAGE_SHIFT,
- min_t(u64, vma->size, area->vm_end - area->vm_start),
- &ggtt->iomap);
+ ret = remap_io_mapping(area, start, pfn, end - start, &ggtt->iomap);
if (ret)
goto err_fence;
The patch below does not apply to the 5.15-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>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 89add40066f9ed9abe5f7f886fe5789ff7e0c50e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024081322-yoyo-proving-7a44@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
89add40066f9 ("net: drop bad gso csum_start and offset in virtio_net_hdr")
fc8b2a619469 ("net: more strict VIRTIO_NET_HDR_GSO_UDP_L4 validation")
9840036786d9 ("gso: fix dodgy bit handling for GSO_UDP_L4")
cf9acc90c80e ("net: virtio_net_hdr_to_skb: count transport header in UFO")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 89add40066f9ed9abe5f7f886fe5789ff7e0c50e Mon Sep 17 00:00:00 2001
From: Willem de Bruijn <willemb(a)google.com>
Date: Mon, 29 Jul 2024 16:10:12 -0400
Subject: [PATCH] net: drop bad gso csum_start and offset in virtio_net_hdr
Tighten csum_start and csum_offset checks in virtio_net_hdr_to_skb
for GSO packets.
The function already checks that a checksum requested with
VIRTIO_NET_HDR_F_NEEDS_CSUM is in skb linear. But for GSO packets
this might not hold for segs after segmentation.
Syzkaller demonstrated to reach this warning in skb_checksum_help
offset = skb_checksum_start_offset(skb);
ret = -EINVAL;
if (WARN_ON_ONCE(offset >= skb_headlen(skb)))
By injecting a TSO packet:
WARNING: CPU: 1 PID: 3539 at net/core/dev.c:3284 skb_checksum_help+0x3d0/0x5b0
ip_do_fragment+0x209/0x1b20 net/ipv4/ip_output.c:774
ip_finish_output_gso net/ipv4/ip_output.c:279 [inline]
__ip_finish_output+0x2bd/0x4b0 net/ipv4/ip_output.c:301
iptunnel_xmit+0x50c/0x930 net/ipv4/ip_tunnel_core.c:82
ip_tunnel_xmit+0x2296/0x2c70 net/ipv4/ip_tunnel.c:813
__gre_xmit net/ipv4/ip_gre.c:469 [inline]
ipgre_xmit+0x759/0xa60 net/ipv4/ip_gre.c:661
__netdev_start_xmit include/linux/netdevice.h:4850 [inline]
netdev_start_xmit include/linux/netdevice.h:4864 [inline]
xmit_one net/core/dev.c:3595 [inline]
dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611
__dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261
packet_snd net/packet/af_packet.c:3073 [inline]
The geometry of the bad input packet at tcp_gso_segment:
[ 52.003050][ T8403] skb len=12202 headroom=244 headlen=12093 tailroom=0
[ 52.003050][ T8403] mac=(168,24) mac_len=24 net=(192,52) trans=244
[ 52.003050][ T8403] shinfo(txflags=0 nr_frags=1 gso(size=1552 type=3 segs=0))
[ 52.003050][ T8403] csum(0x60000c7 start=199 offset=1536
ip_summed=3 complete_sw=0 valid=0 level=0)
Mitigate with stricter input validation.
csum_offset: for GSO packets, deduce the correct value from gso_type.
This is already done for USO. Extend it to TSO. Let UFO be:
udp[46]_ufo_fragment ignores these fields and always computes the
checksum in software.
csum_start: finding the real offset requires parsing to the transport
header. Do not add a parser, use existing segmentation parsing. Thanks
to SKB_GSO_DODGY, that also catches bad packets that are hw offloaded.
Again test both TSO and USO. Do not test UFO for the above reason, and
do not test UDP tunnel offload.
GSO packet are almost always CHECKSUM_PARTIAL. USO packets may be
CHECKSUM_NONE since commit 10154dbded6d6 ("udp: Allow GSO transmit
from devices with no checksum offload"), but then still these fields
are initialized correctly in udp4_hwcsum/udp6_hwcsum_outgoing. So no
need to test for ip_summed == CHECKSUM_PARTIAL first.
This revises an existing fix mentioned in the Fixes tag, which broke
small packets with GSO offload, as detected by kselftests.
Link: https://syzkaller.appspot.com/bug?extid=e1db31216c789f552871
Link: https://lore.kernel.org/netdev/20240723223109.2196886-1-kuba@kernel.org
Fixes: e269d79c7d35 ("net: missing check virtio")
Cc: stable(a)vger.kernel.org
Signed-off-by: Willem de Bruijn <willemb(a)google.com>
Link: https://patch.msgid.link/20240729201108.1615114-1-willemdebruijn.kernel@gma…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index d1d7825318c3..6c395a2600e8 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -56,7 +56,6 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
unsigned int thlen = 0;
unsigned int p_off = 0;
unsigned int ip_proto;
- u64 ret, remainder, gso_size;
if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
@@ -99,16 +98,6 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
u32 off = __virtio16_to_cpu(little_endian, hdr->csum_offset);
u32 needed = start + max_t(u32, thlen, off + sizeof(__sum16));
- if (hdr->gso_size) {
- gso_size = __virtio16_to_cpu(little_endian, hdr->gso_size);
- ret = div64_u64_rem(skb->len, gso_size, &remainder);
- if (!(ret && (hdr->gso_size > needed) &&
- ((remainder > needed) || (remainder == 0)))) {
- return -EINVAL;
- }
- skb_shinfo(skb)->tx_flags |= SKBFL_SHARED_FRAG;
- }
-
if (!pskb_may_pull(skb, needed))
return -EINVAL;
@@ -182,6 +171,11 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
if (gso_type != SKB_GSO_UDP_L4)
return -EINVAL;
break;
+ case SKB_GSO_TCPV4:
+ case SKB_GSO_TCPV6:
+ if (skb->csum_offset != offsetof(struct tcphdr, check))
+ return -EINVAL;
+ break;
}
/* Kernel has a special handling for GSO_BY_FRAGS. */
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 4b791e74529e..e4ad3311e148 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -140,6 +140,9 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
if (thlen < sizeof(*th))
goto out;
+ if (unlikely(skb_checksum_start(skb) != skb_transport_header(skb)))
+ goto out;
+
if (!pskb_may_pull(skb, thlen))
goto out;
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index aa2e0a28ca61..bc8a9da750fe 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -278,6 +278,10 @@ struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
if (gso_skb->len <= sizeof(*uh) + mss)
return ERR_PTR(-EINVAL);
+ if (unlikely(skb_checksum_start(gso_skb) !=
+ skb_transport_header(gso_skb)))
+ return ERR_PTR(-EINVAL);
+
if (skb_gso_ok(gso_skb, features | NETIF_F_GSO_ROBUST)) {
/* Packet is from an untrusted source, reset gso_segs. */
skb_shinfo(gso_skb)->gso_segs = DIV_ROUND_UP(gso_skb->len - sizeof(*uh),