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There is a race between xas_split() and xas_load() which can result in
the wrong page being returned, and thus data corruption. Fortunately,
it's hard to hit (syzbot took three months to find it) and often guarded
with VM_BUG_ON().
The anatomy of this race is:
thread A thread B
order-9 page is stored at index 0x200
lookup of page at index 0x274
page split starts
load of sibling entry at offset 9
stores nodes at offsets 8-15
load of entry at offset 8
The entry at offset 8 turns out to be a node, and so we descend into it,
and load the page at index 0x234 instead of 0x274. This is hard to fix
on the split side; we could replace the entire node that contains the
order-9 page instead of replacing the eight entries. Fixing it on
the lookup side is easier; just disallow sibling entries that point
to nodes. This cannot ever be a useful thing as the descent would not
know the correct offset to use within the new node.
The test suite continues to pass, but I have not added a new test for
this bug.
Reported-by: syzbot+cf4cf13056f85dec2c40@syzkaller.appspotmail.com
Tested-by: syzbot+cf4cf13056f85dec2c40@syzkaller.appspotmail.com
Fixes: 6b24ca4a1a8d ("mm: Use multi-index entries in the page cache")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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Turn kmem_cache_alloc() into a wrapper around kmem_cache_alloc_lru().
Fixes: 9bbdc0f32409 ("xarray: use kmem_cache_alloc_lru to allocate xa_node")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Li Wang <liwang@redhat.com>
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Huge vmalloc higher-order backing pages were allocated with __GFP_COMP
in order to allow the sub-pages to be refcounted by callers such as
"remap_vmalloc_page [sic]" (remap_vmalloc_range).
However a similar problem exists for other struct page fields callers
use, for example fb_deferred_io_fault() takes a vmalloc'ed page and
not only refcounts it but uses ->lru, ->mapping, ->index.
This is not compatible with compound sub-pages, and can cause bad page
state issues like
BUG: Bad page state in process swapper/0 pfn:00743
page:(____ptrval____) refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x743
flags: 0x7ffff000000000(node=0|zone=0|lastcpupid=0x7ffff)
raw: 007ffff000000000 c00c00000001d0c8 c00c00000001d0c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: corrupted mapping in tail page
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.18.0-rc3-00082-gfc6fff4a7ce1-dirty #2810
Call Trace:
dump_stack_lvl+0x74/0xa8 (unreliable)
bad_page+0x12c/0x170
free_tail_pages_check+0xe8/0x190
free_pcp_prepare+0x31c/0x4e0
free_unref_page+0x40/0x1b0
__vunmap+0x1d8/0x420
...
The correct approach is to use split high-order pages for the huge
vmalloc backing. These allow callers to treat them in exactly the same
way as individually-allocated order-0 pages.
Link: https://lore.kernel.org/all/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Song Liu <songliubraving@fb.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The pmd_leaf() is used to test a leaf mapped PMD, however, it misses
the PROT_NONE mapped PMD on arm64. Fix it. A real world issue [1]
caused by this was reported by Qian Cai. Also fix pud_leaf().
Link: https://patchwork.kernel.org/comment/24798260/ [1]
Fixes: 8aa82df3c123 ("arm64: mm: add p?d_leaf() definitions")
Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Link: https://lore.kernel.org/r/20220422060033.48711-1-songmuchun@bytedance.com
Signed-off-by: Will Deacon <will@kernel.org>
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In some cases it is possible for mmu_interval_notifier_remove() to race
with mn_tree_inv_end() allowing it to return while the notifier data
structure is still in use. Consider the following sequence:
CPU0 - mn_tree_inv_end() CPU1 - mmu_interval_notifier_remove()
----------------------------------- ------------------------------------
spin_lock(subscriptions->lock);
seq = subscriptions->invalidate_seq;
spin_lock(subscriptions->lock); spin_unlock(subscriptions->lock);
subscriptions->invalidate_seq++;
wait_event(invalidate_seq != seq);
return;
interval_tree_remove(interval_sub); kfree(interval_sub);
spin_unlock(subscriptions->lock);
wake_up_all();
As the wait_event() condition is true it will return immediately. This
can lead to use-after-free type errors if the caller frees the data
structure containing the interval notifier subscription while it is
still on a deferred list. Fix this by taking the appropriate lock when
reading invalidate_seq to ensure proper synchronisation.
I observed this whilst running stress testing during some development.
You do have to be pretty unlucky, but it leads to the usual problems of
use-after-free (memory corruption, kernel crash, difficult to diagnose
WARN_ON, etc).
Link: https://lkml.kernel.org/r/20220420043734.476348-1-apopple@nvidia.com
Fixes: 99cb252f5e68 ("mm/mmu_notifier: add an interval tree notifier")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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vm_insert_page()'s failure is not an unexpected condition, so don't do
WARN_ONCE() in such a case.
Instead, print a kernel message and just return an error code.
This flaw has been reported under an OOM condition by sysbot [1].
The message is mainly for the benefit of the test log, in this case the
fuzzer's log so that humans inspecting the log can figure out what was
going on. KCOV is a testing tool, so I think being a little more chatty
when KCOV unexpectedly is about to fail will save someone debugging
time.
We don't want the WARN, because it's not a kernel bug that syzbot should
report, and failure can happen if the fuzzer tries hard enough (as
above).
Link: https://lkml.kernel.org/r/Ylkr2xrVbhQYwNLf@elver.google.com [1]
Link: https://lkml.kernel.org/r/20220401182512.249282-1-nogikh@google.com
Fixes: b3d7fe86fbd0 ("kcov: properly handle subsequent mmap calls"),
Signed-off-by: Aleksandr Nogikh <nogikh@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add my email address to KASAN reviewers list to make sure that I am
Cc'ed in all the KASAN changes that may affect arm64 MTE.
Link: https://lkml.kernel.org/r/20220419170640.21404-1-vincenzo.frascino@arm.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The pthread struct is allocated on PRIVATE|ANONYMOUS memory [1] which
can be targeted by the oom reaper. This mapping is used to store the
futex robust list head; the kernel does not keep a copy of the robust
list and instead references a userspace address to maintain the
robustness during a process death.
A race can occur between exit_mm and the oom reaper that allows the oom
reaper to free the memory of the futex robust list before the exit path
has handled the futex death:
CPU1 CPU2
--------------------------------------------------------------------
page_fault
do_exit "signal"
wake_oom_reaper
oom_reaper
oom_reap_task_mm (invalidates mm)
exit_mm
exit_mm_release
futex_exit_release
futex_cleanup
exit_robust_list
get_user (EFAULT- can't access memory)
If the get_user EFAULT's, the kernel will be unable to recover the
waiters on the robust_list, leaving userspace mutexes hung indefinitely.
Delay the OOM reaper, allowing more time for the exit path to perform
the futex cleanup.
Reproducer: https://gitlab.com/jsavitz/oom_futex_reproducer
Based on a patch by Michal Hocko.
Link: https://elixir.bootlin.com/glibc/glibc-2.35/source/nptl/allocatestack.c#L370 [1]
Link: https://lkml.kernel.org/r/20220414144042.677008-1-npache@redhat.com
Fixes: 212925802454 ("mm: oom: let oom_reap_task and exit_mmap run concurrently")
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Signed-off-by: Nico Pache <npache@redhat.com>
Co-developed-by: Joel Savitz <jsavitz@redhat.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Herton R. Krzesinski <herton@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joel Savitz <jsavitz@redhat.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Allow the mremap test to be skipped due to errors such as failing to
parse the mmap_min_addr sysctl.
Link: https://lkml.kernel.org/r/20220420215721.4868-4-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Use ksft_test_result_xfail for the tests which are expected to fail.
Link: https://lkml.kernel.org/r/20220420215721.4868-3-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Because mremap does not have a MAP_FIXED_NOREPLACE flag, it can destroy
existing mappings. This causes a segfault when regions such as text are
remapped and the permissions are changed.
Verify the requested mremap destination address does not overlap any
existing mappings by using mmap's MAP_FIXED_NOREPLACE flag. Keep
incrementing the destination address until a valid mapping is found or
fail the current test once the max address is reached.
Link: https://lkml.kernel.org/r/20220420215721.4868-2-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Avoid calling mmap with requested addresses that are less than the
system's mmap_min_addr. When run as root, mmap returns EACCES when
trying to map addresses < mmap_min_addr. This is not one of the error
codes for the condition to retry the mmap in the test.
Rather than arbitrarily retrying on EACCES, don't attempt an mmap until
addr > vm.mmap_min_addr.
Add a munmap call after an alignment check as the mappings are retained
after the retry and can reach the vm.max_map_count sysctl.
Link: https://lkml.kernel.org/r/20220420215721.4868-1-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is a fix for commit f6795053dac8 ("mm: mmap: Allow for "high"
userspace addresses") for hugetlb.
This patch adds support for "high" userspace addresses that are
optionally supported on the system and have to be requested via a hint
mechanism ("high" addr parameter to mmap).
Architectures such as powerpc and x86 achieve this by making changes to
their architectural versions of hugetlb_get_unmapped_area() function.
However, arm64 uses the generic version of that function.
So take into account arch_get_mmap_base() and arch_get_mmap_end() in
hugetlb_get_unmapped_area(). To allow that, move those two macros out
of mm/mmap.c into include/linux/sched/mm.h
If these macros are not defined in architectural code then they default
to (TASK_SIZE) and (base) so should not introduce any behavioural
changes to architectures that do not define them.
For the time being, only ARM64 is affected by this change.
Catalin (ARM64) said
"We should have fixed hugetlb_get_unmapped_area() as well when we added
support for 52-bit VA. The reason for commit f6795053dac8 was to
prevent normal mmap() from returning addresses above 48-bit by default
as some user-space had hard assumptions about this.
It's a slight ABI change if you do this for hugetlb_get_unmapped_area()
but I doubt anyone would notice. It's more likely that the current
behaviour would cause issues, so I'd rather have them consistent.
Basically when arm64 gained support for 52-bit addresses we did not
want user-space calling mmap() to suddenly get such high addresses,
otherwise we could have inadvertently broken some programs (similar
behaviour to x86 here). Hence we added commit f6795053dac8. But we
missed hugetlbfs which could still get such high mmap() addresses. So
in theory that's a potential regression that should have bee addressed
at the same time as commit f6795053dac8 (and before arm64 enabled
52-bit addresses)"
Link: https://lkml.kernel.org/r/ab847b6edb197bffdfe189e70fb4ac76bfe79e0d.1650033747.git.christophe.leroy@csgroup.eu
Fixes: f6795053dac8 ("mm: mmap: Allow for "high" userspace addresses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org> [5.0.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When a PTE is set by UFFD operations such as UFFDIO_COPY, the PTE is
currently only marked as write-protected if the VMA has VM_WRITE flag
set. This seems incorrect or at least would be unexpected by the users.
Consider the following sequence of operations that are being performed
on a certain page:
mprotect(PROT_READ)
UFFDIO_COPY(UFFDIO_COPY_MODE_WP)
mprotect(PROT_READ|PROT_WRITE)
At this point the user would expect to still get UFFD notification when
the page is accessed for write, but the user would not get one, since
the PTE was not marked as UFFD_WP during UFFDIO_COPY.
Fix it by always marking PTEs as UFFD_WP regardless on the
write-permission in the VMA flags.
Link: https://lkml.kernel.org/r/20220217211602.2769-1-namit@vmware.com
Fixes: 292924b26024 ("userfaultfd: wp: apply _PAGE_UFFD_WP bit")
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Daniel Dao has reported [1] a regression on workloads that may trigger a
lot of refaults (anon and file). The underlying issue is that flushing
rstat is expensive. Although rstat flush are batched with (nr_cpus *
MEMCG_BATCH) stat updates, it seems like there are workloads which
genuinely do stat updates larger than batch value within short amount of
time. Since the rstat flush can happen in the performance critical
codepaths like page faults, such workload can suffer greatly.
This patch fixes this regression by making the rstat flushing
conditional in the performance critical codepaths. More specifically,
the kernel relies on the async periodic rstat flusher to flush the stats
and only if the periodic flusher is delayed by more than twice the
amount of its normal time window then the kernel allows rstat flushing
from the performance critical codepaths.
Now the question: what are the side-effects of this change? The worst
that can happen is the refault codepath will see 4sec old lruvec stats
and may cause false (or missed) activations of the refaulted page which
may under-or-overestimate the workingset size. Though that is not very
concerning as the kernel can already miss or do false activations.
There are two more codepaths whose flushing behavior is not changed by
this patch and we may need to come to them in future. One is the
writeback stats used by dirty throttling and second is the deactivation
heuristic in the reclaim. For now keeping an eye on them and if there
is report of regression due to these codepaths, we will reevaluate then.
Link: https://lore.kernel.org/all/CA+wXwBSyO87ZX5PVwdHm-=dBjZYECGmfnydUicUyrQqndgX2MQ@mail.gmail.com [1]
Link: https://lkml.kernel.org/r/20220304184040.1304781-1-shakeelb@google.com
Fixes: 1f828223b799 ("memcg: flush lruvec stats in the refault")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: Daniel Dao <dqminh@cloudflare.com>
Tested-by: Ivan Babrou <ivan@cloudflare.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Frank Hofmann <fhofmann@cloudflare.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Kernel panic when injecting memory_failure for the global
huge_zero_page, when CONFIG_DEBUG_VM is enabled, as follows.
Injecting memory failure for pfn 0x109ff9 at process virtual address 0x20ff9000
page:00000000fb053fc3 refcount:2 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109e00
head:00000000fb053fc3 order:9 compound_mapcount:0 compound_pincount:0
flags: 0x17fffc000010001(locked|head|node=0|zone=2|lastcpupid=0x1ffff)
raw: 017fffc000010001 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000002ffffffff 0000000000000000
page dumped because: VM_BUG_ON_PAGE(is_huge_zero_page(head))
------------[ cut here ]------------
kernel BUG at mm/huge_memory.c:2499!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 6 PID: 553 Comm: split_bug Not tainted 5.18.0-rc1+ #11
Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 3288b3c 04/01/2014
RIP: 0010:split_huge_page_to_list+0x66a/0x880
Code: 84 9b fb ff ff 48 8b 7c 24 08 31 f6 e8 9f 5d 2a 00 b8 b8 02 00 00 e9 e8 fb ff ff 48 c7 c6 e8 47 3c 82 4c b
RSP: 0018:ffffc90000dcbdf8 EFLAGS: 00010246
RAX: 000000000000003c RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff823e4c4f RDI: 00000000ffffffff
RBP: ffff88843fffdb40 R08: 0000000000000000 R09: 00000000fffeffff
R10: ffffc90000dcbc48 R11: ffffffff82d68448 R12: ffffea0004278000
R13: ffffffff823c6203 R14: 0000000000109ff9 R15: ffffea000427fe40
FS: 00007fc375a26740(0000) GS:ffff88842fd80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc3757c9290 CR3: 0000000102174006 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
try_to_split_thp_page+0x3a/0x130
memory_failure+0x128/0x800
madvise_inject_error.cold+0x8b/0xa1
__x64_sys_madvise+0x54/0x60
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc3754f8bf9
Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 8
RSP: 002b:00007ffeda93a1d8 EFLAGS: 00000217 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc3754f8bf9
RDX: 0000000000000064 RSI: 0000000000003000 RDI: 0000000020ff9000
RBP: 00007ffeda93a200 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000217 R12: 0000000000400490
R13: 00007ffeda93a2e0 R14: 0000000000000000 R15: 0000000000000000
This makes huge_zero_page bail out explicitly before split in
memory_failure(), thus the panic above won't happen again.
Link: https://lkml.kernel.org/r/497d3835612610e370c74e697ea3c721d1d55b9c.1649775850.git.xuyu@linux.alibaba.com
Fixes: 6a46079cf57a ("HWPOISON: The high level memory error handler in the VM v7")
Signed-off-by: Xu Yu <xuyu@linux.alibaba.com>
Reported-by: Abaci <abaci@linux.alibaba.com>
Suggested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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There is a race condition between memory_failure_hugetlb() and hugetlb
free/demotion, which causes setting PageHWPoison flag on the wrong page.
The one simple result is that wrong processes can be killed, but another
(more serious) one is that the actual error is left unhandled, so no one
prevents later access to it, and that might lead to more serious results
like consuming corrupted data.
Think about the below race window:
CPU 1 CPU 2
memory_failure_hugetlb
struct page *head = compound_head(p);
hugetlb page might be freed to
buddy, or even changed to another
compound page.
get_hwpoison_page -- page is not what we want now...
The current code first does prechecks roughly and then reconfirms after
taking refcount, but it's found that it makes code overly complicated,
so move the prechecks in a single hugetlb_lock range.
A newly introduced function, try_memory_failure_hugetlb(), always takes
hugetlb_lock (even for non-hugetlb pages). That can be improved, but
memory_failure() is rare in principle, so should not be a big problem.
Link: https://lkml.kernel.org/r/20220408135323.1559401-2-naoya.horiguchi@linux.dev
Fixes: 761ad8d7c7b5 ("mm: hwpoison: introduce memory_failure_hugetlb()")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Before detecting the cable type on the dma bar, the driver should check
whether the 'bmdma_addr' is zero, which means the adapter does not
support DMA, otherwise we will get the following error:
[ 5.146634] Bad IO access at port 0x1 (return inb(port))
[ 5.147206] WARNING: CPU: 2 PID: 303 at lib/iomap.c:44 ioread8+0x4a/0x60
[ 5.150856] RIP: 0010:ioread8+0x4a/0x60
[ 5.160238] Call Trace:
[ 5.160470] <TASK>
[ 5.160674] marvell_cable_detect+0x6e/0xc0 [pata_marvell]
[ 5.161728] ata_eh_recover+0x3520/0x6cc0
[ 5.168075] ata_do_eh+0x49/0x3c0
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
|
|
There can be lots of build errors when building cpuidle-riscv-sbi.o.
They are all caused by a kconfig problem with this warning:
WARNING: unmet direct dependencies detected for RISCV_SBI_CPUIDLE
Depends on [n]: CPU_IDLE [=y] && RISCV [=y] && RISCV_SBI [=n]
Selected by [y]:
- SOC_VIRT [=y] && CPU_IDLE [=y]
so make the 'select' of RISCV_SBI_CPUIDLE also depend on RISCV_SBI.
Fixes: c5179ef1ca0c ("RISC-V: Enable RISC-V SBI CPU Idle driver for QEMU virt machine")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
When Sv57 is not available the satp.MODE test in set_satp_mode() will
fail and lead to pgdir re-programming for Sv48. The pgdir re-programming
will fail as well due to pre-existing pgdir entry used for Sv57 and as
a result kernel fails to boot on RISC-V platform not having Sv57.
To fix above issue, we should clear the pgdir memory in set_satp_mode()
before re-programming.
Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
Reported-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
|
|
Clean up code that was hardcoding masks for various fields,
now that the masks are included in processor.h.
For more cleanup, define PAGE_SIZE and PAGE_MASK just like in Linux.
PAGE_SIZE in particular was defined by several tests.
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Red Hat's QE team reported test failure on access_tracking_perf_test:
Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages
guest physical test memory offset: 0x3fffbffff000
Populating memory : 0.684014577s
Writing to populated memory : 0.006230175s
Reading from populated memory : 0.004557805s
==== Test Assertion Failure ====
lib/kvm_util.c:1411: false
pid=125806 tid=125809 errno=4 - Interrupted system call
1 0x0000000000402f7c: addr_gpa2hva at kvm_util.c:1411
2 (inlined by) addr_gpa2hva at kvm_util.c:1405
3 0x0000000000401f52: lookup_pfn at access_tracking_perf_test.c:98
4 (inlined by) mark_vcpu_memory_idle at access_tracking_perf_test.c:152
5 (inlined by) vcpu_thread_main at access_tracking_perf_test.c:232
6 0x00007fefe9ff81ce: ?? ??:0
7 0x00007fefe9c64d82: ?? ??:0
No vm physical memory at 0xffbffff000
I can easily reproduce it with a Intel(R) Xeon(R) CPU E5-2630 with 46 bits
PA.
It turns out that the address translation for clearing idle page tracking
returned a wrong result; addr_gva2gpa()'s last step, which is based on
"pte[index[0]].pfn", did the calculation with 40 bits length and the
high 12 bits got truncated. In above case the GPA address to be returned
should be 0x3fffbffff000 for GVA 0xc0000000, but it got truncated into
0xffbffff000 and the subsequent gpa2hva lookup failed.
The width of operations on bit fields greater than 32-bit is
implementation defined, and differs between GCC (which uses the bitfield
precision) and clang (which uses 64-bit arithmetic), so this is a
potential minefield. Remove the bit fields and using manual masking
instead.
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2075036
Reported-by: Nana Liu <nanliu@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Flush the CPU caches when memory is reclaimed from an SEV guest (where
reclaim also includes it being unmapped from KVM's memslots). Due to lack
of coherency for SEV encrypted memory, failure to flush results in silent
data corruption if userspace is malicious/broken and doesn't ensure SEV
guest memory is properly pinned and unpinned.
Cache coherency is not enforced across the VM boundary in SEV (AMD APM
vol.2 Section 15.34.7). Confidential cachelines, generated by confidential
VM guests have to be explicitly flushed on the host side. If a memory page
containing dirty confidential cachelines was released by VM and reallocated
to another user, the cachelines may corrupt the new user at a later time.
KVM takes a shortcut by assuming all confidential memory remain pinned
until the end of VM lifetime. Therefore, KVM does not flush cache at
mmu_notifier invalidation events. Because of this incorrect assumption and
the lack of cache flushing, malicous userspace can crash the host kernel:
creating a malicious VM and continuously allocates/releases unpinned
confidential memory pages when the VM is running.
Add cache flush operations to mmu_notifier operations to ensure that any
physical memory leaving the guest VM get flushed. In particular, hook
mmu_notifier_invalidate_range_start and mmu_notifier_release events and
flush cache accordingly. The hook after releasing the mmu lock to avoid
contention with other vCPUs.
Cc: stable@vger.kernel.org
Suggested-by: Sean Christpherson <seanjc@google.com>
Reported-by: Mingwei Zhang <mizhang@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Message-Id: <20220421031407.2516575-4-mizhang@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Fixes headset detection on Clevo NP70PNP.
Signed-off-by: Tim Crawford <tcrawford@system76.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220421170412.3697-1-tcrawford@system76.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
Add RaptorLake-P PCI IDs
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Gongjun Song <gongjun.song@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220421163546.319604-1-pierre-louis.bossart@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
Use clflush_cache_range() to flush the confidential memory when
SME_COHERENT is supported in AMD CPU. Cache flush is still needed since
SME_COHERENT only support cache invalidation at CPU side. All confidential
cache lines are still incoherent with DMA devices.
Cc: stable@vger.kerel.org
Fixes: add5e2f04541 ("KVM: SVM: Add support for the SEV-ES VMSA")
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Message-Id: <20220421031407.2516575-3-mizhang@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Rework sev_flush_guest_memory() to explicitly handle only a single page,
and harden it to fall back to WBINVD if VM_PAGE_FLUSH fails. Per-page
flushing is currently used only to flush the VMSA, and in its current
form, the helper is completely broken with respect to flushing actual
guest memory, i.e. won't work correctly for an arbitrary memory range.
VM_PAGE_FLUSH takes a host virtual address, and is subject to normal page
walks, i.e. will fault if the address is not present in the host page
tables or does not have the correct permissions. Current AMD CPUs also
do not honor SMAP overrides (undocumented in kernel versions of the APM),
so passing in a userspace address is completely out of the question. In
other words, KVM would need to manually walk the host page tables to get
the pfn, ensure the pfn is stable, and then use the direct map to invoke
VM_PAGE_FLUSH. And the latter might not even work, e.g. if userspace is
particularly evil/clever and backs the guest with Secret Memory (which
unmaps memory from the direct map).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Fixes: add5e2f04541 ("KVM: SVM: Add support for the SEV-ES VMSA")
Reported-by: Mingwei Zhang <mizhang@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Message-Id: <20220421031407.2516575-2-mizhang@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
When compiling kvm_page_table_test.c, I get this compiler warning
with gcc 11.2:
kvm_page_table_test.c: In function 'pre_init_before_test':
../../../../tools/include/linux/kernel.h:44:24: warning: comparison of
distinct pointer types lacks a cast
44 | (void) (&_max1 == &_max2); \
| ^~
kvm_page_table_test.c:281:21: note: in expansion of macro 'max'
281 | alignment = max(0x100000, alignment);
| ^~~
Fix it by adjusting the type of the absolute value.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-Id: <20220414103031.565037-1-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
NMI-watchdog is one of the favorite features of kernel developers,
but it does not work in AMD guest even with vPMU enabled and worse,
the system misrepresents this capability via /proc.
This is a PMC emulation error. KVM does not pass the latest valid
value to perf_event in time when guest NMI-watchdog is running, thus
the perf_event corresponding to the watchdog counter will enter the
old state at some point after the first guest NMI injection, forcing
the hardware register PMC0 to be constantly written to 0x800000000001.
Meanwhile, the running counter should accurately reflect its new value
based on the latest coordinated pmc->counter (from vPMC's point of view)
rather than the value written directly by the guest.
Fixes: 168d918f2643 ("KVM: x86: Adjust counter sample period after a wrmsr")
Reported-by: Dongli Cao <caodongli@kingsoft.com>
Signed-off-by: Like Xu <likexu@tencent.com>
Reviewed-by: Yanan Wang <wangyanan55@huawei.com>
Tested-by: Yanan Wang <wangyanan55@huawei.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20220409015226.38619-1-likexu@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
MSR_KVM_POLL_CONTROL is cleared on reset, thus reverting guests to
host-side polling after suspend/resume. Non-bootstrap CPUs are
restored correctly by the haltpoll driver because they are hot-unplugged
during suspend and hot-plugged during resume; however, the BSP
is not hotpluggable and remains in host-sde polling mode after
the guest resume. The makes the guest pay for the cost of vmexits
every time the guest enters idle.
Fix it by recording BSP's haltpoll state and resuming it during guest
resume.
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1650267752-46796-1-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
SPDX comments use use /* */ style comments in headers anad
// style comments in .c files. Also fix two spelling mistakes.
Signed-off-by: Tom Rix <trix@redhat.com>
Message-Id: <20220410153840.55506-1-trix@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Skip the APICv inhibit update for KVM_GUESTDBG_BLOCKIRQ if APICv is
disabled at the module level to avoid having to acquire the mutex and
potentially process all vCPUs. The DISABLE inhibit will (barring bugs)
never be lifted, so piling on more inhibits is unnecessary.
Fixes: cae72dcc3b21 ("KVM: x86: inhibit APICv when KVM_GUESTDBG_BLOCKIRQ active")
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220420013732.3308816-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Make a KVM_REQ_APICV_UPDATE request when creating a vCPU with an
in-kernel local APIC and APICv enabled at the module level. Consuming
kvm_apicv_activated() and stuffing vcpu->arch.apicv_active directly can
race with __kvm_set_or_clear_apicv_inhibit(), as vCPU creation happens
before the vCPU is fully onlined, i.e. it won't get the request made to
"all" vCPUs. If APICv is globally inhibited between setting apicv_active
and onlining the vCPU, the vCPU will end up running with APICv enabled
and trigger KVM's sanity check.
Mark APICv as active during vCPU creation if APICv is enabled at the
module level, both to be optimistic about it's final state, e.g. to avoid
additional VMWRITEs on VMX, and because there are likely bugs lurking
since KVM checks apicv_active in multiple vCPU creation paths. While
keeping the current behavior of consuming kvm_apicv_activated() is
arguably safer from a regression perspective, force apicv_active so that
vCPU creation runs with deterministic state and so that if there are bugs,
they are found sooner than later, i.e. not when some crazy race condition
is hit.
WARNING: CPU: 0 PID: 484 at arch/x86/kvm/x86.c:9877 vcpu_enter_guest+0x2ae3/0x3ee0 arch/x86/kvm/x86.c:9877
Modules linked in:
CPU: 0 PID: 484 Comm: syz-executor361 Not tainted 5.16.13 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1~cloud0 04/01/2014
RIP: 0010:vcpu_enter_guest+0x2ae3/0x3ee0 arch/x86/kvm/x86.c:9877
Call Trace:
<TASK>
vcpu_run arch/x86/kvm/x86.c:10039 [inline]
kvm_arch_vcpu_ioctl_run+0x337/0x15e0 arch/x86/kvm/x86.c:10234
kvm_vcpu_ioctl+0x4d2/0xc80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3727
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x16d/0x1d0 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
The bug was hit by a syzkaller spamming VM creation with 2 vCPUs and a
call to KVM_SET_GUEST_DEBUG.
r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x0, 0x0)
r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)
ioctl$KVM_CAP_SPLIT_IRQCHIP(r1, 0x4068aea3, &(0x7f0000000000)) (async)
r2 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x0) (async)
r3 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x400000000000002)
ioctl$KVM_SET_GUEST_DEBUG(r3, 0x4048ae9b, &(0x7f00000000c0)={0x5dda9c14aa95f5c5})
ioctl$KVM_RUN(r2, 0xae80, 0x0)
Reported-by: Gaoning Pan <pgn@zju.edu.cn>
Reported-by: Yongkang Jia <kangel@zju.edu.cn>
Fixes: 8df14af42f00 ("kvm: x86: Add support for dynamic APICv activation")
Cc: stable@vger.kernel.org
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220420013732.3308816-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Defer APICv updates that occur while L2 is active until nested VM-Exit,
i.e. until L1 regains control. vmx_refresh_apicv_exec_ctrl() assumes L1
is active and (a) stomps all over vmcs02 and (b) neglects to ever updated
vmcs01. E.g. if vmcs12 doesn't enable the TPR shadow for L2 (and thus no
APICv controls), L1 performs nested VM-Enter APICv inhibited, and APICv
becomes unhibited while L2 is active, KVM will set various APICv controls
in vmcs02 and trigger a failed VM-Entry. The kicker is that, unless
running with nested_early_check=1, KVM blames L1 and chaos ensues.
In all cases, ignoring vmcs02 and always deferring the inhibition change
to vmcs01 is correct (or at least acceptable). The ABSENT and DISABLE
inhibitions cannot truly change while L2 is active (see below).
IRQ_BLOCKING can change, but it is firmly a best effort debug feature.
Furthermore, only L2's APIC is accelerated/virtualized to the full extent
possible, e.g. even if L1 passes through its APIC to L2, normal MMIO/MSR
interception will apply to the virtual APIC managed by KVM.
The exception is the SELF_IPI register when x2APIC is enabled, but that's
an acceptable hole.
Lastly, Hyper-V's Auto EOI can technically be toggled if L1 exposes the
MSRs to L2, but for that to work in any sane capacity, L1 would need to
pass through IRQs to L2 as well, and IRQs must be intercepted to enable
virtual interrupt delivery. I.e. exposing Auto EOI to L2 and enabling
VID for L2 are, for all intents and purposes, mutually exclusive.
Lack of dynamic toggling is also why this scenario is all but impossible
to encounter in KVM's current form. But a future patch will pend an
APICv update request _during_ vCPU creation to plug a race where a vCPU
that's being created doesn't get included in the "all vCPUs request"
because it's not yet visible to other vCPUs. If userspaces restores L2
after VM creation (hello, KVM selftests), the first KVM_RUN will occur
while L2 is active and thus service the APICv update request made during
VM creation.
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220420013732.3308816-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Set the DISABLE inhibit, not the ABSENT inhibit, if APICv is disabled via
module param. A recent refactoring to add a wrapper for setting/clearing
inhibits unintentionally changed the flag, probably due to a copy+paste
goof.
Fixes: 4f4c4a3ee53c ("KVM: x86: Trace all APICv inhibit changes and capture overall status")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220420013732.3308816-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Initialize debugfs_entry to its semi-magical -ENOENT value when the VM
is created. KVM's teardown when VM creation fails is kludgy and calls
kvm_uevent_notify_change() and kvm_destroy_vm_debugfs() even if KVM never
attempted kvm_create_vm_debugfs(). Because debugfs_entry is zero
initialized, the IS_ERR() checks pass and KVM derefs a NULL pointer.
BUG: kernel NULL pointer dereference, address: 0000000000000018
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 1068b1067 P4D 1068b1067 PUD 1068b0067 PMD 0
Oops: 0000 [#1] SMP
CPU: 0 PID: 871 Comm: repro Not tainted 5.18.0-rc1+ #825
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:__dentry_path+0x7b/0x130
Call Trace:
<TASK>
dentry_path_raw+0x42/0x70
kvm_uevent_notify_change.part.0+0x10c/0x200 [kvm]
kvm_put_kvm+0x63/0x2b0 [kvm]
kvm_dev_ioctl+0x43a/0x920 [kvm]
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x31/0x50
entry_SYSCALL_64_after_hwframe+0x44/0xae
</TASK>
Modules linked in: kvm_intel kvm irqbypass
Fixes: a44a4cc1c969 ("KVM: Don't create VM debugfs files outside of the VM directory")
Cc: stable@vger.kernel.org
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@google.com>
Reported-by: syzbot+df6fbbd2ee39f21289ef@syzkaller.appspotmail.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Message-Id: <20220415004622.2207751-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Add wrappers to acquire/release KVM's SRCU lock when stashing the index
in vcpu->src_idx, along with rudimentary detection of illegal usage,
e.g. re-acquiring SRCU and thus overwriting vcpu->src_idx. Because the
SRCU index is (currently) either 0 or 1, illegal nesting bugs can go
unnoticed for quite some time and only cause problems when the nested
lock happens to get a different index.
Wrap the WARNs in PROVE_RCU=y, and make them ONCE, otherwise KVM will
likely yell so loudly that it will bring the kernel to its knees.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20220415004343.2203171-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Use the generic kvm_vcpu's srcu_idx instead of using an indentical field
in RISC-V's version of kvm_vcpu_arch. Generic KVM very intentionally
does not touch vcpu->srcu_idx, i.e. there's zero chance of running afoul
of common code.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220415004343.2203171-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Don't re-acquire SRCU in complete_emulated_io() now that KVM acquires the
lock in kvm_arch_vcpu_ioctl_run(). More importantly, don't overwrite
vcpu->srcu_idx. If the index acquired by complete_emulated_io() differs
from the one acquired by kvm_arch_vcpu_ioctl_run(), KVM will effectively
leak a lock and hang if/when synchronize_srcu() is invoked for the
relevant grace period.
Fixes: 8d25b7beca7e ("KVM: x86: pull kvm->srcu read-side to kvm_arch_vcpu_ioctl_run")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220415004343.2203171-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
After mnt_hold_writers() has been called we will always have set MNT_WRITE_HOLD
and consequently we always need to pair mnt_hold_writers() with
mnt_unhold_writers(). After the recent cleanup in [1] where Al switched from a
do-while to a for loop the cleanup currently fails to unset MNT_WRITE_HOLD for
the first mount that was changed. Fix this and make sure that the first mount
will be cleaned up and add some comments to make it more obvious.
Link: https://lore.kernel.org/lkml/0000000000007cc21d05dd0432b8@google.com
Link: https://lore.kernel.org/lkml/00000000000080e10e05dd043247@google.com
Link: https://lore.kernel.org/r/20220420131925.2464685-1-brauner@kernel.org
Fixes: e257039f0fc7 ("mount_setattr(): clean the control flow and calling conventions") [1]
Cc: Hillf Danton <hdanton@sina.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: syzbot+10a16d1c43580983f6a2@syzkaller.appspotmail.com
Reported-by: syzbot+306090cfa3294f0bbfb3@syzkaller.appspotmail.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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There is a deadlock in rr_close(), which is shown below:
(Thread 1) | (Thread 2)
| rr_open()
rr_close() | add_timer()
spin_lock_irqsave() //(1) | (wait a time)
... | rr_timer()
del_timer_sync() | spin_lock_irqsave() //(2)
(wait timer to stop) | ...
We hold rrpriv->lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need rrpriv->lock in position (2) of thread 2.
As a result, rr_close() will block forever.
This patch extracts del_timer_sync() from the protection of
spin_lock_irqsave(), which could let timer handler to obtain
the needed lock.
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Link: https://lore.kernel.org/r/20220417125519.82618-1-duoming@zju.edu.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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On HP EliteBook 845 G9 and EliteBook 865 G9, the audio LEDs can be enabled by
ALC285_FIXUP_HP_MUTE_LED. So use it accordingly.
Signed-off-by: Andy Chi <andy.chi@canonical.com>
Fixes: 07bcab93946c ("ALSA: hda/realtek: Add support for HP Laptops")
Link: https://lore.kernel.org/r/20220421063606.39772-1-andy.chi@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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because the copychunk_write might cover a region of the file that has not yet
been sent to the server and thus fail.
A simple way to reproduce this is:
truncate -s 0 /mnt/testfile; strace -f -o x -ttT xfs_io -i -f -c 'pwrite 0k 128k' -c 'fcollapse 16k 24k' /mnt/testfile
the issue is that the 'pwrite 0k 128k' becomes rearranged on the wire with
the 'fcollapse 16k 24k' due to write-back caching.
fcollapse is implemented in cifs.ko as a SMB2 IOCTL(COPYCHUNK_WRITE) call
and it will fail serverside since the file is still 0b in size serverside
until the writes have been destaged.
To avoid this we must ensure that we destage any unwritten data to the
server before calling COPYCHUNK_WRITE.
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1997373
Reported-by: Xiaoli Feng <xifeng@redhat.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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TCP_Server_Info::origin_fullpath and TCP_Server_Info::leaf_fullpath
are protected by refpath_lock mutex and not cifs_tcp_ses_lock
spinlock.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Either mount(2) or automount might not have server->origin_fullpath
set yet while refresh_cache_worker() is attempting to refresh DFS
referrals. Add missing NULL check and locking around it.
This fixes bellow crash:
[ 1070.276835] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
[ 1070.277676] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[ 1070.278219] CPU: 1 PID: 8506 Comm: kworker/u8:1 Not tainted 5.18.0-rc3 #10
[ 1070.278701] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[ 1070.279495] Workqueue: cifs-dfscache refresh_cache_worker [cifs]
[ 1070.280044] RIP: 0010:strcasecmp+0x34/0x150
[ 1070.280359] Code: 00 00 00 fc ff df 41 54 55 48 89 fd 53 48 83 ec 10 eb 03 4c 89 fe 48 89 ef 48 83 c5 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 bc 00 00 00 0f b6 45 ff 44
[ 1070.281729] RSP: 0018:ffffc90008367958 EFLAGS: 00010246
[ 1070.282114] RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
[ 1070.282691] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 1070.283273] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff873eda27
[ 1070.283857] R10: ffffc900083679a0 R11: 0000000000000001 R12: ffff88812624c000
[ 1070.284436] R13: dffffc0000000000 R14: ffff88810e6e9a88 R15: ffff888119bb9000
[ 1070.284990] FS: 0000000000000000(0000) GS:ffff888151200000(0000) knlGS:0000000000000000
[ 1070.285625] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1070.286100] CR2: 0000561a4d922418 CR3: 000000010aecc000 CR4: 0000000000350ee0
[ 1070.286683] Call Trace:
[ 1070.286890] <TASK>
[ 1070.287070] refresh_cache_worker+0x895/0xd20 [cifs]
[ 1070.287475] ? __refresh_tcon.isra.0+0xfb0/0xfb0 [cifs]
[ 1070.287905] ? __lock_acquire+0xcd1/0x6960
[ 1070.288247] ? is_dynamic_key+0x1a0/0x1a0
[ 1070.288591] ? lockdep_hardirqs_on_prepare+0x410/0x410
[ 1070.289012] ? lock_downgrade+0x6f0/0x6f0
[ 1070.289318] process_one_work+0x7bd/0x12d0
[ 1070.289637] ? worker_thread+0x160/0xec0
[ 1070.289970] ? pwq_dec_nr_in_flight+0x230/0x230
[ 1070.290318] ? _raw_spin_lock_irq+0x5e/0x90
[ 1070.290619] worker_thread+0x5ac/0xec0
[ 1070.290891] ? process_one_work+0x12d0/0x12d0
[ 1070.291199] kthread+0x2a5/0x350
[ 1070.291430] ? kthread_complete_and_exit+0x20/0x20
[ 1070.291770] ret_from_fork+0x22/0x30
[ 1070.292050] </TASK>
[ 1070.292223] Modules linked in: bpfilter cifs cifs_arc4 cifs_md4
[ 1070.292765] ---[ end trace 0000000000000000 ]---
[ 1070.293108] RIP: 0010:strcasecmp+0x34/0x150
[ 1070.293471] Code: 00 00 00 fc ff df 41 54 55 48 89 fd 53 48 83 ec 10 eb 03 4c 89 fe 48 89 ef 48 83 c5 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 bc 00 00 00 0f b6 45 ff 44
[ 1070.297718] RSP: 0018:ffffc90008367958 EFLAGS: 00010246
[ 1070.298622] RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
[ 1070.299428] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 1070.300296] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff873eda27
[ 1070.301204] R10: ffffc900083679a0 R11: 0000000000000001 R12: ffff88812624c000
[ 1070.301932] R13: dffffc0000000000 R14: ffff88810e6e9a88 R15: ffff888119bb9000
[ 1070.302645] FS: 0000000000000000(0000) GS:ffff888151200000(0000) knlGS:0000000000000000
[ 1070.303462] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1070.304131] CR2: 0000561a4d922418 CR3: 000000010aecc000 CR4: 0000000000350ee0
[ 1070.305004] Kernel panic - not syncing: Fatal exception
[ 1070.305711] Kernel Offset: disabled
[ 1070.305971] ---[ end Kernel panic - not syncing: Fatal exception ]---
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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|
This reverts commit 5a519c8fe4d620912385f94372fc8472fa98c662.
It turns out that making the pipe almost arbitrarily large has some
rather unexpected downsides. The kernel test robot reports a kernel
warning that is due to pipe->max_usage now growing to the point where
the iter_file_splice_write() buffer allocation can no longer be
satisfied as a slab allocation, and the
int nbufs = pipe->max_usage;
struct bio_vec *array = kcalloc(nbufs, sizeof(struct bio_vec),
GFP_KERNEL);
code sequence there will now always fail as a result.
That code could be modified to use kvcalloc() too, but I feel very
uncomfortable making those kinds of changes for a very niche use case
that really should have other options than make these kinds of
fundamental changes to pipe behavior.
Maybe the CRIU process dumping should be multi-threaded, and use
multiple pipes and multiple cores, rather than try to use one larger
pipe to minimize splice() calls.
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/all/20220420073717.GD16310@xsang-OptiPlex-9020/
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The first "if" condition in __memcpy_flushcache is supposed to align the
"dest" variable to 8 bytes and copy data up to this alignment. However,
this condition may misbehave if "size" is greater than 4GiB.
The statement min_t(unsigned, size, ALIGN(dest, 8) - dest); casts both
arguments to unsigned int and selects the smaller one. However, the
cast truncates high bits in "size" and it results in misbehavior.
For example:
suppose that size == 0x100000001, dest == 0x200000002
min_t(unsigned, size, ALIGN(dest, 8) - dest) == min_t(0x1, 0xe) == 0x1;
...
dest += 0x1;
so we copy just one byte "and" dest remains unaligned.
This patch fixes the bug by replacing unsigned with size_t.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The test verifies that packets are correctly flooded by the bridge and
the VXLAN device by matching on the encapsulated packets at the other
end. However, if packets other than those generated by the test also
ingress the bridge (e.g., MLD packets), they will be flooded as well and
interfere with the expected count.
Make the test more robust by making sure that only the packets generated
by the test can ingress the bridge. Drop all the rest using tc filters
on the egress of 'br0' and 'h1'.
In the software data path, the problem can be solved by matching on the
inner destination MAC or dropping unwanted packets at the egress of the
VXLAN device, but this is not currently supported by mlxsw.
Fixes: d01724dd2a66 ("selftests: mlxsw: spectrum-2: Add a test for VxLAN flooding with IPv6")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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|
The test verifies that packets are correctly flooded by the bridge and
the VXLAN device by matching on the encapsulated packets at the other
end. However, if packets other than those generated by the test also
ingress the bridge (e.g., MLD packets), they will be flooded as well and
interfere with the expected count.
Make the test more robust by making sure that only the packets generated
by the test can ingress the bridge. Drop all the rest using tc filters
on the egress of 'br0' and 'h1'.
In the software data path, the problem can be solved by matching on the
inner destination MAC or dropping unwanted packets at the egress of the
VXLAN device, but this is not currently supported by mlxsw.
Fixes: 94d302deae25 ("selftests: mlxsw: Add a test for VxLAN flooding")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When a rawmidi output stream is closed, it calls the drain at first,
then does trigger-off only when the drain returns -ERESTARTSYS as a
fallback. It implies that each driver should turn off the stream
properly after the drain. Meanwhile, USB-audio MIDI interface didn't
change the port->active flag after the drain. This may leave the
output work picking up the port that is closed right now, which
eventually leads to a use-after-free for the already released rawmidi
object.
This patch fixes the bug by properly clearing the port->active flag
after the output drain.
Reported-by: syzbot+70e777a39907d6d5fd0a@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/00000000000011555605dceaff03@google.com
Link: https://lore.kernel.org/r/20220420130247.22062-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Matthew Wilcox (Oracle)
Nicholas Piggin
Muchun Song
Alistair Popple
Aleksandr Nogikh
Vincenzo Frascino
Nico Pache
Sidhartha Kumar
Christophe Leroy
Nadav Amit
Shakeel Butt
Xu Yu
Naoya Horiguchi
Zheyu Ma
Randy Dunlap
Anup Patel
Paolo Bonzini
Mingwei Zhang
Tim Crawford
Gongjun Song
Sean Christopherson
Thomas Huth
Like Xu
Wanpeng Li
Tom Rix
Christian Brauner
Duoming Zhou
Andy Chi
Ronnie Sahlberg
Paulo Alcantara
Linus Torvalds
Mikulas Patocka
Ido Schimmel
Takashi Iwai