The usage of gnttab_end_foreign_access() in xenhcd_gnttab_done() is
not safe against a malicious backend, as the backend could keep the
I/O page mapped and modify it even after the granted memory page is
being used for completely other purposes in the local system.
So replace that use case with gnttab_try_end_foreign_access() and
disable the PV host adapter in case the backend didn't stop using the
granted page.
In xenhcd_urb_request_done() immediately return in case of setting
the device state to "error" instead of looking into further backend
responses.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
V2:
- use gnttab_try_end_foreign_access()
Remove gnttab_query_foreign_access(), as it is unused and unsafe to
use.
All previous use cases assumed a grant would not be in use after
gnttab_query_foreign_access() returned 0. This information is useless
in best case, as it only refers to a situation in the past, which could
have changed already.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Using gnttab_query_foreign_access() is unsafe, as it is racy by design.
The use case in the gntalloc driver is not needed at all. While at it
replace the call of gnttab_end_foreign_access_ref() with a call of
gnttab_end_foreign_access(), which is what is really wanted there. In
case the grant wasn't used due to an allocation failure, just free the
grant via gnttab_free_grant_reference().
This is CVE-2022-23039 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
V3:
- fix __del_gref() (Jan Beulich)
It isn't enough to check whether a grant is still being in use by
calling gnttab_query_foreign_access(), as a mapping could be realized
by the other side just after having called that function.
In case the call was done in preparation of revoking a grant it is
better to do so via gnttab_try_end_foreign_access() and check the
success of that operation instead.
This is CVE-2022-23038 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
V2:
- use gnttab_try_end_foreign_access()
It isn't enough to check whether a grant is still being in use by
calling gnttab_query_foreign_access(), as a mapping could be realized
by the other side just after having called that function.
In case the call was done in preparation of revoking a grant it is
better to do so via gnttab_end_foreign_access_ref() and check the
success of that operation instead.
This is CVE-2022-23037 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
V2:
- use gnttab_try_end_foreign_access()
V3:
- don't use gnttab_try_end_foreign_access()
It isn't enough to check whether a grant is still being in use by
calling gnttab_query_foreign_access(), as a mapping could be realized
by the other side just after having called that function.
In case the call was done in preparation of revoking a grant it is
better to do so via gnttab_end_foreign_access_ref() and check the
success of that operation instead.
For the ring allocation use alloc_pages_exact() in order to avoid
high order pages in case of a multi-page ring.
If a grant wasn't unmapped by the backend without persistent grants
being used, set the device state to "error".
This is CVE-2022-23036 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
---
V2:
- use gnttab_try_end_foreign_access()
V4:
- use alloc_pages_exact() and free_pages_exact()
- set state to error if backend didn't unmap (Roger Pau Monné)
Add a new grant table function gnttab_try_end_foreign_access(), which
will remove and free a grant if it is not in use.
Its main use case is to either free a grant if it is no longer in use,
or to take some other action if it is still in use. This other action
can be an error exit, or (e.g. in the case of blkfront persistent grant
feature) some special handling.
This is CVE-2022-23036, CVE-2022-23038 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
V2:
- new patch
V4:
- add comments to header (Jan Beulich)
Letting xenbus_grant_ring() tear down grants in the error case is
problematic, as the other side could already have used these grants.
Calling gnttab_end_foreign_access_ref() without checking success is
resulting in an unclear situation for any caller of xenbus_grant_ring()
as in the error case the memory pages of the ring page might be
partially mapped. Freeing them would risk unwanted foreign access to
them, while not freeing them would leak memory.
In order to remove the need to undo any gnttab_grant_foreign_access()
calls, use gnttab_alloc_grant_references() to make sure no further
error can occur in the loop granting access to the ring pages.
It should be noted that this way of handling removes leaking of
grant entries in the error case, too.
This is CVE-2022-23040 / part of XSA-396.
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Pull btrfs fixes from David Sterba:
"A few more fixes for various problems that have user visible effects
or seem to be urgent:
- fix corruption when combining DIO and non-blocking io_uring over
multiple extents (seen on MariaDB)
- fix relocation crash due to premature return from commit
- fix quota deadlock between rescan and qgroup removal
- fix item data bounds checks in tree-checker (found on a fuzzed
image)
- fix fsync of prealloc extents after EOF
- add missing run of delayed items after unlink during log replay
- don't start relocation until snapshot drop is finished
- fix reversed condition for subpage writers locking
- fix warning on page error"
* tag 'for-5.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fallback to blocking mode when doing async dio over multiple extents
btrfs: add missing run of delayed items after unlink during log replay
btrfs: qgroup: fix deadlock between rescan worker and remove qgroup
btrfs: fix relocation crash due to premature return from btrfs_commit_transaction()
btrfs: do not start relocation until in progress drops are done
btrfs: tree-checker: use u64 for item data end to avoid overflow
btrfs: do not WARN_ON() if we have PageError set
btrfs: fix lost prealloc extents beyond eof after full fsync
btrfs: subpage: fix a wrong check on subpage->writers
Pull kvm fixes from Paolo Bonzini:
"x86 guest:
- Tweaks to the paravirtualization code, to avoid using them when
they're pointless or harmful
x86 host:
- Fix for SRCU lockdep splat
- Brown paper bag fix for the propagation of errno"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: pull kvm->srcu read-side to kvm_arch_vcpu_ioctl_run
KVM: x86/mmu: Passing up the error state of mmu_alloc_shadow_roots()
KVM: x86: Yield to IPI target vCPU only if it is busy
x86/kvmclock: Fix Hyper-V Isolated VM's boot issue when vCPUs > 64
x86/kvm: Don't waste memory if kvmclock is disabled
x86/kvm: Don't use PV TLB/yield when mwait is advertised
Pull powerpc fix from Michael Ellerman:
"Fix build failure when CONFIG_PPC_64S_HASH_MMU is not set.
Thanks to Murilo Opsfelder Araujo, and Erhard F"
* tag 'powerpc-5.17-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64s: Fix build failure when CONFIG_PPC_64S_HASH_MMU is not set
Pull tracing fixes from Steven Rostedt:
- Fix sorting on old "cpu" value in histograms
- Fix return value of __setup() boot parameter handlers
* tag 'trace-v5.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix return value of __setup handlers
tracing/histogram: Fix sorting on old "cpu" value
Pull input updates from Dmitry Torokhov:
- a fixup for Goodix touchscreen driver allowing it to work on certain
Cherry Trail devices
- a fix for imbalanced enable/disable regulator in Elam touchpad driver
that became apparent when used with Asus TF103C 2-in-1 dock
- a couple new input keycodes used on newer keyboards
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
HID: add mapping for KEY_ALL_APPLICATIONS
HID: add mapping for KEY_DICTATE
Input: elan_i2c - fix regulator enable count imbalance after suspend/resume
Input: elan_i2c - move regulator_[en|dis]able() out of elan_[en|dis]able_power()
Input: goodix - workaround Cherry Trail devices with a bogus ACPI Interrupt() resource
Input: goodix - use the new soc_intel_is_byt() helper
Input: samsung-keypad - properly state IOMEM dependency
Merge misc fixes from Andrew Morton:
"8 patches.
Subsystems affected by this patch series: mm (hugetlb, pagemap, and
userfaultfd), memfd, selftests, and kconfig"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
configs/debug: set CONFIG_DEBUG_INFO=y properly
proc: fix documentation and description of pagemap
kselftest/vm: fix tests build with old libc
memfd: fix F_SEAL_WRITE after shmem huge page allocated
mm: fix use-after-free when anon vma name is used after vma is freed
mm: prevent vm_area_struct::anon_name refcount saturation
mm: refactor vm_area_struct::anon_vma_name usage code
selftests/vm: cleanup hugetlb file after mremap test
Pull s390 fixes from Vasily Gorbik:
- Fix HAVE_DYNAMIC_FTRACE_WITH_ARGS implementation by providing correct
switching between ftrace_caller/ftrace_regs_caller and supplying
pt_regs only when ftrace_regs_caller is activated.
- Fix exception table sorting.
- Fix breakage of kdump tooling by preserving metadata it cannot
function without.
* tag 's390-5.17-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/extable: fix exception table sorting
s390/ftrace: fix arch_ftrace_get_regs implementation
s390/ftrace: fix ftrace_caller/ftrace_regs_caller generation
s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE
The error message when I build vm tests on debian10 (GLIBC 2.28):
userfaultfd.c: In function `userfaultfd_pagemap_test':
userfaultfd.c:1393:37: error: `MADV_PAGEOUT' undeclared (first use
in this function); did you mean `MADV_RANDOM'?
if (madvise(area_dst, test_pgsize, MADV_PAGEOUT))
^~~~~~~~~~~~
MADV_RANDOM
This patch includes these newer definitions from UAPI linux/mman.h, is
useful to fix tests build on systems without these definitions in glibc
sys/mman.h.
Link: https://lkml.kernel.org/r/20220227055330.43087-2-zhouchengming@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.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>
Wangyong reports: after enabling tmpfs filesystem to support transparent
hugepage with the following command:
echo always > /sys/kernel/mm/transparent_hugepage/shmem_enabled
the docker program tries to add F_SEAL_WRITE through the following
command, but it fails unexpectedly with errno EBUSY:
fcntl(5, F_ADD_SEALS, F_SEAL_WRITE) = -1.
That is because memfd_tag_pins() and memfd_wait_for_pins() were never
updated for shmem huge pages: checking page_mapcount() against
page_count() is hopeless on THP subpages - they need to check
total_mapcount() against page_count() on THP heads only.
Make memfd_tag_pins() (compared > 1) as strict as memfd_wait_for_pins()
(compared != 1): either can be justified, but given the non-atomic
total_mapcount() calculation, it is better now to be strict. Bear in
mind that total_mapcount() itself scans all of the THP subpages, when
choosing to take an XA_CHECK_SCHED latency break.
Also fix the unlikely xa_is_value() case in memfd_wait_for_pins(): if a
page has been swapped out since memfd_tag_pins(), then its refcount must
have fallen, and so it can safely be untagged.
Link: https://lkml.kernel.org/r/a4f79248-df75-2c8c-3df-ba3317ccb5da@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Reported-by: wangyong <wang.yong12@zte.com.cn>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: CGEL ZTE <cgel.zte@gmail.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A deep process chain with many vmas could grow really high. With
default sysctl_max_map_count (64k) and default pid_max (32k) the max
number of vmas in the system is 2147450880 and the refcounter has
headroom of 1073774592 before it reaches REFCOUNT_SATURATED
(3221225472).
Therefore it's unlikely that an anonymous name refcounter will overflow
with these defaults. Currently the max for pid_max is PID_MAX_LIMIT
(4194304) and for sysctl_max_map_count it's INT_MAX (2147483647). In
this configuration anon_vma_name refcount overflow becomes theoretically
possible (that still require heavy sharing of that anon_vma_name between
processes).
kref refcounting interface used in anon_vma_name structure will detect a
counter overflow when it reaches REFCOUNT_SATURATED value but will only
generate a warning and freeze the ref counter. This would lead to the
refcounted object never being freed. A determined attacker could leak
memory like that but it would be rather expensive and inefficient way to
do so.
To ensure anon_vma_name refcount does not overflow, stop anon_vma_name
sharing when the refcount reaches REFCOUNT_MAX (2147483647), which still
leaves INT_MAX/2 (1073741823) values before the counter reaches
REFCOUNT_SATURATED. This should provide enough headroom for raising the
refcounts temporarily.
Link: https://lkml.kernel.org/r/20220223153613.835563-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Chris Hyser <chris.hyser@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Colin Cross <ccross@google.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xiaofeng Cao <caoxiaofeng@yulong.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following build failure occurs when CONFIG_PPC_64S_HASH_MMU is not
set:
arch/powerpc/kernel/setup_64.c: In function ‘setup_per_cpu_areas’:
arch/powerpc/kernel/setup_64.c:811:21: error: ‘mmu_linear_psize’ undeclared (first use in this function); did you mean ‘mmu_virtual_psize’?
811 | if (mmu_linear_psize == MMU_PAGE_4K)
| ^~~~~~~~~~~~~~~~
| mmu_virtual_psize
arch/powerpc/kernel/setup_64.c:811:21: note: each undeclared identifier is reported only once for each function it appears in
Move the declaration of mmu_linear_psize outside of
CONFIG_PPC_64S_HASH_MMU ifdef.
After the above is fixed, it fails later with the following error:
ld: arch/powerpc/kexec/file_load_64.o: in function `.arch_kexec_kernel_image_probe':
file_load_64.c:(.text+0x1c1c): undefined reference to `.add_htab_mem_range'
Fix that, too, by conditioning add_htab_mem_range() symbol to
CONFIG_PPC_64S_HASH_MMU.
Fixes: 387e220a2e ("powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU")
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215567
Link: https://lore.kernel.org/r/20220301204743.45133-1-muriloo@linux.ibm.com
