When built at -Os, gcc-12 recognizes an strlen() pattern in nolibc_strlen()
and replaces it with a jump to strlen(), which is not defined as a symbol
and breaks compilation. Worse, when the function is called strlen(), the
function is simply replaced with a jump to itself, hence becomes an
infinite loop.
One way to avoid this is to always set -ffreestanding, but the calling
code doesn't know this and there's no way (either via attributes or
pragmas) to globally enable it from include files, effectively leaving
a painful situation for the caller.
Alexey suggested to place an empty asm() statement inside the loop to
stop gcc from recognizing a well-known pattern, which happens to work
pretty fine. At least it allows us to make sure our local definition
is not replaced with a self jump.
The function only needs to be renamed back to strlen() so that the symbol
exists, which implies that nolibc_strlen() which is used on variable
strings has to be declared as a macro that points back to it before the
strlen() macro is redifined.
It was verified to produce valid code with gcc 3.4 to 12.1 at different
optimization levels, and both with constant and variable strings.
In case this problem surfaces again in the future, an alternate approach
consisting in adding an optimize("no-tree-loop-distribute-patterns")
function attribute for gcc>=12 worked as well but is less pretty.
Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/r/202210081618.754a77db-yujie.liu@intel.com
Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc")
Fixes: 96980b833a ("tools/nolibc/string: do not use __builtin_strlen() at -O0")
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
lru_gen_add_mm() has been added within an IRQ-off region in the commit
mentioned below. The other invocations of lru_gen_add_mm() are not within
an IRQ-off region.
The invocation within IRQ-off region is problematic on PREEMPT_RT because
the function is using a spin_lock_t which must not be used within
IRQ-disabled regions.
The other invocations of lru_gen_add_mm() occur while
task_struct::alloc_lock is acquired. Move lru_gen_add_mm() after
interrupts are enabled and before task_unlock().
Link: https://lkml.kernel.org/r/20221026134830.711887-1-bigeasy@linutronix.de
Fixes: bd74fdaea1 ("mm: multi-gen LRU: support page table walks")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Yu Zhao <yuzhao@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Before the do-while loop in mtree_range_walk(), the variables next, min,
max need to be initialized. The variables last, prev_min and prev_max are
set within the loop body before they are eventually used after exiting the
loop body.
As it is a do-while loop, the loop body is executed at least once, so the
variables last, prev_min and prev_max do not need to be initialized before
the loop body.
Remove unneeded initialization of last and prev_min.
The needless initialization was reported by clang-analyzer as Dead Stores.
As the compiler already identifies these assignments as unneeded, it
optimizes the assignments away. Hence:
No functional change. No change in object code.
Link: https://lkml.kernel.org/r/20221026120029.12555-2-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The kernel test robot flagged a recursive lock as a result of a conversion
from kmap_atomic() to kmap_local_folio()[Link]
The cause was due to the code depending on the kmap_atomic() side effect
of disabling page faults. In that case the code expects the fault to fail
and take the fallback case.
git archaeology implied that the recursion may not be an actual bug.[1]
However, depending on the implementation of the mmap_lock and the
condition of the call there may still be a deadlock.[2] So this is not
purely a lockdep issue. Considering a single threaded call stack there
are 3 options.
1) Different mm's are in play (no issue)
2) Readlock implementation is recursive and same mm is in play
(no issue)
3) Readlock implementation is _not_ recursive (issue)
The mmap_lock is recursive so with a single thread there is no issue.
However, Matthew pointed out a deadlock scenario when you consider
additional process' and threads thusly.
"The readlock implementation is only recursive if nobody else has taken a
write lock. If you have a multithreaded process, one of the other threads
can call mmap() and that will prevent recursion (due to fairness). Even
if it's a different process that you're trying to acquire the mmap read
lock on, you can still get into a deadly embrace. eg:
process A thread 1 takes read lock on own mmap_lock
process A thread 2 calls mmap, blocks taking write lock
process B thread 1 takes page fault, read lock on own mmap lock
process B thread 2 calls mmap, blocks taking write lock
process A thread 1 blocks taking read lock on process B
process B thread 1 blocks taking read lock on process A
Now all four threads are blocked waiting for each other."
Regardless using pagefault_disable() ensures that no matter what locking
implementation is used a deadlock will not occur. Add an explicit
pagefault_disable() and a big comment to explain this for future souls
looking at this code.
[1] https://lore.kernel.org/all/Y1MymJ%2FINb45AdaY@iweiny-desk3/
[2] https://lore.kernel.org/lkml/Y1bXBtGTCym77%2FoD@casper.infradead.org/
Link: https://lkml.kernel.org/r/20221025220108.2366043-1-ira.weiny@intel.com
Link: https://lore.kernel.org/r/202210211215.9dc6efb5-yujie.liu@intel.com
Fixes: 7a7256d5f5 ("shmem: convert shmem_mfill_atomic_pte() to use a folio")
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: kernel test robot <yujie.liu@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kmap() and kmap_atomic() are being deprecated in favor of
kmap_local_page() which is appropriate for any thread local context.[1]
A recent locking bug report with userfaultfd showed that the conversion of
the kmap_atomic()'s in those code flows requires care with regard to the
prevention of deadlock.[2]
git archaeology implied that the recursion may not be an actual bug.[3]
However, depending on the implementation of the mmap_lock and the
condition of the call there may still be a deadlock.[4] So this is not
purely a lockdep issue. Considering a single threaded call stack there
are 3 options.
1) Different mm's are in play (no issue)
2) Readlock implementation is recursive and same mm is in play
(no issue)
3) Readlock implementation is _not_ recursive (issue)
The mmap_lock is recursive so with a single thread there is no issue.
However, Matthew pointed out a deadlock scenario when you consider
additional process' and threads thusly.
"The readlock implementation is only recursive if nobody else has taken a
write lock. If you have a multithreaded process, one of the other threads
can call mmap() and that will prevent recursion (due to fairness). Even
if it's a different process that you're trying to acquire the mmap read
lock on, you can still get into a deadly embrace. eg:
process A thread 1 takes read lock on own mmap_lock
process A thread 2 calls mmap, blocks taking write lock
process B thread 1 takes page fault, read lock on own mmap lock
process B thread 2 calls mmap, blocks taking write lock
process A thread 1 blocks taking read lock on process B
process B thread 1 blocks taking read lock on process A
Now all four threads are blocked waiting for each other."
Regardless using pagefault_disable() ensures that no matter what locking
implementation is used a deadlock will not occur.
Complete kmap conversion in userfaultfd by replacing the kmap() and
kmap_atomic() calls with kmap_local_page(). When replacing the
kmap_atomic() call ensure page faults continue to be disabled to support
the correct fall back behavior and add a comment to inform future souls of
the requirement.
[1] https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/
[2] https://lore.kernel.org/all/Y1Mh2S7fUGQ%2FiKFR@iweiny-desk3/
[3] https://lore.kernel.org/all/Y1MymJ%2FINb45AdaY@iweiny-desk3/
[4] https://lore.kernel.org/lkml/Y1bXBtGTCym77%2FoD@casper.infradead.org/
[ira.weiny@intel.com: v2]
Link: https://lkml.kernel.org/r/20221025220136.2366143-1-ira.weiny@intel.com
Link: https://lkml.kernel.org/r/20221024043452.1491677-1-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
User access macros must ensure their arguments are evaluated only once if
they are used more than once in the macro body. Adding
instrument_put_user() to __put_user_size() resulted in double evaluation
of the `ptr` argument, which led to correctness issues when performing
e.g. unsafe_put_user(..., p++, ...).
To fix those issues, evaluate the `ptr` argument of __put_user_size() at
the beginning of the macro.
Link: https://lkml.kernel.org/r/20221024212144.2852069-4-glider@google.com
Fixes: 888f84a6da ("x86: asm: instrument usercopy in get_user() and put_user()")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: youling257 <youling257@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Although page allocation always clears page->private in the first page or
head page of an allocation, it has never made a point of clearing
page->private in the tails (though 0 is often what is already there).
But now commit 71e2d666ef ("mm/huge_memory: do not clobber swp_entry_t
during THP split") issues a warning when page_tail->private is found to be
non-0 (unless it's swapcache).
Change that warning to dump page_tail (which also dumps head), instead of
just the head: so far we have seen dead000000000122, dead000000000003,
dead000000000001 or 0000000000000002 in the raw output for tail private.
We could just delete the warning, but today's consensus appears to want
page->private to be 0, unless there's a good reason for it to be set: so
now clear it in prep_compound_tail() (more general than just for THP; but
not for high order allocation, which makes no pass down the tails).
Link: https://lkml.kernel.org/r/1c4233bb-4e4d-5969-fbd4-96604268a285@google.com
Fixes: 71e2d666ef ("mm/huge_memory: do not clobber swp_entry_t during THP split")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
A common use case for hugetlbfs is for the application to create
memory pools backed by huge pages, which then get handed over to
some malloc library (eg. jemalloc) for further management.
That malloc library may be doing MADV_DONTNEED calls on memory
that is no longer needed, expecting those calls to happen on
PAGE_SIZE boundaries.
However, currently the MADV_DONTNEED code rounds up any such
requests to HPAGE_PMD_SIZE boundaries. This leads to undesired
outcomes when jemalloc expects a 4kB MADV_DONTNEED, but 2MB of
memory get zeroed out, instead.
Use of pre-built shared libraries means that user code does not
always know the page size of every memory arena in use.
Avoid unexpected data loss with MADV_DONTNEED by rounding up
only to PAGE_SIZE (in do_madvise), and rounding down to huge
page granularity.
That way programs will only get as much memory zeroed out as
they requested.
Link: https://lkml.kernel.org/r/20221021192805.366ad573@imladris.surriel.com
Fixes: 90e7e7f5ef ("mm: enable MADV_DONTNEED for hugetlb mappings")
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
fs/ext4/super.c:1744:19: warning: 'deprecated_msg' defined but not used [-Wunused-const-variable=]
Reported-by: kernel test robot <lkp@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull RTC fixes from Alexandre Belloni:
"Fix wakeup support that broke on multiple platforms"
* tag 'rtc-6.1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
rtc: cmos: fix build on non-ACPI platforms
rtc: cmos: Fix wake alarm breakage
Pull MMC fixes from Ulf Hansson:
"MMC core:
- Cancel recovery work on cleanup to avoid NULL pointer dereference
- Fix error path in the read/write error recovery path
- Fix kernel panic when remove non-standard SDIO card
- Fix WRITE_ZEROES handling for CQE
MMC host:
- sdhci_am654: Fixup Kconfig dependency for REGMAP_MMIO
- sdhci-esdhc-imx: Avoid warning of misconfigured bus-width
- sdhci-pci: Disable broken HS400 ES mode for ASUS BIOS on Jasper
Lake"
* tag 'mmc-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
mmc: sdhci_am654: 'select', not 'depends' REGMAP_MMIO
mmc: core: Fix WRITE_ZEROES CQE handling
mmc: core: Fix kernel panic when remove non-standard SDIO card
mmc: sdhci-pci-core: Disable ES for ASUS BIOS on Jasper Lake
mmc: sdhci-esdhc-imx: Propagate ESDHC_FLAG_HS400* only on 8bit bus
mmc: queue: Cancel recovery work on cleanup
mmc: block: Remove error check of hw_reset on reset
Pull sound fixes from Takashi Iwai:
"A collection of small fixes:
- fixes for regressions by the recent ALSA control hash usages
- fixes for UAF with del_timer() at removals in a few drivers
- char signedness fixes
- a few memory leak fixes in error paths
- device-specific fixes / quirks for Intel SOF, AMD, HD-audio,
USB-audio, and various ASoC codecs"
* tag 'sound-6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (50 commits)
ALSA: aoa: Fix I2S device accounting
ALSA: Use del_timer_sync() before freeing timer
ALSA: aoa: i2sbus: fix possible memory leak in i2sbus_add_dev()
ALSA: rme9652: use explicitly signed char
ALSA: au88x0: use explicitly signed char
ALSA: hda/realtek: Add another HP ZBook G9 model quirks
ALSA: usb-audio: Add quirks for M-Audio Fast Track C400/600
ASoC: SOF: Intel: hda-codec: fix possible memory leak in hda_codec_device_init()
ASoC: amd: yc: Add Lenovo Thinkbook 14+ 2022 21D0 to quirks table
ASoC: Intel: Skylake: fix possible memory leak in skl_codec_device_init()
ALSA: ac97: Use snd_ctl_rename() to rename a control
ALSA: ca0106: Use snd_ctl_rename() to rename a control
ALSA: emu10k1: Use snd_ctl_rename() to rename a control
ALSA: hda/realtek: Use snd_ctl_rename() to rename a control
ALSA: usb-audio: Use snd_ctl_rename() to rename a control
ALSA: control: add snd_ctl_rename()
ALSA: ac97: fix possible memory leak in snd_ac97_dev_register()
ASoC: SOF: Intel: pci-tgl: fix ADL-N descriptor
ASoC: qcom: lpass-cpu: Mark HDMI TX parity register as volatile
ASoC: amd: yc: Adding Lenovo ThinkBook 14 Gen 4+ ARA and Lenovo ThinkBook 16 Gen 4+ ARA to the Quirks List
...
Pull drm fixes from Dave Airlie:
"Regularly scheduled fixes for drm, live from a Red Hat office for the
first time in a while.
The core has two fixes, one for scheduler leak and one for aperture
uninit read.
Otherwise a single bridge fix, and msm, amdgpu/kfd and i915 have a set
of fixes each.
sched:
- Stop leaking fences when killing a sched entity.
aperture:
- Avoid uninitialized read in aperture_remove_conflicting_pci_device()
bridge:
- Fix HPD on bridge/ps8640.
msm:
- Fix shrinker deadlock
- Fix crash during suspend after unbind
- Fix IRQ lifetime issues
- Fix potential memory corruption with too many bridges
- Fix memory corruption on GPU state capture
amdgpu:
- Stable pstate fix
- SMU 13.x updates
- SR-IOV fixes
- PCI AER fix
- GC 11.x fixes
- Display fixes
- Expose IMU firmware version for debugging
- Plane modifier fix
- S0i3 fix
amdkfd:
- Fix possible memory leak
- Fix GC 10.x cache info reporting
i915:
- Extend Wa_1607297627 to Alderlake-P
- Keep PCI autosuspend control 'on' by default on all dGPU
- Reset frl trained flag before restarting FRL training"
* tag 'drm-fixes-2022-10-28' of git://anongit.freedesktop.org/drm/drm: (39 commits)
fbdev/core: Avoid uninitialized read in aperture_remove_conflicting_pci_device()
drm/amdgpu: disallow gfxoff until GC IP blocks complete s2idle resume
drm/scheduler: fix fence ref counting
drm/amd/display: Revert logic for plane modifiers
drm/amdkfd: correct the cache info for gfx1036
drm/amdkfd: update gfx1037 Lx cache setting
drm/amdgpu: skip mes self test for gc 11.0.3 in recover
drm/amd: Add IMU fw version to fw version queries
drm/amd/display: Don't return false if no stream
drm/amd/display: Remove wrong pipe control lock
drm/amd/pm: allow gfxoff on gc_11_0_3
drm/amdkfd: Fix memory leak in kfd_mem_dmamap_userptr()
drm/amdgpu: Remove ATC L2 access for MMHUB 2.1.x
drm/i915/dp: Reset frl trained flag before restarting FRL training
drm/i915/dgfx: Keep PCI autosuspend control 'on' by default on all dGPU
drm/i915: Extend Wa_1607297627 to Alderlake-P
drm/amdgpu: Adjust MES polling timeout for sriov
drm/amd/pm: update driver-if header for smu_v13_0_10
drm/amdgpu: fix pstate setting issue
drm/bridge: ps8640: Add back the 50 ms mystery delay after HPD
...
Pull crypto fix from Herbert Xu:
"Fix an alignment crash in x86/polyval"
* tag 'v6.1-p3' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: x86/polyval - Fix crashes when keys are not 16-byte aligned
KASAN reported a null-ptr-deref error:
KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f]
CPU: 1 PID: 379
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:destroy_workqueue+0x2f/0x740
RSP: 0018:ffff888016137df8 EFLAGS: 00000202
...
Call Trace:
ib_core_cleanup+0xa/0xa1 [ib_core]
__do_sys_delete_module.constprop.0+0x34f/0x5b0
do_syscall_64+0x3a/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa1a0d221b7
...
It is because the fail of roce_gid_mgmt_init() is ignored:
ib_core_init()
roce_gid_mgmt_init()
gid_cache_wq = alloc_ordered_workqueue # fail
...
ib_core_cleanup()
roce_gid_mgmt_cleanup()
destroy_workqueue(gid_cache_wq)
# destroy an unallocated wq
Fix this by catching the fail of roce_gid_mgmt_init() in ib_core_init().
Fixes: 03db3a2d81 ("IB/core: Add RoCE GID table management")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Link: https://lore.kernel.org/r/20221025024146.109137-1-chenzhongjin@huawei.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
After some off-list discussion with Marek Vasut and Geert Uytterhoeven
and finally a kx022a driver related discussion with Joe Perches
https://lore.kernel.org/lkml/92c3f72e60bc99bf4a21da259b4d78c1bdca447d.camel@perches.com/
it seems that my status as a reviewer has been wrong. I do look after
the ROHM/Kionix drivers I've authored and currently I am also paid to do
so as is reflected by the 'S: Supported'. According to Joe, the reviewer
entry in MAINTAINERS do not indicate such level of support and having a
reviewer supporting an IC is a contradiction.
Switch undersigned from a reviewer to a maintainer for IC drivers I am
taking care of.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Merge an IRQ override quirk, an ACPI PCC code fix and a device
properties documentation update for 6.1-rc3:
- Make the ACPI device resources code skip IRQ override on Asus
Vivobook S5602ZA (Tamim Khan).
- Fix a possible integer overflow during multiplication in the ACPI
PCC code (Manank Patel).
- Fix the documentation of the *_match_string() family of functions to
properly cover the return value (Andy Shevchenko).
* acpi-resource:
ACPI: resource: Skip IRQ override on Asus Vivobook S5602ZA
* acpi-pcc:
ACPI: PCC: Fix unintentional integer overflow
* devprop:
device property: Fix documentation for *_match_string() APIs
Merge a hiberantion-related fix, a generic power domains code fix and
a pm-graph update for 6.1-rc1:
- Allow hybrid sleep to use suspend-to-idle as a system suspend method
if it is the current suspend method of choice (Mario Limonciello).
- Fix handling of unavailable/disabled idle states in the generic
power domains code (Sudeep Holla).
- Update the pm-graph suite of utilities to version 5.10 which is
fixes-mostly and does not add any new features (Todd Brandt).
* pm-sleep:
PM: hibernate: Allow hybrid sleep to work with s2idle
* pm-domains:
PM: domains: Fix handling of unavailable/disabled idle states
* pm-tools:
pm-graph v5.10
In cap_inode_getsecurity(), we will use vfs_getxattr_alloc() to
complete the memory allocation of tmpbuf, if we have completed
the memory allocation of tmpbuf, but failed to call handler->get(...),
there will be a memleak in below logic:
|-- ret = (int)vfs_getxattr_alloc(mnt_userns, ...)
| /* ^^^ alloc for tmpbuf */
|-- value = krealloc(*xattr_value, error + 1, flags)
| /* ^^^ alloc memory */
|-- error = handler->get(handler, ...)
| /* error! */
|-- *xattr_value = value
| /* xattr_value is &tmpbuf (memory leak!) */
So we will try to free(tmpbuf) after vfs_getxattr_alloc() fails to fix it.
Cc: stable@vger.kernel.org
Fixes: 8db6c34f1d ("Introduce v3 namespaced file capabilities")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
[PM: subject line and backtrace tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Instead of generic description, mention what reset_lock actually
protects i.e. lock to serialize xmit and tx_timeout execution.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On 64 bit host, if the guest doesn't have X86_FEATURE_LM, KVM will
access 16 gprs to 32-bit smram image, causing out-ouf-bound ram
access.
On 32 bit host, the rsm_load_state_64/enter_smm_save_state_64
is compiled out, thus access overflow can't happen.
Fixes: b443183a25 ("KVM: x86: Reduce the number of emulator GPRs to '8' for 32-bit KVM")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221025124741.228045-15-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Update the emulation mode when handling writes to CR0, because
toggling CR0.PE switches between Real and Protected Mode, and toggling
CR0.PG when EFER.LME=1 switches between Long and Protected Mode.
This is likely a benign bug because there is no writeback of state,
other than the RIP increment, and when toggling CR0.PE, the CPU has
to execute code from a very low memory address.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221025124741.228045-14-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Update the emulation mode after RSM so that RIP will be correctly
written back, because the RSM instruction can switch the CPU mode from
32 bit (or less) to 64 bit.
This fixes a guest crash in case the #SMI is received while the guest
runs a code from an address > 32 bit.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221025124741.228045-13-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some instructions update the cpu execution mode, which needs to update the
emulation mode.
Extract this code, and make assign_eip_far use it.
assign_eip_far now reads CS, instead of getting it via a parameter,
which is ok, because callers always assign CS to the same value
before calling this function.
No functional change is intended.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221025124741.228045-12-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SYSEXIT is one of the instructions that can change the
processor mode, thus ctxt->mode should be updated after it.
Note that this is likely a benign bug, because the only problematic
mode change is from 32 bit to 64 bit which can lead to truncation of RIP,
and it is not possible to do with sysexit,
since sysexit running in 32 bit mode will be limited to 32 bit version.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221025124741.228045-11-mlevitsk@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tag "guest_saw_irq" as "volatile" to ensure that the compiler will never
optimize away lookups. Relying on the compiler thinking that the flag
is global and thus might change also works, but it's subtle, less robust,
and looks like a bug at first glance, e.g. risks being "fixed" and
breaking the test.
Make the flag "static" as well since convincing the compiler it's global
is no longer necessary.
Alternatively, the flag could be accessed with {READ,WRITE}_ONCE(), but
literally every access would need the wrappers, and eking out performance
isn't exactly top priority for selftests.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221013211234.1318131-17-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tests for races between shinfo_cache (de)activation and hypercall+ioctl()
processing. KVM has had bugs where activating the shared info cache
multiple times and/or with concurrent users results in lock corruption,
NULL pointer dereferences, and other fun.
For the timer injection testcase (#22), re-arm the timer until the IRQ
is successfully injected. If the timer expires while the shared info
is deactivated (invalid), KVM will drop the event.
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221013211234.1318131-16-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kmemleak reported memory leaks in dsa_loop_init():
kmemleak: 12 new suspected memory leaks
unreferenced object 0xffff8880138ce000 (size 2048):
comm "modprobe", pid 390, jiffies 4295040478 (age 238.976s)
backtrace:
[<000000006a94f1d5>] kmalloc_trace+0x26/0x60
[<00000000a9c44622>] phy_device_create+0x5d/0x970
[<00000000d0ee2afc>] get_phy_device+0xf3/0x2b0
[<00000000dca0c71f>] __fixed_phy_register.part.0+0x92/0x4e0
[<000000008a834798>] fixed_phy_register+0x84/0xb0
[<0000000055223fcb>] dsa_loop_init+0xa9/0x116 [dsa_loop]
...
There are two reasons for memleak in dsa_loop_init().
First, fixed_phy_register() create and register phy_device:
fixed_phy_register()
get_phy_device()
phy_device_create() # freed by phy_device_free()
phy_device_register() # freed by phy_device_remove()
But fixed_phy_unregister() only calls phy_device_remove().
So the memory allocated in phy_device_create() is leaked.
Second, when mdio_driver_register() fail in dsa_loop_init(),
it just returns and there is no cleanup for phydevs.
Fix the problems by catching the error of mdio_driver_register()
in dsa_loop_init(), then calling both fixed_phy_unregister() and
phy_device_free() to release phydevs.
Also add a function for phydevs cleanup to avoid duplacate.
Fixes: 98cd1552ea ("net: dsa: Mock-up driver")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
`hostname` needs to be set as null-pointer after free in
`cifs_put_tcp_session` function, or when `cifsd` thread attempts
to resolve hostname and reconnect the host, the thread would deref
the invalid pointer.
Here is one of practical backtrace examples as reference:
Task 477
---------------------------
do_mount
path_mount
do_new_mount
vfs_get_tree
smb3_get_tree
smb3_get_tree_common
cifs_smb3_do_mount
cifs_mount
mount_put_conns
cifs_put_tcp_session
--> kfree(server->hostname)
cifsd
---------------------------
kthread
cifs_demultiplex_thread
cifs_reconnect
reconn_set_ipaddr_from_hostname
--> if (!server->hostname)
--> if (server->hostname[0] == '\0') // !! UAF fault here
CIFS: VFS: cifs_mount failed w/return code = -112
mount error(112): Host is down
BUG: KASAN: use-after-free in reconn_set_ipaddr_from_hostname+0x2ba/0x310
Read of size 1 at addr ffff888108f35380 by task cifsd/480
CPU: 2 PID: 480 Comm: cifsd Not tainted 6.1.0-rc2-00106-gf705792f89dd-dirty #25
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x68/0x85
print_report+0x16c/0x4a3
kasan_report+0x95/0x190
reconn_set_ipaddr_from_hostname+0x2ba/0x310
__cifs_reconnect.part.0+0x241/0x800
cifs_reconnect+0x65f/0xb60
cifs_demultiplex_thread+0x1570/0x2570
kthread+0x2c5/0x380
ret_from_fork+0x22/0x30
</TASK>
Allocated by task 477:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_kmalloc+0x7e/0x90
__kmalloc_node_track_caller+0x52/0x1b0
kstrdup+0x3b/0x70
cifs_get_tcp_session+0xbc/0x19b0
mount_get_conns+0xa9/0x10c0
cifs_mount+0xdf/0x1970
cifs_smb3_do_mount+0x295/0x1660
smb3_get_tree+0x352/0x5e0
vfs_get_tree+0x8e/0x2e0
path_mount+0xf8c/0x1990
do_mount+0xee/0x110
__x64_sys_mount+0x14b/0x1f0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 477:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x50
__kasan_slab_free+0x10a/0x190
__kmem_cache_free+0xca/0x3f0
cifs_put_tcp_session+0x30c/0x450
cifs_mount+0xf95/0x1970
cifs_smb3_do_mount+0x295/0x1660
smb3_get_tree+0x352/0x5e0
vfs_get_tree+0x8e/0x2e0
path_mount+0xf8c/0x1990
do_mount+0xee/0x110
__x64_sys_mount+0x14b/0x1f0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff888108f35380
which belongs to the cache kmalloc-16 of size 16
The buggy address is located 0 bytes inside of
16-byte region [ffff888108f35380, ffff888108f35390)
The buggy address belongs to the physical page:
page:00000000333f8e58 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888108f350e0 pfn:0x108f35
flags: 0x200000000000200(slab|node=0|zone=2)
raw: 0200000000000200 0000000000000000 dead000000000122 ffff8881000423c0
raw: ffff888108f350e0 000000008080007a 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888108f35280: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
ffff888108f35300: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
>ffff888108f35380: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
^
ffff888108f35400: fa fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888108f35480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
Fixes: 7be3248f31 ("cifs: To match file servers, make sure the server hostname matches")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
