This reverts commit 81c7c0a350. The idea
to make write method mandatory was flawed as several client drivers
(such as atkbd) check for presence of write() method to adjust behavior
of the driver.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Even though we validate user-provided inputs we then traverse past
validated data when applying the new map. The issue was originally
discovered by Murray McAllister with this simple POC (if the following
is executed by an unprivileged user it will instantly panic the system):
int main(void) {
int fd, ret;
unsigned int buffer[10000];
fd = open("/dev/input/js0", O_RDONLY);
if (fd == -1)
printf("Error opening file\n");
ret = ioctl(fd, JSIOCSBTNMAP & ~IOCSIZE_MASK, &buffer);
printf("%d\n", ret);
}
The solution is to traverse internal buffer which is guaranteed to only
contain valid date when constructing the map.
Fixes: 182d679b22 ("Input: joydev - prevent potential read overflow in ioctl")
Fixes: 999b874f4a ("Input: joydev - validate axis/button maps before clobbering current ones")
Reported-by: Murray McAllister <murray.mcallister@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Alexander Larkin <avlarkin82@gmail.com>
Link: https://lore.kernel.org/r/20210620120030.1513655-1-avlarkin82@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This reverts commits 4bad58ebc8 (and
399f8dd9a8, which tried to fix it).
I do not believe these are correct, and I'm about to release 5.13, so am
reverting them out of an abundance of caution.
The locking is odd, and appears broken.
On the allocation side (in __sigqueue_alloc()), the locking is somewhat
straightforward: it depends on sighand->siglock. Since one caller
doesn't hold that lock, it further then tests 'sigqueue_flags' to avoid
the case with no locks held.
On the freeing side (in sigqueue_cache_or_free()), there is no locking
at all, and the logic instead depends on 'current' being a single
thread, and not able to race with itself.
To make things more exciting, there's also the data race between freeing
a signal and allocating one, which is handled by using WRITE_ONCE() and
READ_ONCE(), and being mutually exclusive wrt the initial state (ie
freeing will only free if the old state was NULL, while allocating will
obviously only use the value if it was non-NULL, so only one or the
other will actually act on the value).
However, while the free->alloc paths do seem mutually exclusive thanks
to just the data value dependency, it's not clear what the memory
ordering constraints are on it. Could writes from the previous
allocation possibly be delayed and seen by the new allocation later,
causing logical inconsistencies?
So it's all very exciting and unusual.
And in particular, it seems that the freeing side is incorrect in
depending on "current" being single-threaded. Yes, 'current' is a
single thread, but in the presense of asynchronous events even a single
thread can have data races.
And such asynchronous events can and do happen, with interrupts causing
signals to be flushed and thus free'd (for example - sending a
SIGCONT/SIGSTOP can happen from interrupt context, and can flush
previously queued process control signals).
So regardless of all the other questions about the memory ordering and
locking for this new cached allocation, the sigqueue_cache_or_free()
assumptions seem to be fundamentally incorrect.
It may be that people will show me the errors of my ways, and tell me
why this is all safe after all. We can reinstate it if so. But my
current belief is that the WRITE_ONCE() that sets the cached entry needs
to be a smp_store_release(), and the READ_ONCE() that finds a cached
entry needs to be a smp_load_acquire() to handle memory ordering
correctly.
And the sequence in sigqueue_cache_or_free() would need to either use a
lock or at least be interrupt-safe some way (perhaps by using something
like the percpu 'cmpxchg': it doesn't need to be SMP-safe, but like the
percpu operations it needs to be interrupt-safe).
Fixes: 399f8dd9a8 ("signal: Prevent sigqueue caching after task got released")
Fixes: 4bad58ebc8 ("signal: Allow tasks to cache one sigqueue struct")
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull s390 fixes from Vasily Gorbik:
- Fix a couple of late pt_regs flags handling findings of conversion to
generic entry.
- Fix potential register clobbering in stack switch helper.
- Fix thread/group masks for offline cpus.
- Fix cleanup of mdev resources when remove callback is invoked in
vfio-ap code.
* tag 's390-5.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/stack: fix possible register corruption with stack switch helper
s390/topology: clear thread/group maps for offline cpus
s390/vfio-ap: clean up mdev resources when remove callback invoked
s390: clear pt_regs::flags on irq entry
s390: fix system call restart with multiple signals
Pull pin control fixes from Linus Walleij:
"Two last-minute fixes:
- Put an fwnode in the errorpath in the SGPIO driver
- Fix the number of GPIO lines per bank in the STM32 driver"
* tag 'pinctrl-v5.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: stm32: fix the reported number of GPIO lines per bank
pinctrl: microchip-sgpio: Put fwnode in error case during ->probe()
Pull SCSI fixes from James Bottomley:
"Two small fixes, both in upper layer drivers (scsi disk and cdrom).
The sd one is fixing a commit changing revalidation that came from the
block tree a while ago (5.10) and the sr one adds handling of a
condition we didn't previously handle for manually removed media"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: sd: Call sd_revalidate_disk() for ioctl(BLKRRPART)
scsi: sr: Return appropriate error code when disk is ejected
Merge misc fixes from Andrew Morton:
"24 patches, based on 4a09d388f2.
Subsystems affected by this patch series: mm (thp, vmalloc, hugetlb,
memory-failure, and pagealloc), nilfs2, kthread, MAINTAINERS, and
mailmap"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (24 commits)
mailmap: add Marek's other e-mail address and identity without diacritics
MAINTAINERS: fix Marek's identity again
mm/page_alloc: do bulk array bounds check after checking populated elements
mm/page_alloc: __alloc_pages_bulk(): do bounds check before accessing array
mm/hwpoison: do not lock page again when me_huge_page() successfully recovers
mm,hwpoison: return -EHWPOISON to denote that the page has already been poisoned
mm/memory-failure: use a mutex to avoid memory_failure() races
mm, futex: fix shared futex pgoff on shmem huge page
kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync()
kthread_worker: split code for canceling the delayed work timer
mm/vmalloc: unbreak kasan vmalloc support
KVM: s390: prepare for hugepage vmalloc
mm/vmalloc: add vmalloc_no_huge
nilfs2: fix memory leak in nilfs_sysfs_delete_device_group
mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk()
mm/thp: fix page_vma_mapped_walk() if THP mapped by ptes
mm: page_vma_mapped_walk(): get vma_address_end() earlier
mm: page_vma_mapped_walk(): use goto instead of while (1)
mm: page_vma_mapped_walk(): add a level of indentation
mm: page_vma_mapped_walk(): crossing page table boundary
...
This ioctl request reads from uffdio_continue structure written by
userspace which justifies _IOC_WRITE flag. It also writes back to that
structure which justifies _IOC_READ flag.
See NOTEs in include/uapi/asm-generic/ioctl.h for more information.
Fixes: f619147104 ("userfaultfd: add UFFDIO_CONTINUE ioctl")
Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Reviewed-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull i2c fixes from Wolfram Sang:
"Three more driver bugfixes and an annotation fix for the core"
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: robotfuzz-osif: fix control-request directions
i2c: dev: Add __user annotation
i2c: cp2615: check for allocation failure in cp2615_i2c_recv()
i2c: i801: Ensure that SMBHSTSTS_INUSE_STS is cleared when leaving i801_access
Pull device properties framework fix from Rafael Wysocki:
"Fix a NULL pointer dereference introduced by a recent commit and
occurring when device_remove_software_node() is used with a device
that has never been registered (Heikki Krogerus)"
* tag 'devprop-5.13-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
software node: Handle software node injection to an existing device properly
Pull xen fix from Juergen Gross:
"A fix for a regression introduced in 5.12: when migrating an irq
related to a Xen user event to another cpu, a race might result
in a WARN() triggering"
* tag 'for-linus-5.13b-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/events: reset active flag for lateeoi events later
Pull kvm fixes from Paolo Bonzini:
"A selftests fix for ARM, and the fix for page reference count
underflow. This is a very small fix that was provided by Nick Piggin
and tested by myself"
* tag 'for-linus-urgent' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: do not allow mapping valid but non-reference-counted pages
KVM: selftests: Fix mapping length truncation in m{,un}map()
Pull x86 fixes from Borislav Petkov:
"Two more urgent FPU fixes:
- prevent unprivileged userspace from reinitializing supervisor
states
- prepare init_fpstate, which is the buffer used when initializing
FPU state, properly in case the skip-writing-state-components
XSAVE* variants are used"
* tag 'x86_urgent_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Make init_fpstate correct with optimized XSAVE
x86/fpu: Preserve supervisor states in sanitize_restored_user_xstate()
Pull ceph fixes from Ilya Dryomov:
"Two regression fixes from the merge window: one in the auth code
affecting old clusters and one in the filesystem for proper
propagation of MDS request errors.
Also included a locking fix for async creates, marked for stable"
* tag 'ceph-for-5.13-rc8' of https://github.com/ceph/ceph-client:
libceph: set global_id as soon as we get an auth ticket
libceph: don't pass result into ac->ops->handle_reply()
ceph: fix error handling in ceph_atomic_open and ceph_lookup
ceph: must hold snap_rwsem when filling inode for async create
Pull netfs fixes from David Howells:
"This contains patches to fix netfs_write_begin() and afs_write_end()
in the following ways:
(1) In netfs_write_begin(), extract the decision about whether to skip
a page out to its own helper and have that clear around the region
to be written, but not clear that region. This requires the
filesystem to patch it up afterwards if the hole doesn't get
completely filled.
(2) Use offset_in_thp() in (1) rather than manually calculating the
offset into the page.
(3) Due to (1), afs_write_end() now needs to handle short data write
into the page by generic_perform_write(). I've adopted an
analogous approach to ceph of just returning 0 in this case and
letting the caller go round again.
It also adds a note that (in the future) the len parameter may extend
beyond the page allocated. This is because the page allocation is
deferred to write_begin() and that gets to decide what size of THP to
allocate."
Jeff Layton points out:
"The netfs fix in particular fixes a data corruption bug in cephfs"
* tag 'netfs-fixes-20210621' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
netfs: fix test for whether we can skip read when writing beyond EOF
afs: Fix afs_write_end() to handle short writes
Pull gpio fixes from Bartosz Golaszewski:
- fix wake-up interrupt support on gpio-mxc
- zero the padding bytes in a structure passed to user-space in the
GPIO character device
- require HAS_IOPORT_MAP in two drivers that need it to fix a Kbuild
issue
* tag 'gpio-fixes-for-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
gpio: AMD8111 and TQMX86 require HAS_IOPORT_MAP
gpiolib: cdev: zero padding during conversion to gpioline_info_changed
gpio: mxc: Fix disabled interrupt wake-up support
Pull sound fixes from Takashi Iwai:
"Two small changes have been cherry-picked as a last material for 5.13:
a coverage after UMN revert action and a stale MAINTAINERS entry fix"
* tag 'sound-5.13-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
MAINTAINERS: remove Timur Tabi from Freescale SOC sound drivers
ASoC: rt5645: Avoid upgrading static warnings to errors
Both of these drivers use ioport_map(), so they need to
depend on HAS_IOPORT_MAP. Otherwise, they cannot be built
even with COMPILE_TEST on architectures without an ioport
implementation, such as ARCH=um.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Dan Carpenter reported the following
The patch 0f87d9d30f: "mm/page_alloc: add an array-based interface
to the bulk page allocator" from Apr 29, 2021, leads to the following
static checker warning:
mm/page_alloc.c:5338 __alloc_pages_bulk()
warn: potentially one past the end of array 'page_array[nr_populated]'
The problem can occur if an array is passed in that is fully populated.
That potentially ends up allocating a single page and storing it past
the end of the array. This patch returns 0 if the array is fully
populated.
Link: https://lkml.kernel.org/r/20210618125102.GU30378@techsingularity.net
Fixes: 0f87d9d30f ("mm/page_alloc: add an array-based interface to the bulk page allocator")
Signed-off-by: Mel Gorman <mgorman@techsinguliarity.net>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
