Commit Graph

219 Commits

Author SHA1 Message Date
Greg Kroah-Hartman baca54d956 Merge 5.6-rc7 into char-misc-next
We need the char/misc driver fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-23 07:59:38 +01:00
Christian Brauner 095cf502b3 binderfs: port to new mount api
When I first wrote binderfs the new mount api had not yet landed. Now
that it has been around for a little while and a bunch of filesystems
have already been ported we should do so too. When Al sent his
mount-api-conversion pr he requested that binderfs (and a few others) be
ported separately. It's time we port binderfs. We can make use of the
new option parser, get nicer infrastructure and it will be easier if we
ever add any new mount options.

This survives testing with the binderfs selftests:

for i in `seq 1 1000`; do ./binderfs_test; done

including the new stress tests I sent out for review today:

 TAP version 13
 1..1
 # selftests: filesystems/binderfs: binderfs_test
 # [==========] Running 3 tests from 1 test cases.
 # [ RUN      ] global.binderfs_stress
 # [  XFAIL!  ] Tests are not run as root. Skipping privileged tests
 # [==========] Running 3 tests from 1 test cases.
 # [ RUN      ] global.binderfs_stress
 # [       OK ] global.binderfs_stress
 # [ RUN      ] global.binderfs_test_privileged
 # [       OK ] global.binderfs_test_privileged
 # [ RUN      ] global.binderfs_test_unprivileged
 # # Allocated new binder device with major 243, minor 4, and name my-binder
 # # Detected binder version: 8
 # [==========] Running 3 tests from 1 test cases.
 # [ RUN      ] global.binderfs_stress
 # [       OK ] global.binderfs_stress
 # [ RUN      ] global.binderfs_test_privileged
 # [       OK ] global.binderfs_test_privileged
 # [ RUN      ] global.binderfs_test_unprivileged
 # [       OK ] global.binderfs_test_unprivileged
 # [==========] 3 / 3 tests passed.
 # [  PASSED  ]
 ok 1 selftests: filesystems/binderfs: binderfs_test

Cc: Todd Kjos <tkjos@google.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200313153427.141789-1-christian.brauner@ubuntu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-19 07:41:01 +01:00
Christian Brauner 211b64e4b5 binderfs: use refcount for binder control devices too
Binderfs binder-control devices are cleaned up via binderfs_evict_inode
too() which will use refcount_dec_and_test(). However, we missed to set
the refcount for binderfs binder-control devices and so we underflowed
when the binderfs instance got unmounted. Pretty obvious oversight and
should have been part of the more general UAF fix. The good news is that
having test cases (suprisingly) helps.

Technically, we could detect that we're about to cleanup the
binder-control dentry in binderfs_evict_inode() and then simply clean it
up. But that makes the assumption that the binder driver itself will
never make use of a binderfs binder-control device after the binderfs
instance it belongs to has been unmounted and the superblock for it been
destroyed. While it is unlikely to ever come to this let's be on the
safe side. Performance-wise this also really doesn't matter since the
binder-control device is only every really when creating the binderfs
filesystem or creating additional binder devices. Both operations are
pretty rare.

Fixes: f0fe2c0f05 ("binder: prevent UAF for binderfs devices II")
Link: https://lore.kernel.org/r/CA+G9fYusdfg7PMfC9Xce-xLT7NiyKSbgojpK35GOm=Pf9jXXrA@mail.gmail.com
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20200311105309.1742827-1-christian.brauner@ubuntu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11 19:33:52 +01:00
Christian Brauner f0fe2c0f05 binder: prevent UAF for binderfs devices II
This is a necessary follow up to the first fix I proposed and we merged
in 2669b8b0c7 ("binder: prevent UAF for binderfs devices"). I have been
overly optimistic that the simple fix I proposed would work. But alas,
ihold() + iput() won't work since the inodes won't survive the
destruction of the superblock.
So all we get with my prior fix is a different race with a tinier
race-window but it doesn't solve the issue. Fwiw, the problem lies with
generic_shutdown_super(). It even has this cozy Al-style comment:

          if (!list_empty(&sb->s_inodes)) {
                  printk("VFS: Busy inodes after unmount of %s. "
                     "Self-destruct in 5 seconds.  Have a nice day...\n",
                     sb->s_id);
          }

On binder_release(), binder_defer_work(proc, BINDER_DEFERRED_RELEASE) is
called which punts the actual cleanup operation to a workqueue. At some
point, binder_deferred_func() will be called which will end up calling
binder_deferred_release() which will retrieve and cleanup the
binder_context attach to this struct binder_proc.

If we trace back where this binder_context is attached to binder_proc we
see that it is set in binder_open() and is taken from the struct
binder_device it is associated with. This obviously assumes that the
struct binder_device that context is attached to is _never_ freed. While
that might be true for devtmpfs binder devices it is most certainly
wrong for binderfs binder devices.

So, assume binder_open() is called on a binderfs binder devices. We now
stash away the struct binder_context associated with that struct
binder_devices:
	proc->context = &binder_dev->context;
	/* binderfs stashes devices in i_private */
	if (is_binderfs_device(nodp)) {
		binder_dev = nodp->i_private;
		info = nodp->i_sb->s_fs_info;
		binder_binderfs_dir_entry_proc = info->proc_log_dir;
	} else {
	.
	.
	.
	proc->context = &binder_dev->context;

Now let's assume that the binderfs instance for that binder devices is
shutdown via umount() and/or the mount namespace associated with it goes
away. As long as there is still an fd open for that binderfs binder
device things are fine. But let's assume we now close the last fd for
that binderfs binder device. Now binder_release() is called and punts to
the workqueue. Assume that the workqueue has quite a bit of stuff to do
and doesn't get to cleaning up the struct binder_proc and the associated
struct binder_context with it for that binderfs binder device right
away. In the meantime, the VFS is killing the super block and is
ultimately calling sb->evict_inode() which means it will call
binderfs_evict_inode() which does:

static void binderfs_evict_inode(struct inode *inode)
{
	struct binder_device *device = inode->i_private;
	struct binderfs_info *info = BINDERFS_I(inode);

	clear_inode(inode);

	if (!S_ISCHR(inode->i_mode) || !device)
		return;

	mutex_lock(&binderfs_minors_mutex);
	--info->device_count;
	ida_free(&binderfs_minors, device->miscdev.minor);
	mutex_unlock(&binderfs_minors_mutex);

	kfree(device->context.name);
	kfree(device);
}

thereby freeing the struct binder_device including struct
binder_context.

Now the workqueue finally has time to get around to cleaning up struct
binder_proc and is now trying to access the associate struct
binder_context. Since it's already freed it will OOPs.

Fix this by introducing a refounct on binder devices.

This is an alternative fix to 51d8a7eca6 ("binder: prevent UAF read in
print_binder_transaction_log_entry()").

Fixes: 3ad20fe393 ("binder: implement binderfs")
Fixes: 2669b8b0c7 ("binder: prevent UAF for binderfs devices")
Fixes: 03e2e07e38 ("binder: Make transaction_log available in binderfs")
Related : 51d8a7eca6 ("binder: prevent UAF read in print_binder_transaction_log_entry()")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20200303164340.670054-1-christian.brauner@ubuntu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-03 19:58:37 +01:00
Christian Brauner 2669b8b0c7 binder: prevent UAF for binderfs devices
On binder_release(), binder_defer_work(proc, BINDER_DEFERRED_RELEASE) is
called which punts the actual cleanup operation to a workqueue. At some
point, binder_deferred_func() will be called which will end up calling
binder_deferred_release() which will retrieve and cleanup the
binder_context attach to this struct binder_proc.

If we trace back where this binder_context is attached to binder_proc we
see that it is set in binder_open() and is taken from the struct
binder_device it is associated with. This obviously assumes that the
struct binder_device that context is attached to is _never_ freed. While
that might be true for devtmpfs binder devices it is most certainly
wrong for binderfs binder devices.

So, assume binder_open() is called on a binderfs binder devices. We now
stash away the struct binder_context associated with that struct
binder_devices:
	proc->context = &binder_dev->context;
	/* binderfs stashes devices in i_private */
	if (is_binderfs_device(nodp)) {
		binder_dev = nodp->i_private;
		info = nodp->i_sb->s_fs_info;
		binder_binderfs_dir_entry_proc = info->proc_log_dir;
	} else {
	.
	.
	.
	proc->context = &binder_dev->context;

Now let's assume that the binderfs instance for that binder devices is
shutdown via umount() and/or the mount namespace associated with it goes
away. As long as there is still an fd open for that binderfs binder
device things are fine. But let's assume we now close the last fd for
that binderfs binder device. Now binder_release() is called and punts to
the workqueue. Assume that the workqueue has quite a bit of stuff to do
and doesn't get to cleaning up the struct binder_proc and the associated
struct binder_context with it for that binderfs binder device right
away. In the meantime, the VFS is killing the super block and is
ultimately calling sb->evict_inode() which means it will call
binderfs_evict_inode() which does:

static void binderfs_evict_inode(struct inode *inode)
{
	struct binder_device *device = inode->i_private;
	struct binderfs_info *info = BINDERFS_I(inode);

	clear_inode(inode);

	if (!S_ISCHR(inode->i_mode) || !device)
		return;

	mutex_lock(&binderfs_minors_mutex);
	--info->device_count;
	ida_free(&binderfs_minors, device->miscdev.minor);
	mutex_unlock(&binderfs_minors_mutex);

	kfree(device->context.name);
	kfree(device);
}

thereby freeing the struct binder_device including struct
binder_context.

Now the workqueue finally has time to get around to cleaning up struct
binder_proc and is now trying to access the associate struct
binder_context. Since it's already freed it will OOPs.

Fix this by holding an additional reference to the inode that is only
released once the workqueue is done cleaning up struct binder_proc. This
is an easy alternative to introducing separate refcounting on struct
binder_device which we can always do later if it becomes necessary.

This is an alternative fix to 51d8a7eca6 ("binder: prevent UAF read in
print_binder_transaction_log_entry()").

Fixes: 3ad20fe393 ("binder: implement binderfs")
Fixes: 03e2e07e38 ("binder: Make transaction_log available in binderfs")
Related : 51d8a7eca6 ("binder: prevent UAF read in print_binder_transaction_log_entry()")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-03 08:02:57 +01:00
Linus Torvalds 896f8d23d0 for-5.6/io_uring-vfs-2020-01-29
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Merge tag 'for-5.6/io_uring-vfs-2020-01-29' of git://git.kernel.dk/linux-block

Pull io_uring updates from Jens Axboe:

 - Support for various new opcodes (fallocate, openat, close, statx,
   fadvise, madvise, openat2, non-vectored read/write, send/recv, and
   epoll_ctl)

 - Faster ring quiesce for fileset updates

 - Optimizations for overflow condition checking

 - Support for max-sized clamping

 - Support for probing what opcodes are supported

 - Support for io-wq backend sharing between "sibling" rings

 - Support for registering personalities

 - Lots of little fixes and improvements

* tag 'for-5.6/io_uring-vfs-2020-01-29' of git://git.kernel.dk/linux-block: (64 commits)
  io_uring: add support for epoll_ctl(2)
  eventpoll: support non-blocking do_epoll_ctl() calls
  eventpoll: abstract out epoll_ctl() handler
  io_uring: fix linked command file table usage
  io_uring: support using a registered personality for commands
  io_uring: allow registering credentials
  io_uring: add io-wq workqueue sharing
  io-wq: allow grabbing existing io-wq
  io_uring/io-wq: don't use static creds/mm assignments
  io-wq: make the io_wq ref counted
  io_uring: fix refcounting with batched allocations at OOM
  io_uring: add comment for drain_next
  io_uring: don't attempt to copy iovec for READ/WRITE
  io_uring: honor IOSQE_ASYNC for linked reqs
  io_uring: prep req when do IOSQE_ASYNC
  io_uring: use labeled array init in io_op_defs
  io_uring: optimise sqe-to-req flags translation
  io_uring: remove REQ_F_IO_DRAINED
  io_uring: file switch work needs to get flushed on exit
  io_uring: hide uring_fd in ctx
  ...
2020-01-29 18:53:37 -08:00
Martin Fuzzey eb143f8756 binder: fix log spam for existing debugfs file creation.
Since commit 43e23b6c0b ("debugfs: log errors when something goes wrong")
debugfs logs attempts to create existing files.

However binder attempts to create multiple debugfs files with
the same name when a single PID has multiple contexts, this leads
to log spamming during an Android boot (17 such messages during
boot on my system).

Fix this by checking if we already know the PID and only create
the debugfs entry for the first context per PID.

Do the same thing for binderfs for symmetry.

Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
Acked-by: Todd Kjos <tkjos@google.com>
Fixes: 43e23b6c0b ("debugfs: log errors when something goes wrong")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1578671054-5982-1-git-send-email-martin.fuzzey@flowbird.group
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-22 15:14:24 +01:00
Jens Axboe 6e802a4ba0 fs: move filp_close() outside of __close_fd_get_file()
Just one caller of this, and just use filp_close() there manually.
This is important to allow async close/removal of the fd.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-20 17:01:53 -07:00
Todd Kjos 1698174271 binder: fix incorrect calculation for num_valid
For BINDER_TYPE_PTR and BINDER_TYPE_FDA transactions, the
num_valid local was calculated incorrectly causing the
range check in binder_validate_ptr() to miss out-of-bounds
offsets.

Fixes: bde4a19fc0 ("binder: use userspace pointer as base of buffer space")
Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191213202531.55010-1-tkjos@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-14 09:10:47 +01:00
Linus Torvalds 0da522107e compat_ioctl: remove most of fs/compat_ioctl.c
As part of the cleanup of some remaining y2038 issues, I came to
 fs/compat_ioctl.c, which still has a couple of commands that need support
 for time64_t.
 
 In completely unrelated work, I spent time on cleaning up parts of this
 file in the past, moving things out into drivers instead.
 
 After Al Viro reviewed an earlier version of this series and did a lot
 more of that cleanup, I decided to try to completely eliminate the rest
 of it and move it all into drivers.
 
 This series incorporates some of Al's work and many patches of my own,
 but in the end stops short of actually removing the last part, which is
 the scsi ioctl handlers. I have patches for those as well, but they need
 more testing or possibly a rewrite.
 
 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Merge tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann:
 "As part of the cleanup of some remaining y2038 issues, I came to
  fs/compat_ioctl.c, which still has a couple of commands that need
  support for time64_t.

  In completely unrelated work, I spent time on cleaning up parts of
  this file in the past, moving things out into drivers instead.

  After Al Viro reviewed an earlier version of this series and did a lot
  more of that cleanup, I decided to try to completely eliminate the
  rest of it and move it all into drivers.

  This series incorporates some of Al's work and many patches of my own,
  but in the end stops short of actually removing the last part, which
  is the scsi ioctl handlers. I have patches for those as well, but they
  need more testing or possibly a rewrite"

* tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits)
  scsi: sd: enable compat ioctls for sed-opal
  pktcdvd: add compat_ioctl handler
  compat_ioctl: move SG_GET_REQUEST_TABLE handling
  compat_ioctl: ppp: move simple commands into ppp_generic.c
  compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t
  compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic
  compat_ioctl: unify copy-in of ppp filters
  tty: handle compat PPP ioctls
  compat_ioctl: move SIOCOUTQ out of compat_ioctl.c
  compat_ioctl: handle SIOCOUTQNSD
  af_unix: add compat_ioctl support
  compat_ioctl: reimplement SG_IO handling
  compat_ioctl: move WDIOC handling into wdt drivers
  fs: compat_ioctl: move FITRIM emulation into file systems
  gfs2: add compat_ioctl support
  compat_ioctl: remove unused convert_in_user macro
  compat_ioctl: remove last RAID handling code
  compat_ioctl: remove /dev/raw ioctl translation
  compat_ioctl: remove PCI ioctl translation
  compat_ioctl: remove joystick ioctl translation
  ...
2019-12-01 13:46:15 -08:00
Jann Horn 2a9edd056e binder: Handle start==NULL in binder_update_page_range()
The old loop wouldn't stop when reaching `start` if `start==NULL`, instead
continuing backwards to index -1 and crashing.

Luckily you need to be highly privileged to map things at NULL, so it's not
a big problem.

Fix it by adjusting the loop so that the loop variable is always in bounds.

This patch is deliberately minimal to simplify backporting, but IMO this
function could use a refactor. The jump labels in the second loop body are
horrible (the error gotos should be jumping to free_range instead), and
both loops would look nicer if they just iterated upwards through indices.
And the up_read()+mmput() shouldn't be duplicated like that.

Cc: stable@vger.kernel.org
Fixes: 457b9a6f09 ("Staging: android: add binder driver")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191018205631.248274-3-jannh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-14 11:44:47 +08:00
Jann Horn a7a74d7ff5 binder: Prevent repeated use of ->mmap() via NULL mapping
binder_alloc_mmap_handler() attempts to detect the use of ->mmap() on a
binder_proc whose binder_alloc has already been initialized by checking
whether alloc->buffer is non-zero.

Before commit 880211667b ("binder: remove kernel vm_area for buffer
space"), alloc->buffer was a kernel mapping address, which is always
non-zero, but since that commit, it is a userspace mapping address.

A sufficiently privileged user can map /dev/binder at NULL, tricking
binder_alloc_mmap_handler() into assuming that the binder_proc has not been
mapped yet. This leads to memory unsafety.
Luckily, no context on Android has such privileges, and on a typical Linux
desktop system, you need to be root to do that.

Fix it by using the mapping size instead of the mapping address to
distinguish the mapped case. A valid VMA can't have size zero.

Fixes: 880211667b ("binder: remove kernel vm_area for buffer space")
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191018205631.248274-2-jannh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-14 11:44:47 +08:00
Jann Horn 8eb52a1ee3 binder: Fix race between mmap() and binder_alloc_print_pages()
binder_alloc_print_pages() iterates over
alloc->pages[0..alloc->buffer_size-1] under alloc->mutex.
binder_alloc_mmap_handler() writes alloc->pages and alloc->buffer_size
without holding that lock, and even writes them before the last bailout
point.

Unfortunately we can't take the alloc->mutex in the ->mmap() handler
because mmap_sem can be taken while alloc->mutex is held.
So instead, we have to locklessly check whether the binder_alloc has been
fully initialized with binder_alloc_get_vma(), like in
binder_alloc_new_buf_locked().

Fixes: 8ef4665aa1 ("android: binder: Add page usage in binder stats")
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191018205631.248274-1-jannh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-14 11:44:46 +08:00
Greg Kroah-Hartman da80d2e516 Merge 5.4-rc5 into char-misc-next
We want the binder fix in here as well for testing and to work on top
of.

Also handles a merge issue in binder.c to help linux-next out

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-27 18:48:33 +01:00
Arnd Bergmann 1832f2d8ff compat_ioctl: move more drivers to compat_ptr_ioctl
The .ioctl and .compat_ioctl file operations have the same prototype so
they can both point to the same function, which works great almost all
the time when all the commands are compatible.

One exception is the s390 architecture, where a compat pointer is only
31 bit wide, and converting it into a 64-bit pointer requires calling
compat_ptr(). Most drivers here will never run in s390, but since we now
have a generic helper for it, it's easy enough to use it consistently.

I double-checked all these drivers to ensure that all ioctl arguments
are used as pointers or are ignored, but are not interpreted as integer
values.

Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Darren Hart (VMware) <dvhart@infradead.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-23 17:23:44 +02:00
Jann Horn 834c7360f9 binder: Remove incorrect comment about vm_insert_page() behavior
vm_insert_page() does increment the page refcount, and just to be sure,
I've confirmed it by printing page_count(page[0].page_ptr) before and after
vm_insert_page(). It's 1 before, 2 afterwards, as expected.

Fixes: a145dd411e ("VM: add "vm_insert_page()" function")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191018153946.128584-1-jannh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-21 12:30:49 -04:00
Jann Horn 990be74764 binder: Use common definition of SZ_1K
SZ_1K has been defined in include/linux/sizes.h since v3.6. Get rid of the
duplicate definition.

Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191016150119.154756-2-jannh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-17 06:00:43 -07:00
Jann Horn 45d02f79b5 binder: Don't modify VMA bounds in ->mmap handler
binder_mmap() tries to prevent the creation of overly big binder mappings
by silently truncating the size of the VMA to 4MiB. However, this violates
the API contract of mmap(). If userspace attempts to create a large binder
VMA, and later attempts to unmap that VMA, it will call munmap() on a range
beyond the end of the VMA, which may have been allocated to another VMA in
the meantime. This can lead to userspace memory corruption.

The following sequence of calls leads to a segfault without this commit:

int main(void) {
  int binder_fd = open("/dev/binder", O_RDWR);
  if (binder_fd == -1) err(1, "open binder");
  void *binder_mapping = mmap(NULL, 0x800000UL, PROT_READ, MAP_SHARED,
                              binder_fd, 0);
  if (binder_mapping == MAP_FAILED) err(1, "mmap binder");
  void *data_mapping = mmap(NULL, 0x400000UL, PROT_READ|PROT_WRITE,
                            MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  if (data_mapping == MAP_FAILED) err(1, "mmap data");
  munmap(binder_mapping, 0x800000UL);
  *(char*)data_mapping = 1;
  return 0;
}

Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191016150119.154756-1-jannh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-17 05:58:44 -07:00
Joel Fernandes (Google) 5dc54a06f6 binder: Fix comment headers on binder_alloc_prepare_to_free()
binder_alloc_buffer_lookup() doesn't exist and is named
"binder_alloc_prepare_to_free()". Correct the code comments to reflect
this.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20190930201250.139554-1-joel@joelfernandes.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-10 14:39:23 +02:00
Christian Brauner 51d8a7eca6 binder: prevent UAF read in print_binder_transaction_log_entry()
When a binder transaction is initiated on a binder device coming from a
binderfs instance, a pointer to the name of the binder device is stashed
in the binder_transaction_log_entry's context_name member. Later on it
is used to print the name in print_binder_transaction_log_entry(). By
the time print_binder_transaction_log_entry() accesses context_name
binderfs_evict_inode() might have already freed the associated memory
thereby causing a UAF. Do the simple thing and prevent this by copying
the name of the binder device instead of stashing a pointer to it.

Reported-by: Jann Horn <jannh@google.com>
Fixes: 03e2e07e38 ("binder: Make transaction_log available in binderfs")
Link: https://lore.kernel.org/r/CAG48ez14Q0-F8LqsvcNbyR2o6gPW8SHXsm4u5jmD9MpsteM2Tw@mail.gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Todd Kjos <tkjos@google.com>
Reviewed-by: Hridya Valsaraju <hridya@google.com>
Link: https://lore.kernel.org/r/20191008130159.10161-1-christian.brauner@ubuntu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-10 14:39:22 +02:00
Hridya Valsaraju 4feb80faf4 binder: Add binder_proc logging to binderfs
Currently /sys/kernel/debug/binder/proc contains
the debug data for every binder_proc instance.
This patch makes this information also available
in a binderfs instance mounted with a mount option
"stats=global" in addition to debugfs. The patch does
not affect the presence of the file in debugfs.

If a binderfs instance is mounted at path /dev/binderfs,
this file would be present at /dev/binderfs/binder_logs/proc.
This change provides an alternate way to access this file when debugfs
is not mounted.

Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Link: https://lore.kernel.org/r/20190903161655.107408-5-hridya@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04 13:31:26 +02:00
Hridya Valsaraju 03e2e07e38 binder: Make transaction_log available in binderfs
Currently, the binder transaction log files 'transaction_log'
and 'failed_transaction_log' live in debugfs at the following locations:

/sys/kernel/debug/binder/failed_transaction_log
/sys/kernel/debug/binder/transaction_log

This patch makes these files also available in a binderfs instance
mounted with the mount option "stats=global".
It does not affect the presence of these files in debugfs.
If a binderfs instance is mounted at path /dev/binderfs, the location of
these files will be as follows:

/dev/binderfs/binder_logs/failed_transaction_log
/dev/binderfs/binder_logs/transaction_log

This change provides an alternate option to access these files when
debugfs is not mounted.

Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Link: https://lore.kernel.org/r/20190903161655.107408-4-hridya@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04 13:31:22 +02:00
Hridya Valsaraju 0e13e452da binder: Add stats, state and transactions files
The following binder stat files currently live in debugfs.

/sys/kernel/debug/binder/state
/sys/kernel/debug/binder/stats
/sys/kernel/debug/binder/transactions

This patch makes these files available in a binderfs instance
mounted with the mount option 'stats=global'. For example, if a binderfs
instance is mounted at path /dev/binderfs, the above files will be
available at the following locations:

/dev/binderfs/binder_logs/state
/dev/binderfs/binder_logs/stats
/dev/binderfs/binder_logs/transactions

This provides a way to access them even when debugfs is not mounted.

Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20190903161655.107408-3-hridya@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04 13:31:18 +02:00
Hridya Valsaraju f00834518e binder: add a mount option to show global stats
Currently, all binder state and statistics live in debugfs.
We need this information even when debugfs is not mounted.
This patch adds the mount option 'stats' to enable a binderfs
instance to have binder debug information present in the same.
'stats=global' will enable the global binder statistics. In
the future, 'stats=local' will enable binder statistics local
to the binderfs instance. The two modes 'global' and 'local'
will be mutually exclusive. 'stats=global' option is only available
for a binderfs instance mounted in the initial user namespace.
An attempt to use the option to mount a binderfs instance in
another user namespace will return an EPERM error.

Signed-off-by: Hridya Valsaraju <hridya@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20190903161655.107408-2-hridya@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04 13:31:13 +02:00
Hridya Valsaraju ca2864c6e8 binder: Add default binder devices through binderfs when configured
Currently, since each binderfs instance needs its own
private binder devices, every time a binderfs instance is
mounted, all the default binder devices need to be created
via the BINDER_CTL_ADD IOCTL. This patch aims to
add a solution to automatically create the default binder
devices for each binderfs instance that gets mounted.
To achieve this goal, when CONFIG_ANDROID_BINDERFS is set,
the default binder devices specified by CONFIG_ANDROID_BINDER_DEVICES
are created in each binderfs instance instead of global devices
being created by the binder driver.

Co-developed-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20190808222727.132744-2-hridya@google.com
Link: https://lore.kernel.org/r/20190904110704.8606-2-christian.brauner@ubuntu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04 13:17:35 +02:00
Hridya Valsaraju 028fb5822b binder: Validate the default binderfs device names.
Length of a binderfs device name cannot exceed BINDERFS_MAX_NAME.
This patch adds a check in binderfs_init() to ensure the same
for the default binder devices that will be created in every
binderfs instance.

Co-developed-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20190808222727.132744-3-hridya@google.com
Link: https://lore.kernel.org/r/20190904110704.8606-3-christian.brauner@ubuntu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04 13:17:35 +02:00
Hridya Valsaraju 49ed96943a binder: prevent transactions to context manager from its own process.
Currently, a transaction to context manager from its own process
is prevented by checking if its binder_proc struct is the same as
that of the sender. However, this would not catch cases where the
process opens the binder device again and uses the new fd to send
a transaction to the context manager.

Reported-by: syzbot+8b3c354d33c4ac78bfad@syzkaller.appspotmail.com
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190715191804.112933-1-hridya@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-24 11:02:28 +02:00
Martijn Coenen a565870650 binder: Set end of SG buffer area properly.
In case the target node requests a security context, the
extra_buffers_size is increased with the size of the security context.
But, that size is not available for use by regular scatter-gather
buffers; make sure the ending of that buffer is marked correctly.

Acked-by: Todd Kjos <tkjos@google.com>
Fixes: ec74136ded ("binder: create node flag to request sender's security context")
Signed-off-by: Martijn Coenen <maco@android.com>
Cc: stable@vger.kernel.org # 5.1+
Link: https://lore.kernel.org/r/20190709110923.220736-1-maco@android.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-24 11:02:10 +02:00
Todd Kjos bb4a2e48d5 binder: return errors from buffer copy functions
The buffer copy functions assumed the caller would ensure
correct alignment and that the memory to be copied was
completely within the binder buffer. There have been
a few cases discovered by syzkallar where a malformed
transaction created by a user could violated the
assumptions and resulted in a BUG_ON.

The fix is to remove the BUG_ON and always return the
error to be handled appropriately by the caller.

Acked-by: Martijn Coenen <maco@android.com>
Reported-by: syzbot+3ae18325f96190606754@syzkaller.appspotmail.com
Fixes: bde4a19fc0 ("binder: use userspace pointer as base of buffer space")
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-01 08:42:47 +02:00
Greg Kroah-Hartman 8083f3d788 Merge 5.2-rc6 into char-misc-next
We need the char-misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-23 09:23:33 +02:00
Todd Kjos 1909a671db binder: fix memory leak in error path
syzkallar found a 32-byte memory leak in a rarely executed error
case. The transaction complete work item was not freed if put_user()
failed when writing the BR_TRANSACTION_COMPLETE to the user command
buffer. Fixed by freeing it before put_user() is called.

Reported-by: syzbot+182ce46596c3f2e1eb24@syzkaller.appspotmail.com
Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22 11:49:16 +02:00
Todd Kjos a370003cc3 binder: fix possible UAF when freeing buffer
There is a race between the binder driver cleaning
up a completed transaction via binder_free_transaction()
and a user calling binder_ioctl(BC_FREE_BUFFER) to
release a buffer. It doesn't matter which is first but
they need to be protected against running concurrently
which can result in a UAF.

Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-13 10:35:55 +02:00
Thomas Gleixner 9c92ab6191 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282
Based on 1 normalized pattern(s):

  this software is licensed under the terms of the gnu general public
  license version 2 as published by the free software foundation and
  may be copied distributed and modified under those terms this
  program is distributed in the hope that it will be useful but
  without any warranty without even the implied warranty of
  merchantability or fitness for a particular purpose see the gnu
  general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 285 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00
Thomas Gleixner ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Linus Torvalds f678d6da74 Char/Misc patches for 5.2-rc1 - part 2
Here is the "real" big set of char/misc driver patches for 5.2-rc1
 
 Loads of different driver subsystem stuff in here, all over the places:
   - thunderbolt driver updates
   - habanalabs driver updates
   - nvmem driver updates
   - extcon driver updates
   - intel_th driver updates
   - mei driver updates
   - coresight driver updates
   - soundwire driver cleanups and updates
   - fastrpc driver updates
   - other minor driver updates
   - chardev minor fixups
 
 Feels like this tree is getting to be a dumping ground of "small driver
 subsystems" these days.  Which is fine with me, if it makes things
 easier for those subsystem maintainers.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.2-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc update part 2 from Greg KH:
 "Here is the "real" big set of char/misc driver patches for 5.2-rc1

  Loads of different driver subsystem stuff in here, all over the places:
   - thunderbolt driver updates
   - habanalabs driver updates
   - nvmem driver updates
   - extcon driver updates
   - intel_th driver updates
   - mei driver updates
   - coresight driver updates
   - soundwire driver cleanups and updates
   - fastrpc driver updates
   - other minor driver updates
   - chardev minor fixups

  Feels like this tree is getting to be a dumping ground of "small
  driver subsystems" these days. Which is fine with me, if it makes
  things easier for those subsystem maintainers.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.2-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits)
  intel_th: msu: Add current window tracking
  intel_th: msu: Add a sysfs attribute to trigger window switch
  intel_th: msu: Correct the block wrap detection
  intel_th: Add switch triggering support
  intel_th: gth: Factor out trace start/stop
  intel_th: msu: Factor out pipeline draining
  intel_th: msu: Switch over to scatterlist
  intel_th: msu: Replace open-coded list_{first,last,next}_entry variants
  intel_th: Only report useful IRQs to subdevices
  intel_th: msu: Start handling IRQs
  intel_th: pci: Use MSI interrupt signalling
  intel_th: Communicate IRQ via resource
  intel_th: Add "rtit" source device
  intel_th: Skip subdevices if their MMIO is missing
  intel_th: Rework resource passing between glue layers and core
  intel_th: SPDX-ify the documentation
  intel_th: msu: Fix single mode with IOMMU
  coresight: funnel: Support static funnel
  dt-bindings: arm: coresight: Unify funnel DT binding
  coresight: replicator: Add new device id for static replicator
  ...
2019-05-07 13:39:22 -07:00
Todd Kjos 0b0509508b binder: check for overflow when alloc for security context
When allocating space in the target buffer for the security context,
make sure the extra_buffers_size doesn't overflow. This can only
happen if the given size is invalid, but an overflow can turn it
into a valid size. Fail the transaction if an overflow is detected.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 21:26:49 +02:00
Tyler Hicks 60d4885710 binder: take read mode of mmap_sem in binder_alloc_free_page()
Restore the behavior of locking mmap_sem for reading in
binder_alloc_free_page(), as was first done in commit 3013bf62b6
("binder: reduce mmap_sem write-side lock"). That change was
inadvertently reverted by commit 5cec2d2e58 ("binder: fix race between
munmap() and direct reclaim").

In addition, change the name of the label for the error path to
accurately reflect that we're taking the lock for reading.

Backporting note: This fix is only needed when *both* of the commits
mentioned above are applied. That's an unlikely situation since they
both landed during the development of v5.1 but only one of them is
targeted for stable.

Fixes: 5cec2d2e58 ("binder: fix race between munmap() and direct reclaim")
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Todd Kjos <tkjos@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 11:53:43 +02:00
Todd Kjos 5cec2d2e58 binder: fix race between munmap() and direct reclaim
An munmap() on a binder device causes binder_vma_close() to be called
which clears the alloc->vma pointer.

If direct reclaim causes binder_alloc_free_page() to be called, there
is a race where alloc->vma is read into a local vma pointer and then
used later after the mm->mmap_sem is acquired. This can result in
calling zap_page_range() with an invalid vma which manifests as a
use-after-free in zap_page_range().

The fix is to check alloc->vma after acquiring the mmap_sem (which we
were acquiring anyway) and skip zap_page_range() if it has changed
to NULL.

Signed-off-by: Todd Kjos <tkjos@google.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-21 06:51:32 +01:00
Todd Kjos 5997da8214 binder: fix BUG_ON found by selinux-testsuite
The selinux-testsuite found an issue resulting in a BUG_ON()
where a conditional relied on a size_t going negative when
checking the validity of a buffer offset.

Fixes: 7a67a39320 ("binder: add function to copy binder object from buffer")
Reported-by: Paul Moore <paul@paul-moore.com>
Tested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-21 06:50:47 +01:00
Minchan Kim 3013bf62b6 binder: reduce mmap_sem write-side lock
binder has used write-side mmap_sem semaphore to release memory
mapped at address space of the process. However, right lock to
release pages is down_read, not down_write because page table lock
already protects the race for parallel freeing.

Please do not use mmap_sem write-side lock which is well known
contented lock.

Cc: Todd Kjos <tkjos@google.com>
Cc: Martijn Coenen <maco@android.com>
Cc: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-19 14:50:11 +01:00
Todd Kjos 26528be672 binder: fix handling of misaligned binder object
Fixes crash found by syzbot:
kernel BUG at drivers/android/binder_alloc.c:LINE! (2)

Reported-and-tested-by: syzbot+55de1eb4975dec156d8f@syzkaller.appspotmail.com
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15 08:49:20 +01:00
Todd Kjos 36f3093792 binder: fix sparse issue in binder_alloc_selftest.c
Fixes sparse issues reported by the kbuild test robot running
on https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
char-misc-testing: bde4a19fc0 ("binder: use userspace pointer as base
of buffer space")

Error output (drivers/android/binder_alloc_selftest.c):
sparse: warning: incorrect type in assignment (different address spaces)
sparse:    expected void *page_addr
sparse:    got void [noderef] <asn:1> *user_data
sparse: error: subtraction of different types can't work

Fixed by adding necessary "__user" tags.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-14 08:13:56 +01:00
Todd Kjos bde4a19fc0 binder: use userspace pointer as base of buffer space
Now that alloc->buffer points to the userspace vm_area
rename buffer->data to buffer->user_data and rename
local pointers that hold user addresses. Also use the
"__user" tag to annotate all user pointers so sparse
can flag cases where user pointer vaues  are copied to
kernel pointers. Refactor code to use offsets instead
of user pointers.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:43:57 +01:00
Todd Kjos c41358a5f5 binder: remove user_buffer_offset
Remove user_buffer_offset since there is no kernel
buffer pointer anymore.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:43:57 +01:00
Todd Kjos 880211667b binder: remove kernel vm_area for buffer space
Remove the kernel's vm_area and the code that maps
buffer pages into it.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:43:57 +01:00
Todd Kjos db6b0b810b binder: avoid kernel vm_area for buffer fixups
Refactor the functions to validate and fixup struct
binder_buffer pointer objects to avoid using vm_area
pointers. Instead copy to/from kernel space using
binder_alloc_copy_to_buffer() and
binder_alloc_copy_from_buffer(). The following
functions were refactored:

	refactor binder_validate_ptr()
	binder_validate_fixup()
	binder_fixup_parent()

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:43:57 +01:00
Todd Kjos 7a67a39320 binder: add function to copy binder object from buffer
When creating or tearing down a transaction, the binder driver
examines objects in the buffer and takes appropriate action.
To do this without needing to dereference pointers into the
buffer, the local copies of the objects are needed. This patch
introduces a function to validate and copy binder objects
from the buffer to a local structure.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:43:57 +01:00
Todd Kjos 8ced0c6231 binder: add functions to copy to/from binder buffers
Avoid vm_area when copying to or from binder buffers.
Instead, new copy functions are added that copy from
kernel space to binder buffer space. These use
kmap_atomic() and kunmap_atomic() to create temporary
mappings and then memcpy() is used to copy within
that page.

Also, kmap_atomic() / kunmap_atomic() use the appropriate
cache flushing to support VIVT cache architectures.
Allow binder to build if CPU_CACHE_VIVT is defined.

Several uses of the new functions are added here. More
to follow in subsequent patches.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:43:57 +01:00
Todd Kjos 1a7c3d9bb7 binder: create userspace-to-binder-buffer copy function
The binder driver uses a vm_area to map the per-process
binder buffer space. For 32-bit android devices, this is
now taking too much vmalloc space. This patch removes
the use of vm_area when copying the transaction data
from the sender to the buffer space. Instead of using
copy_from_user() for multi-page copies, it now uses
binder_alloc_copy_user_to_buffer() which uses kmap()
and kunmap() to map each page, and uses copy_from_user()
for copying to that page.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12 10:43:57 +01:00
Greg Kroah-Hartman 5c07488d99 Merge 5.0-rc6 into char-misc-next
We need the char-misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-11 09:05:58 +01:00