linux.git/drivers/android, branch v5.16.1

binder: fix async_free_space accounting for empty parcels

2021-12-21T10:07:34+00:00

In 4.13, commit 74310e06be4d ("android: binder: Move buffer out of area shared with user space")
fixed a kernel structure visibility issue. As part of that patch,
sizeof(void *) was used as the buffer size for 0-length data payloads so
the driver could detect abusive clients sending 0-length asynchronous
transactions to a server by enforcing limits on async_free_size.

Unfortunately, on the "free" side, the accounting of async_free_space
did not add the sizeof(void *) back. The result was that up to 8-bytes of
async_free_space were leaked on every async transaction of 8-bytes or
less.  These small transactions are uncommon, so this accounting issue
has gone undetected for several years.

The fix is to use "buffer_size" (the allocated buffer size) instead of
"size" (the logical buffer size) when updating the async_free_space
during the free operation. These are the same except for this
corner case of asynchronous transactions with payloads < 8 bytes.

Fixes: 74310e06be4d ("android: binder: Move buffer out of area shared with user space")
Signed-off-by: Todd Kjos 
Cc: stable@vger.kernel.org # 4.14+
Link: https://lore.kernel.org/r/20211220190150.2107077-1-tkjos@google.com
Signed-off-by: Greg Kroah-Hartman

binder: use wake_up_pollfree()

2021-12-09T18:49:56+00:00

wake_up_poll() uses nr_exclusive=1, so it's not guaranteed to wake up
all exclusive waiters.  Yet, POLLFREE *must* wake up all waiters.  epoll
and aio poll are fortunately not affected by this, but it's very
fragile.  Thus, the new function wake_up_pollfree() has been introduced.

Convert binder to use wake_up_pollfree().

Reported-by: Linus Torvalds 
Fixes: f5cb779ba163 ("ANDROID: binder: remove waitqueue when thread exits.")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211209010455.42744-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers

binder: fix test regression due to sender_euid change

2021-11-17T15:08:52+00:00

This is a partial revert of commit
29bc22ac5e5b ("binder: use euid from cred instead of using task").
Setting sender_euid using proc->cred caused some Android system test
regressions that need further investigation. It is a partial
reversion because subsequent patches rely on proc->cred.

Fixes: 29bc22ac5e5b ("binder: use euid from cred instead of using task")
Cc: stable@vger.kernel.org # 4.4+
Acked-by: Christian Brauner 
Signed-off-by: Todd Kjos 
Change-Id: I9b1769a3510fed250bb21859ef8beebabe034c66
Link: https://lore.kernel.org/r/20211112180720.2858135-1-tkjos@google.com
Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2021-11-04T15:21:47+00:00

Pull char/misc driver updates from Greg KH:
 "Here is the big set of char and misc and other tiny driver subsystem
  updates for 5.16-rc1.

  Loads of things in here, all of which have been in linux-next for a
  while with no reported problems (except for one called out below.)

  Included are:

   - habanana labs driver updates, including dma_buf usage, reviewed and
     acked by the dma_buf maintainers

   - iio driver update (going through this tree not staging as they
     really do not belong going through that tree anymore)

   - counter driver updates

   - hwmon driver updates that the counter drivers needed, acked by the
     hwmon maintainer

   - xillybus driver updates

   - binder driver updates

   - extcon driver updates

   - dma_buf module namespaces added (will cause a build error in arm64
     for allmodconfig, but that change is on its way through the drm
     tree)

   - lkdtm driver updates

   - pvpanic driver updates

   - phy driver updates

   - virt acrn and nitr_enclaves driver updates

   - smaller char and misc driver updates"

* tag 'char-misc-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (386 commits)
  comedi: dt9812: fix DMA buffers on stack
  comedi: ni_usb6501: fix NULL-deref in command paths
  arm64: errata: Enable TRBE workaround for write to out-of-range address
  arm64: errata: Enable workaround for TRBE overwrite in FILL mode
  coresight: trbe: Work around write to out of range
  coresight: trbe: Make sure we have enough space
  coresight: trbe: Add a helper to determine the minimum buffer size
  coresight: trbe: Workaround TRBE errata overwrite in FILL mode
  coresight: trbe: Add infrastructure for Errata handling
  coresight: trbe: Allow driver to choose a different alignment
  coresight: trbe: Decouple buffer base from the hardware base
  coresight: trbe: Add a helper to pad a given buffer area
  coresight: trbe: Add a helper to calculate the trace generated
  coresight: trbe: Defer the probe on offline CPUs
  coresight: trbe: Fix incorrect access of the sink specific data
  coresight: etm4x: Add ETM PID for Kryo-5XX
  coresight: trbe: Prohibit trace before disabling TRBE
  coresight: trbe: End the AUX handle on truncation
  coresight: trbe: Do not truncate buffer on IRQ
  coresight: trbe: Fix handling of spurious interrupts
  ...

Merge tag 'selinux-pr-20211101' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

2021-11-02T04:06:18+00:00

Pull selinux updates from Paul Moore:

 - Add LSM/SELinux/Smack controls and auditing for io-uring.

   As usual, the individual commit descriptions have more detail, but we
   were basically missing two things which we're adding here:

      + establishment of a proper audit context so that auditing of
        io-uring ops works similarly to how it does for syscalls (with
        some io-uring additions because io-uring ops are *not* syscalls)

      + additional LSM hooks to enable access control points for some of
        the more unusual io-uring features, e.g. credential overrides.

   The additional audit callouts and LSM hooks were done in conjunction
   with the io-uring folks, based on conversations and RFC patches
   earlier in the year.

 - Fixup the binder credential handling so that the proper credentials
   are used in the LSM hooks; the commit description and the code
   comment which is removed in these patches are helpful to understand
   the background and why this is the proper fix.

 - Enable SELinux genfscon policy support for securityfs, allowing
   improved SELinux filesystem labeling for other subsystems which make
   use of securityfs, e.g. IMA.

* tag 'selinux-pr-20211101' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  security: Return xattr name from security_dentry_init_security()
  selinux: fix a sock regression in selinux_ip_postroute_compat()
  binder: use cred instead of task for getsecid
  binder: use cred instead of task for selinux checks
  binder: use euid from cred instead of using task
  LSM: Avoid warnings about potentially unused hook variables
  selinux: fix all of the W=1 build warnings
  selinux: make better use of the nf_hook_state passed to the NF hooks
  selinux: fix race condition when computing ocontext SIDs
  selinux: remove unneeded ipv6 hook wrappers
  selinux: remove the SELinux lockdown implementation
  selinux: enable genfscon labeling for securityfs
  Smack: Brutalist io_uring support
  selinux: add support for the io_uring access controls
  lsm,io_uring: add LSM hooks to io_uring
  io_uring: convert io_uring to the secure anon inode interface
  fs: add anon_inode_getfile_secure() similar to anon_inode_getfd_secure()
  audit: add filtering for io_uring records
  audit,io_uring,io-wq: add some basic audit support to io_uring
  audit: prepare audit_context for use in calling contexts beyond syscalls

binder: don't detect sender/target during buffer cleanup

2021-10-19T07:38:55+00:00

When freeing txn buffers, binder_transaction_buffer_release()
attempts to detect whether the current context is the target by
comparing current->group_leader to proc->tsk. This is an unreliable
test. Instead explicitly pass an 'is_failure' boolean.

Detecting the sender was being used as a way to tell if the
transaction failed to be sent.  When cleaning up after
failing to send a transaction, there is no need to close
the fds associated with a BINDER_TYPE_FDA object. Now
'is_failure' can be used to accurately detect this case.

Fixes: 44d8047f1d87 ("binder: use standard functions to allocate fds")
Cc: stable 
Acked-by: Christian Brauner 
Signed-off-by: Todd Kjos 
Link: https://lore.kernel.org/r/20211015233811.3532235-1-tkjos@google.com
Signed-off-by: Greg Kroah-Hartman

binder: use cred instead of task for getsecid

2021-10-15T00:48:43+00:00

Use the 'struct cred' saved at binder_open() to lookup
the security ID via security_cred_getsecid(). This
ensures that the security context that opened binder
is the one used to generate the secctx.

Cc: stable@vger.kernel.org # 5.4+
Fixes: ec74136ded79 ("binder: create node flag to request sender's security context")
Signed-off-by: Todd Kjos 
Suggested-by: Stephen Smalley 
Reported-by: kernel test robot 
Acked-by: Casey Schaufler 
Signed-off-by: Paul Moore

binder: use cred instead of task for selinux checks

2021-10-15T00:48:04+00:00

Since binder was integrated with selinux, it has passed
'struct task_struct' associated with the binder_proc
to represent the source and target of transactions.
The conversion of task to SID was then done in the hook
implementations. It turns out that there are race conditions
which can result in an incorrect security context being used.

Fix by using the 'struct cred' saved during binder_open and pass
it to the selinux subsystem.

Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables)
Fixes: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.")
Suggested-by: Jann Horn 
Signed-off-by: Todd Kjos 
Acked-by: Casey Schaufler 
Signed-off-by: Paul Moore

binder: use euid from cred instead of using task

2021-10-14T21:19:40+00:00

Save the 'struct cred' associated with a binder process
at initial open to avoid potential race conditions
when converting to an euid.

Set a transaction's sender_euid from the 'struct cred'
saved at binder_open() instead of looking up the euid
from the binder proc's 'struct task'. This ensures
the euid is associated with the security context that
of the task that opened binder.

Cc: stable@vger.kernel.org # 4.4+
Fixes: 457b9a6f09f0 ("Staging: android: add binder driver")
Signed-off-by: Todd Kjos 
Suggested-by: Stephen Smalley 
Suggested-by: Jann Horn 
Acked-by: Casey Schaufler 
Signed-off-by: Paul Moore

binder: make sure fd closes complete

2021-09-14T07:02:13+00:00

During BC_FREE_BUFFER processing, the BINDER_TYPE_FDA object
cleanup may close 1 or more fds. The close operations are
completed using the task work mechanism -- which means the thread
needs to return to userspace or the file object may never be
dereferenced -- which can lead to hung processes.

Force the binder thread back to userspace if an fd is closed during
BC_FREE_BUFFER handling.

Fixes: 80cd795630d6 ("binder: fix use-after-free due to ksys_close() during fdget()")
Cc: stable 
Reviewed-by: Martijn Coenen 
Acked-by: Christian Brauner 
Signed-off-by: Todd Kjos 
Link: https://lore.kernel.org/r/20210830195146.587206-1-tkjos@google.com
Signed-off-by: Greg Kroah-Hartman