linux-stable.git/drivers/android, branch v5.19.2

android: binder: stop saving a pointer to the VMA

2022-08-17T13:15:40+00:00

[ Upstream commit a43cfc87caaf46710c8027a8c23b8a55f1078f19 ]

Do not record a pointer to a VMA outside of the mmap_lock for later use.
This is unsafe and there are a number of failure paths *after* the
recorded VMA pointer may be freed during setup.  There is no callback to
the driver to clear the saved pointer from generic mm code.  Furthermore,
the VMA pointer may become stale if any number of VMA operations end up
freeing the VMA so saving it was fragile to being with.

Instead, change the binder_alloc struct to record the start address of the
VMA and use vma_lookup() to get the vma when needed.  Add lockdep
mmap_lock checks on updates to the vma pointer to ensure the lock is held
and depend on that lock for synchronization of readers and writers - which
was already the case anyways, so the smp_wmb()/smp_rmb() was not
necessary.

[akpm@linux-foundation.org: fix drivers/android/binder_alloc_selftest.c]
Link: https://lkml.kernel.org/r/20220621140212.vpkio64idahetbyf@revolver
Fixes: da1b9564e85b ("android: binder: fix the race mmap and alloc_new_buf_locked")
Reported-by: syzbot+58b51ac2b04e388ab7b0@syzkaller.appspotmail.com
Signed-off-by: Liam R. Howlett 
Cc: Minchan Kim 
Cc: Christian Brauner (Microsoft) 
Cc: Greg Kroah-Hartman 
Cc: Hridya Valsaraju 
Cc: Joel Fernandes 
Cc: Martijn Coenen 
Cc: Suren Baghdasaryan 
Cc: Todd Kjos 
Cc: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

binder: fix redefinition of seq_file attributes

2022-08-17T13:15:29+00:00

[ Upstream commit b7e241bbff24f9e106bf616408fd58bcedc44bae ]

The patchset in [1] exported some definitions to binder_internal.h in
order to make the debugfs entries such as 'stats' and 'transaction_log'
available in a binderfs instance. However, the DEFINE_SHOW_ATTRIBUTE
macro expands into a static function/variable pair, which in turn get
redefined each time a source file includes this internal header.

This problem was made evident after a report from the kernel test robot
 where several W=1 build warnings are seen in downstream
kernels. See the following example:

  include/../drivers/android/binder_internal.h:111:23: warning: 'binder_stats_fops' defined but not used [-Wunused-const-variable=]
     111 | DEFINE_SHOW_ATTRIBUTE(binder_stats);
         |                       ^~~~~~~~~~~~
  include/linux/seq_file.h:174:37: note: in definition of macro 'DEFINE_SHOW_ATTRIBUTE'
     174 | static const struct file_operations __name ## _fops = {                 \
         |                                     ^~~~~~

This patch fixes the above issues by moving back the definitions into
binder.c and instead creates an array of the debugfs entries which is
more convenient to share with binderfs and iterate through.

  [1] https://lore.kernel.org/all/20190903161655.107408-1-hridya@google.com/

Fixes: 0e13e452dafc ("binder: Add stats, state and transactions files")
Fixes: 03e2e07e3814 ("binder: Make transaction_log available in binderfs")
Reported-by: kernel test robot 
Signed-off-by: Carlos Llamas 
Link: https://lore.kernel.org/r/20220701182041.2134313-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

Merge tag 'pull-work.fd-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-06-06T00:14:03+00:00

Pull file descriptor fix from Al Viro:
 "Fix for breakage in #work.fd this window"

* tag 'pull-work.fd-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix the breakage in close_fd_get_file() calling conventions change

fix the breakage in close_fd_get_file() calling conventions change

2022-06-05T19:03:03+00:00

It used to grab an extra reference to struct file rather than
just transferring to caller the one it had removed from descriptor
table.  New variant doesn't, and callers need to be adjusted.

Reported-and-tested-by: syzbot+47dd250f527cb7bebf24@syzkaller.appspotmail.com
Fixes: 6319194ec57b ("Unify the primitives for file descriptor closing")
Signed-off-by: Al Viro

Merge tag 'pull-18-rc1-work.fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-06-05T01:52:00+00:00

Pull file descriptor updates from Al Viro.

 - Descriptor handling cleanups

* tag 'pull-18-rc1-work.fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Unify the primitives for file descriptor closing
  fs: remove fget_many and fput_many interface
  io_uring_enter(): don't leave f.flags uninitialized

binder: fix atomic sleep when get extended error

2022-05-19T16:41:33+00:00

binder_inner_proc_lock(thread->proc) is a spin lock, copy_to_user can't
be called with in this lock.

Copy it as a local variable to fix it.

Fixes: bd32889e841c ("binder: add BINDER_GET_EXTENDED_ERROR ioctl")
Reported-by: syzbot+46fff6434a7f968ecb39@syzkaller.appspotmail.com
Reviewed-by: Carlos Llamas 
Signed-off-by: Schspa Shi 
Link: https://lore.kernel.org/r/20220518011754.49348-1-schspa@gmail.com
Signed-off-by: Greg Kroah-Hartman

binder: fix potential UAF of target_{proc,thread}

2022-05-19T16:41:26+00:00

Commit 9474be34a727 ("binder: add failed transaction logging info")
dereferences target_{proc,thread} after they have been potentially
freed by binder_proc_dec_tmpref() and binder_thread_dec_tmpref().

This patch delays the release of the two references after their last
usage. Fixes the following two errors reported by smatch:

  drivers/android/binder.c:3562 binder_transaction() error: dereferencing freed memory 'target_proc'
  drivers/android/binder.c:3563 binder_transaction() error: dereferencing freed memory 'target_thread'

Fixes: 9474be34a727 ("binder: add failed transaction logging info")
Reported-by: Dan Carpenter 
Acked-by: Todd Kjos 
Signed-off-by: Carlos Llamas 
Link: https://lore.kernel.org/r/20220517185817.598872-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman

binder: fix printk format for commands

2022-05-19T16:41:11+00:00

Make sure we use unsigned format specifier %u for binder commands as
most of them are encoded above INT_MAX. This prevents negative values
when logging them as in the following case:

[  211.895781] binder: 8668:8668 BR_REPLY 258949 0:0, cmd -2143260157 size 0-0 ptr 0000006e766a8000-0000006e766a8000

Acked-by: Todd Kjos 
Acked-by: Christian Brauner (Microsoft) 
Signed-off-by: Carlos Llamas 
Link: https://lore.kernel.org/r/20220509231901.3852573-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman

Unify the primitives for file descriptor closing

2022-05-14T22:49:01+00:00

Currently we have 3 primitives for removing an opened file from descriptor
table - pick_file(), __close_fd_get_file() and close_fd_get_file().  Their
calling conventions are rather odd and there's a code duplication for no
good reason.  They can be unified -

1) have __range_close() cap max_fd in the very beginning; that way
we don't need separate way for pick_file() to report being past the end
of descriptor table.

2) make {__,}close_fd_get_file() return file (or NULL) directly, rather
than returning it via struct file ** argument.  Don't bother with
(bogus) return value - nobody wants that -ENOENT.

3) make pick_file() return NULL on unopened descriptor - the only caller
that used to care about the distinction between descriptor past the end
of descriptor table and finding NULL in descriptor table doesn't give
a damn after (1).

4) lift ->files_lock out of pick_file()

That actually simplifies the callers, as well as the primitives themselves.
Code duplication is also gone...

Reviewed-by: Christian Brauner (Microsoft) 
Signed-off-by: Al Viro

binder: additional transaction error logs

2022-05-09T13:43:24+00:00

Log readable and specific error messages whenever a transaction failure
happens. This will ensure better context is given to regular users about
these unique error cases, without having to decode a cryptic log.

Acked-by: Todd Kjos 
Acked-by: Christian Brauner (Microsoft) 
Signed-off-by: Carlos Llamas 
Link: https://lore.kernel.org/r/20220429235644.697372-6-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman