binder_poll() passes the thread->wait waitqueue that
can be slept on for work. When a thread that uses
epoll explicitly exits using BINDER_THREAD_EXIT,
the waitqueue is freed, but it is never removed
from the corresponding epoll data structure. When
the process subsequently exits, the epoll cleanup
code tries to access the waitlist, which results in
a use-after-free.
Prevent this by using POLLFREE when the thread exits.
Signed-off-by: Martijn Coenen <maco@android.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
proc->files cleanup is initiated by binder_vma_close. Therefore
a reference on the binder_proc is not enough to prevent the
files_struct from being released while the binder_proc still has
a reference. This can lead to an attempt to dereference the
stale pointer obtained from proc->files prior to proc->files
cleanup. This has been seen once in task_get_unused_fd_flags()
when __alloc_fd() is called with a stale "files".
The fix is to protect proc->files with a mutex to prevent cleanup
while in use.
Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a call to put_user() fails, we failed to
properly free a transaction and send a failed
reply (if necessary).
Signed-off-by: Martijn Coenen <maco@android.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This flag determines whether the thread should currently
process the work in the thread->todo worklist.
The prime usecase for this is improving the performance
of synchronous transactions: all synchronous transactions
post a BR_TRANSACTION_COMPLETE to the calling thread,
but there's no reason to return that command to userspace
right away - userspace anyway needs to wait for the reply.
Likewise, a synchronous transaction that contains a binder
object can cause a BC_ACQUIRE/BC_INCREFS to be returned to
userspace; since the caller must anyway hold a strong/weak
ref for the duration of the call, postponing these commands
until the reply comes in is not a problem.
Note that this flag is not used to determine whether a
thread can handle process work; a thread should never pick
up process work when thread work is still pending.
Before patch:
------------------------------------------------------------------
Benchmark Time CPU Iterations
------------------------------------------------------------------
BM_sendVec_binderize/4 45959 ns 20288 ns 34351
BM_sendVec_binderize/8 45603 ns 20080 ns 34909
BM_sendVec_binderize/16 45528 ns 20113 ns 34863
BM_sendVec_binderize/32 45551 ns 20122 ns 34881
BM_sendVec_binderize/64 45701 ns 20183 ns 34864
BM_sendVec_binderize/128 45824 ns 20250 ns 34576
BM_sendVec_binderize/256 45695 ns 20171 ns 34759
BM_sendVec_binderize/512 45743 ns 20211 ns 34489
BM_sendVec_binderize/1024 46169 ns 20430 ns 34081
After patch:
------------------------------------------------------------------
Benchmark Time CPU Iterations
------------------------------------------------------------------
BM_sendVec_binderize/4 42939 ns 17262 ns 40653
BM_sendVec_binderize/8 42823 ns 17243 ns 40671
BM_sendVec_binderize/16 42898 ns 17243 ns 40594
BM_sendVec_binderize/32 42838 ns 17267 ns 40527
BM_sendVec_binderize/64 42854 ns 17249 ns 40379
BM_sendVec_binderize/128 42881 ns 17288 ns 40427
BM_sendVec_binderize/256 42917 ns 17297 ns 40429
BM_sendVec_binderize/512 43184 ns 17395 ns 40411
BM_sendVec_binderize/1024 43119 ns 17357 ns 40432
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull char/misc updates from Greg KH:
"Here is the big set of char/misc and other driver subsystem patches
for 4.15-rc1.
There are small changes all over here, hyperv driver updates, pcmcia
driver updates, w1 driver updats, vme driver updates, nvmem driver
updates, and lots of other little one-off driver updates as well. The
shortlog has the full details.
All of these have been in linux-next for quite a while with no
reported issues"
* tag 'char-misc-4.15-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (90 commits)
VME: Return -EBUSY when DMA list in use
w1: keep balance of mutex locks and refcnts
MAINTAINERS: Update VME subsystem tree.
nvmem: sunxi-sid: add support for A64/H5's SID controller
nvmem: imx-ocotp: Update module description
nvmem: imx-ocotp: Enable i.MX7D OTP write support
nvmem: imx-ocotp: Add i.MX7D timing write clock setup support
nvmem: imx-ocotp: Move i.MX6 write clock setup to dedicated function
nvmem: imx-ocotp: Add support for banked OTP addressing
nvmem: imx-ocotp: Pass parameters via a struct
nvmem: imx-ocotp: Restrict OTP write to IMX6 processors
nvmem: uniphier: add UniPhier eFuse driver
dt-bindings: nvmem: add description for UniPhier eFuse
nvmem: set nvmem->owner to nvmem->dev->driver->owner if unset
nvmem: qfprom: fix different address space warnings of sparse
nvmem: mtk-efuse: fix different address space warnings of sparse
nvmem: mtk-efuse: use stack for nvmem_config instead of malloc'ing it
nvmem: imx-iim: use stack for nvmem_config instead of malloc'ing it
thunderbolt: tb: fix use after free in tb_activate_pcie_devices
MAINTAINERS: Add git tree for Thunderbolt development
...
Pull module updates from Jessica Yu:
"Summary of modules changes for the 4.15 merge window:
- treewide module_param_call() cleanup, fix up set/get function
prototype mismatches, from Kees Cook
- minor code cleanups"
* tag 'modules-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: Do not paper over type mismatches in module_param_call()
treewide: Fix function prototypes for module_param_call()
module: Prepare to convert all module_param_call() prototypes
kernel/module: Delete an error message for a failed memory allocation in add_module_usage()
Several function prototypes for the set/get functions defined by
module_param_call() have a slightly wrong argument types. This fixes
those in an effort to clean up the calls when running under type-enforced
compiler instrumentation for CFI. This is the result of running the
following semantic patch:
@match_module_param_call_function@
declarer name module_param_call;
identifier _name, _set_func, _get_func;
expression _arg, _mode;
@@
module_param_call(_name, _set_func, _get_func, _arg, _mode);
@fix_set_prototype
depends on match_module_param_call_function@
identifier match_module_param_call_function._set_func;
identifier _val, _param;
type _val_type, _param_type;
@@
int _set_func(
-_val_type _val
+const char * _val
,
-_param_type _param
+const struct kernel_param * _param
) { ... }
@fix_get_prototype
depends on match_module_param_call_function@
identifier match_module_param_call_function._get_func;
identifier _val, _param;
type _val_type, _param_type;
@@
int _get_func(
-_val_type _val
+char * _val
,
-_param_type _param
+const struct kernel_param * _param
) { ... }
Two additional by-hand changes are included for places where the above
Coccinelle script didn't notice them:
drivers/platform/x86/thinkpad_acpi.c
fs/lockd/svc.c
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
We want the driver fixes in here and this resolves a merge issue with
the binder driver.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pr_err() messages should terminated with a new-line to avoid
other messages being concatenated onto the end.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because we're not guaranteed that subsequent calls
to poll() will have a poll_table_struct parameter
with _qproc set. When _qproc is not set, poll_wait()
is a noop, and we won't be woken up correctly.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
User-space normally keeps the node alive when creating a transaction
since it has a reference to the target. The local strong ref keeps it
alive if the sending process dies before the target process processes
the transaction. If the source process is malicious or has a reference
counting bug, this can fail.
In this case, when we attempt to decrement the node in the failure
path, the node has already been freed.
This is fixed by taking a tmpref on the node while constructing
the transaction. To avoid re-acquiring the node lock and inner
proc lock to increment the proc's tmpref, a helper is used that
does the ref increments on both the node and proc.
Signed-off-by: Todd Kjos <tkjos@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7a4408c6bd ("binder: make sure accesses to proc/thread are
safe") made a change to enqueue tcomplete to thread->todo before
enqueuing the transaction. However, in err_dead_proc_or_thread case,
the tcomplete is directly freed, without dequeued. It may cause the
thread->todo list to be corrupted.
So, dequeue it before freeing.
Fixes: 7a4408c6bd ("binder: make sure accesses to proc/thread are safe")
Signed-off-by: Xu YiPing <xuyiping@hisilicon.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 372e3147df ("binder: guarantee txn complete / errors delivered
in-order") incorrectly defined a local ret value. This ret value will
be invalid when out of the if block
Fixes: 372e3147df ("binder: refactor binder ref inc/dec for thread safety")
Signed-off-by: Xu YiPing <xuyiping@hislicon.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allowing binder to expose the 64-bit API on 32-bit kernels caused a
build warning:
drivers/android/binder.c: In function 'binder_transaction_buffer_release':
drivers/android/binder.c:2220:15: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
fd_array = (u32 *)(parent_buffer + fda->parent_offset);
^
drivers/android/binder.c: In function 'binder_translate_fd_array':
drivers/android/binder.c:2445:13: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
fd_array = (u32 *)(parent_buffer + fda->parent_offset);
^
drivers/android/binder.c: In function 'binder_fixup_parent':
drivers/android/binder.c:2511:18: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
This adds extra type casts to avoid the warning.
However, there is another problem with the Kconfig option: turning
it on or off creates two incompatible ABI versions, a kernel that
has this enabled cannot run user space that was built without it
or vice versa. A better solution might be to leave the option hidden
until the binder code is fixed to deal with both ABI versions.
Fixes: e8d2ed7db7 ("Revert "staging: Fix build issues with new binder API"")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This can cause issues with processes using the poll()
interface:
1) client sends two oneway transactions
2) the second one gets queued on async_todo
(because the server didn't handle the first one
yet)
3) server returns from poll(), picks up the
first transaction and does transaction work
4) server is done with the transaction, sends
BC_FREE_BUFFER, and the second transaction gets
moved to thread->todo
5) libbinder's handlePolledCommands() only handles
the commands in the current data buffer, so
doesn't see the new transaction
6) the server continues running and issues a new
outgoing transaction. Now, it suddenly finds
the incoming oneway transaction on its thread
todo, and returns that to userspace.
7) userspace does not expect this to happen; it
may be holding a lock while making the outgoing
transaction, and if handling the incoming
trasnaction requires taking the same lock,
userspace will deadlock.
By queueing the async transaction to the proc
workqueue, we make sure it's only picked up when
a thread is ready for proc work.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This allows userspace to request death notifications without
having to worry about getting an immediate callback on the same
thread; one scenario where this would be problematic is if the
death recipient handler grabs a lock that was already taken
earlier (eg as part of a nested transaction).
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because is_spin_locked() always returns false on UP
systems.
Use assert_spin_locked() instead, and remove the
WARN_ON() instances, since those were easy to verify.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The BINDER_GET_NODE_DEBUG_INFO ioctl will return debug info on
a node. Each successive call reusing the previous return value
will return the next node. The data will be used by
libmemunreachable to mark the pointers with kernel references
as reachable.
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of pushing new transactions to the process
waitqueue, select a thread that is waiting on proc
work to handle the transaction. This will make it
easier to improve priority inheritance in future
patches, by setting the priority before we wake up
a thread.
If we can't find a waiting thread, submit the work
to the proc waitqueue instead as we did previously.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Removes the process waitqueue, so that threads
can only wait on the thread waitqueue. Whenever
there is process work to do, pick a thread and
wake it up. Having the caller pick a thread is
helpful for things like priority inheritance.
This also fixes an issue with using epoll(),
since we no longer have to block on different
waitqueues.
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Martijn Coenen
Elad Wexler
Greg Kroah-Hartman
Tetsuo Handa
Todd Kjos
Al Viro
Linus Torvalds
Kees Cook
Arvind Yadav
Xu YiPing
Arnd Bergmann
Colin Cross