This reverts commit 336fd4f5f2.
Please note that `strlcpy()` does *NOT* do what you think it does.
strlcpy() *ALWAYS* reads the full input string, regardless of the
'length' parameter. That is, if the input is not zero-terminated,
strlcpy() will *READ* beyond input boundaries. It does this, because it
always returns the size it *would* copy if the target was big enough,
not the truncated size it actually copied.
The original code was perfectly fine. The hid device is
zero-initialized and the strncpy() functions copied up to n-1
characters. The result is always zero-terminated this way.
This is the third time someone tried to replace strncpy with strlcpy in
this function, and gets it wrong. I now added a comment that should at
least make people reconsider.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
When a UHID_CREATE command is written to the uhid char device, a
copy_from_user() is done from a user pointer embedded in the command.
When the address limit is KERNEL_DS, e.g. as is the case during
sys_sendfile(), this can read from kernel memory. Alternatively,
information can be leaked from a setuid binary that is tricked to write
to the file descriptor. Therefore, forbid UHID_CREATE in these cases.
No other commands in uhid_char_write() are affected by this bug and
UHID_CREATE is marked as "obsolete", so apply the restriction to
UHID_CREATE only rather than to uhid_char_write() entirely.
Thanks to Dmitry Vyukov for adding uhid definitions to syzkaller and to
Jann Horn for commit 9da3f2b740 ("x86/fault: BUG() when uaccess
helpers fault on kernel addresses"), allowing this bug to be found.
Reported-by: syzbot+72473edc9bf4eb1c6556@syzkaller.appspotmail.com
Fixes: d365c6cfd3 ("HID: uhid: add UHID_CREATE and UHID_DESTROY events")
Cc: <stable@vger.kernel.org> # v3.6+
Cc: Jann Horn <jannh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Pull HID updates from Jiri Kosina:
- 3rd generation Wacom Intuos BT device support from Aaron Armstrong
Skomra
- support for NSG-MR5U and NSG-MR7U devices from Todd Kelner
- multitouch Razer Blade Stealth support from Benjamin Tissoires
- Elantech touchpad support from Alexandrov Stansilav
- a few other scattered-around fixes and cleanups to drivers and
generic code
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (31 commits)
HID: google: Enable PM Full On mode when adjusting backlight
HID: google: add google hammer HID driver
HID: core: reset the quirks before calling probe again
HID: multitouch: do not set HID_QUIRK_NO_INIT_REPORTS
HID: core: remove the need for HID_QUIRK_NO_EMPTY_INPUT
HID: use BIT() macro for quirks too
HID: use BIT macro instead of plain integers for flags
HID: multitouch: remove dead zones of Razer Blade Stealth
HID: multitouch: export a quirk for the button handling of touchpads
HID: usbhid: extend the polling interval configuration to keyboards
HID: ntrig: document sysfs interface
HID: wacom: wacom_wac_collection() is local to wacom_wac.c
HID: wacom: generic: add the "Report Valid" usage
HID: wacom: generic: Support multiple tools per report
HID: wacom: Add support for 3rd generation Intuos BT
HID: core: rewrite the hid-generic automatic unbind
HID: sony: Add touchpad support for NSG-MR5U and NSG-MR7U remotes
HID: hid-multitouch: Use true and false for boolean values
HID: hid-ntrig: use true and false for boolean values
HID: logitech-hidpp: document sysfs interface
...
gcc-8 reports
drivers/hid/uhid.c: In function 'uhid_dev_create2':
./include/linux/string.h:245:9: warning: '__builtin_strncpy' output may
be truncated copying 127 bytes from a string of length 127
[-Wstringop-truncation]
The compiler require that the input param 'len' of strncpy() should be
greater than the length of the src string, so that '\0' is copied as
well. We can just use strlcpy() to avoid this warning.
Signed-off-by: Xiongfeng Wang <xiongfeng.wang@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Although HID itself is transport-agnostic, occasionally a driver may
want to interact with the low-level transport that a device is connected
through. To do this, we need to know what kind of bus is in use. The
first guess may be to look at the 'bus' field of the 'struct hid_device',
but this field may be emulated in some cases (e.g. uhid).
More ideally, we can check which ll_driver a device is using. This
function introduces a 'hid_is_using_ll_driver' function and makes the
'struct hid_ll_driver' of the four most common transports accessible
through hid.h.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Acked-By: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Many modules call misc_register and misc_deregister in its module init
and exit methods without any additional code. This ends up being
boilerplate. This patch adds helper macro module_misc_device(), that
replaces module_init()/ module_exit() with template functions.
This patch also converts drivers to use new macro.
Change since v1:
Add device.h include in miscdevice.h as module_driver macro was not
available from other include files in some architectures.
Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many devices use userspace bluetooth stacks like BlueZ or Bluedroid in combination
with uhid. If any of these stacks is used with a HID device for which the driver
performs a HID request as part .probe (or technically another HID operation),
this results in a deadlock situation. The deadlock results in a 5 second timeout
for I/O operations in HID drivers, so isn't fatal, but none of the I/O operations
have a chance of succeeding.
The root cause for the problem is that uhid only allows for one request to be
processed at a time per uhid instance and locks out other operations. This means
that if a user space is creating a new HID device through 'UHID_CREATE', which
ultimately triggers '.probe' through the HID layer. Then any HID request e.g. a
read for calibration data would trigger a HID operation on uhid again, but it
won't go out to userspace, because it is still stuck in UHID_CREATE.
In addition bluetooth stacks are typically single threaded, so they wouldn't be
able to handle any requests while waiting on uhid.
Lucikly the UHID spec is somewhat flexible and allows for fixing the issue,
without breaking user space. The idea which the patch implements as discussed
with David Herrmann is to decouple adding of a hid device (which triggers .probe)
from UHID_CREATE. The work will kick off roughly once UHID_CREATE completed (or
else will wait a tiny bit of time in .probe for a lock). A HID driver has to call
HID to call 'hid_hw_start()' as part of .probe once it is ready for I/O, which
triggers UHID_START to user space. Any HID operations should function now within
.probe and won't deadlock because userspace is stuck on UHID_CREATE.
We verified this patch on Bluedroid with Android 6.0 and on desktop Linux with
BlueZ stacks. Prior to the patch they had the deadlock issue.
[jkosina@suse.cz: reword subject]
Signed-off-by: Roderick Colenbrander <roderick.colenbrander@sony.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
When uhid_get_report() or uhid_set_report() are called, they emit on the
char device a UHID_GET_REPORT or UHID_SET_REPORT message. Then, the
protocol says that the user space asnwers with UHID_GET_REPORT_REPLY
or UHID_SET_REPORT_REPLY.
Unfortunatelly, the current code waits for an event of type UHID_GET_REPORT
or UHID_SET_REPORT instead of the reply one.
Add 1 to UHID_GET_REPORT or UHID_SET_REPORT to actually wait for the
reply, and validate the reply.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This makes UHID_START include a "dev_flags" field that describes details
of the hid-device in the kernel. The first flags we introduce describe
whether a given report-type uses numbered reports. This is useful for
transport layers that force report-numbers and therefore might have to
prefix kernel-provided HID-messages with the report-number.
Currently, only HoG needs this and the spec only talks about "global
report numbers". That is, it's a global boolean not a per-type boolean.
However, given the quirks we already have in kernel-space, a per-type
value seems much more appropriate.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
We so far lacked support for hid_hw_raw_request(..., HID_REQ_SET_REPORT);
Add support for it and simply forward the request to user-space. Note that
SET_REPORT is synchronous, just like GET_REPORT, even though it does not
provide any data back besides an error code.
If a transport layer does SET_REPORT asynchronously, they can just ACK it
immediately by writing an uhid_set_report_reply to uhid.
This patch re-uses the synchronous uhid-report infrastructure to query
user-space. Note that this means you cannot run SET_REPORT and GET_REPORT
in parallel. However, that has always been a restriction of HID and due to
its blocking nature, this is just fine. Maybe some future transport layer
supports parallel requests (very unlikely), however, until then lets not
over-complicate things and avoid request-lookup-tables.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
We use strict prefixed in uhid.c:
uhid_char_*: implement char-dev callbacks
uhid_dev_*: implement uhid device management and runtime
uhid_hid_*: implement hid-dev callbacks
uhid_raw_request is an hid callback, so rename it to uhid_hid_raw_request.
While at it, move it closer to it's extracted helpers and keep the same
order as in "struct hid_driver".
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The old hdev->hid_get_raw_report() was broken by design. It was never
clear what kind of HW request it should trigger. Benjamin fixed that with
the core HID cleanup, though we never really adjusted uhid.
Unfortunately, our old UHID_FEATURE command was modelled around the broken
hid_get_raw_report(). We converted it silently to the new GET_REPORT and
nothing broke. Make this explicit by renaming UHID_FEATURE to
UHID_GET_REPORT and UHID_FEATURE_ANSWER to UHID_GET_REPORT_REPLY.
Note that this is 100% ABI compatible to UHID_FEATURE. This is just a
rename. But we have to keep the old definitions around to not break API.
>From now on, UHID_GET_REPORT must trigger a GET_REPORT request on the
user-space hardware layer. All the ambiguity due to the weird "feature"
name should be gone now.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
All accesses to @report_done are protected by qlock (or report-contexts).
No need to use an atomic.
While at it, invert the logic and call it "report_running". This is
similar to the uhid->running field and easier to read.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
All accesses to @report_id are protected by @qlock. No need to use an
atomic.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Avoid hard-coding the target buffer sizes and use sizeof() instead. This
also makes us future-proof to buffer-extensions later on.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Avoid keeping uhid->rd_data and uhid->rd_size set in case
uhid_dev_create2() fails. This is non-critical as we never flip
uhid->running and thus never enter uhid_dev_destroy(). However, it's much
nicer for debugging if pointers are only set if they point to valid data.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Instead of hard-coding the uhid_dev_create() function twice, copy any
create_req into a create2_req structure and forward it.
We allocate uhid_create_req on the stack here, but that should be fine.
Unlike uhid_create2_req it is fairly small (<1KB) and it's only used
temporarily to swap entries. uhid_dev_create2() doesn't access it.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The report-query is blocking, so when user-space destroys a device we have
to wake up any blocking kernel context that is currently in the report-cb.
We used some broken correlation between @report_done and @running so far.
Replace it by a much more obvious use.
We now wake up the report-cb if either @report_done or @running is set.
wake_up() and wait_event() serve as implicit barriers (as they always do)
so no need to use smp_rmb/wmb directly.
Note that @report_done is never reset by anyone but the report-cb, thus
it cannot flip twice while we wait for it. And whenever we set @running,
we afterwards synchronously remove the HID device. Therefore, we wait for
all report-cbs to finish before we return. This way, @running can never
flip to true while we wait for it.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This issue was reported by coccicheck using the semantic patch
at scripts/coccinelle/api/memdup.cocci
Signed-off-by: Benoit Taine <benoit.taine@lip6.fr>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
UHID_CREATE2:
HID report descriptor data (rd_data) is an array in struct uhid_create2_req,
instead of a pointer. Enables use from languages that don't support pointers,
e.g. Python.
UHID_INPUT2:
Data array is the last field of struct uhid_input2_req. Enables userspace to
write only the required bytes to kernel (ev.type + ev.u.input2.size + the part
of the data array that matters), instead of the entire struct uhid_input2_req.
Note:
UHID_CREATE2 increases the total size of struct uhid_event slightly, thus
increasing the size of messages that are queued for userspace. However, this
won't affect the userspace processing of these events.
[Jiri Kosina <jkosina@suse.cz>: adjust to hid_get_raw_report() and
hid_output_raw_report() API changes]
Signed-off-by: Petri Gynther <pgynther@google.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Nobody calls hid_output_raw_report anymore, and nobody should.
We can now remove the various implementation in the different
transport drivers and the declarations.
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
uHID is missing a SET_REPORT protocol implementation, but as
.hid_get_raw_report() as been removed from struct hid_device,
there were no means to access GET_REPORT in uhid.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
David Herrmann
Eric Biggers
Linus Torvalds
Xiongfeng Wang
Al Viro
Jason Gerecke
PrasannaKumar Muralidharan
Roderick Colenbrander
Andy Lutomirski
Benjamin Tissoires
Benoit Taine
Petri Gynther