98375b86c7
The syzbot fuzzer provoked a general protection fault in the hid-prodikeys driver: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.3.0-rc5+ #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event RIP: 0010:pcmidi_submit_output_report drivers/hid/hid-prodikeys.c:300 [inline] RIP: 0010:pcmidi_set_operational drivers/hid/hid-prodikeys.c:558 [inline] RIP: 0010:pcmidi_snd_initialise drivers/hid/hid-prodikeys.c:686 [inline] RIP: 0010:pk_probe+0xb51/0xfd0 drivers/hid/hid-prodikeys.c:836 Code: 0f 85 50 04 00 00 48 8b 04 24 4c 89 7d 10 48 8b 58 08 e8 b2 53 e4 fc 48 8b 54 24 20 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 13 04 00 00 48 ba 00 00 00 00 00 fc ff df 49 8b The problem is caused by the fact that pcmidi_get_output_report() will return an error if the HID device doesn't provide the right sort of output report, but pcmidi_set_operational() doesn't bother to check the return code and assumes the function call always succeeds. This patch adds the missing check and aborts the probe operation if necessary. Reported-and-tested-by: syzbot+1088533649dafa1c9004@syzkaller.appspotmail.com Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@vger.kernel.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.