He, Bo
cef0d4948c
There is a race condition that could happen if hid_debug_rdesc_show() is running while hdev is in the process of going away (device removal, system suspend, etc) which could result in NULL pointer dereference: BUG: unable to handle kernel paging request at 0000000783316040 CPU: 1 PID: 1512 Comm: getevent Tainted: G U O 4.19.20-quilt-2e5dc0ac-00029-gc455a447dd55 #1 RIP: 0010:hid_dump_device+0x9b/0x160 Call Trace: hid_debug_rdesc_show+0x72/0x1d0 seq_read+0xe0/0x410 full_proxy_read+0x5f/0x90 __vfs_read+0x3a/0x170 vfs_read+0xa0/0x150 ksys_read+0x58/0xc0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x55/0x110 entry_SYSCALL_64_after_hwframe+0x49/0xbe Grab driver_input_lock to make sure the input device exists throughout the whole process of dumping the rdesc. [jkosina@suse.cz: update changelog a bit] Signed-off-by: he, bo <bo.he@intel.com> Signed-off-by: "Zhang, Jun" <jun.zhang@intel.com> 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.