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Filename Latest commit message Latest commit date
Zheng Yejian fce50a628e media: dvb-usb: Fix unexpected infinite loop in dvb_usb_read_remote_control()
[ Upstream commit 2052138b7da52ad5ccaf74f736d00f39a1c9198c ]

Infinite log printing occurs during fuzz test:

  rc rc1: DViCO FusionHDTV DVB-T USB (LGZ201) as ...
  ...
  dvb-usb: schedule remote query interval to 100 msecs.
  dvb-usb: DViCO FusionHDTV DVB-T USB (LGZ201) successfully initialized ...
  dvb-usb: bulk message failed: -22 (1/0)
  dvb-usb: bulk message failed: -22 (1/0)
  dvb-usb: bulk message failed: -22 (1/0)
  ...
  dvb-usb: bulk message failed: -22 (1/0)

Looking into the codes, there is a loop in dvb_usb_read_remote_control(),
that is in rc_core_dvb_usb_remote_init() create a work that will call
dvb_usb_read_remote_control(), and this work will reschedule itself at
'rc_interval' intervals to recursively call dvb_usb_read_remote_control(),
see following code snippet:

  rc_core_dvb_usb_remote_init() {
    ...
    INIT_DELAYED_WORK(&d->rc_query_work, dvb_usb_read_remote_control);
    schedule_delayed_work(&d->rc_query_work,
                          msecs_to_jiffies(rc_interval));
    ...
  }

  dvb_usb_read_remote_control() {
    ...
    err = d->props.rc.core.rc_query(d);
    if (err)
      err(...)  // Did not return even if query failed
    schedule_delayed_work(&d->rc_query_work,
                          msecs_to_jiffies(rc_interval));
  }

When the infinite log printing occurs, the query callback
'd->props.rc.core.rc_query' is cxusb_rc_query(). And the log is due to
the failure of finding a valid 'generic_bulk_ctrl_endpoint'
in usb_bulk_msg(), see following code snippet:

  cxusb_rc_query() {
    cxusb_ctrl_msg() {
      dvb_usb_generic_rw() {
        ret = usb_bulk_msg(d->udev, usb_sndbulkpipe(d->udev,
                           d->props.generic_bulk_ctrl_endpoint),...);
        if (ret)
          err("bulk message failed: %d (%d/%d)",ret,wlen,actlen);
          ...
      }
  ...
  }

By analyzing the corresponding USB descriptor, it shows that the
bNumEndpoints is 0 in its interface descriptor, but
the 'generic_bulk_ctrl_endpoint' is 1, that means user don't configure
a valid endpoint for 'generic_bulk_ctrl_endpoint', therefore this
'invalid' USB device should be rejected before it calls into
dvb_usb_read_remote_control().

To fix it, we need to add endpoint check for 'generic_bulk_ctrl_endpoint'.
And as Sean suggested, the same check and clear halts should be done for
'generic_bulk_ctrl_endpoint_response'. So introduce
dvb_usb_check_bulk_endpoint() to do it for both of them.

Fixes: 4d43e13f72 ("V4L/DVB (4643): Multi-input patch for DVB-USB device")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-19 05:33:30 +02:00
arch perf/x86/intel/pt: Fix pt_topa_entry_for_page() address calculation 2024-08-19 05:33:29 +02:00
block block: prevent division by zero in blk_rq_stat_sum() 2024-04-13 12:51:38 +02:00
certs
crypto crypto: ecrdsa - Fix module auto-load on add_key 2024-06-16 13:28:51 +02:00
Documentation ASoC: dt-bindings: rt5645: add cbj sleeve gpio property 2024-06-16 13:28:31 +02:00
drivers media: dvb-usb: Fix unexpected infinite loop in dvb_usb_read_remote_control() 2024-08-19 05:33:30 +02:00
fs hfsplus: fix to avoid false alarm of circular locking 2024-08-19 05:33:25 +02:00
include USB: move snd_usb_pipe_sanity_check into the USB core 2024-08-19 05:33:30 +02:00
init init: open /initrd.image with O_LARGEFILE 2024-04-13 12:51:36 +02:00
ipc
kernel perf: Prevent passing zero nr_pages to rb_alloc_aux() 2024-08-19 05:33:29 +02:00
lib mlxsw: spectrum_acl_erp: Fix object nesting warning 2024-08-19 05:33:28 +02:00
LICENSES
mm Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again" 2024-07-18 11:40:51 +02:00
net gss_krb5: Fix the error handling path for crypto_sync_skcipher_setkey 2024-08-19 05:33:30 +02:00
samples media: rename VFL_TYPE_GRABBER to _VIDEO 2024-03-26 18:22:22 -04:00
scripts kconfig: remove wrong expr_trans_bool() 2024-07-27 10:38:29 +02:00
security smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity() 2024-04-13 12:51:22 +02:00
sound USB: move snd_usb_pipe_sanity_check into the USB core 2024-08-19 05:33:30 +02:00
tools selftests: forwarding: devlink_lib: Wait for udev events after reloading 2024-08-19 05:33:30 +02:00
usr
virt KVM: async_pf: Cleanup kvm_setup_async_pf() 2024-05-02 16:18:32 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS iio: stx104: Move to addac subdirectory 2023-08-30 16:27:12 +02:00
Makefile Linux 5.4.281 2024-07-27 10:38:33 +02:00
README

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.