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  1. 07 Oct, 2019 5 commits
    • A Sun's avatar
      media: mceusb: fix out of bounds read in MCE receiver buffer · e4314864
      A Sun authored 
      Fix multiple cases of out of bounds (OOB) read associated with
MCE device receive/input data handling.

In reference for the OOB cases below, the incoming/read (byte) data
format when the MCE device responds to a command is:
    { cmd_prefix, subcmd, data0, data1, ... }
where cmd_prefix are:
    MCE_CMD_PORT_SYS
    MCE_CMD_PORT_IR
and subcmd examples are:
    MCE_RSP_GETPORTSTATUS
    MCE_RSP_EQIRNUMPORTS
    ...
Response size dynamically depends on cmd_prefix and subcmd.
So data0, data1, ... may or may not be present on input.
Multiple responses may return in a single receiver buffer.

The trigger condition for OOB read is typically random or
corrupt input data that fills the mceusb receiver buffer.

Case 1:

mceusb_handle_command() reads data0 (var hi) and data1 (var lo)
regardless of whether the response includes such data.
If { cmd_prefix, subcmd } is at the end of the receiver buffer,
read past end of buffer occurs.

This case was reported by
KASAN: slab-out-of-bounds Read in mceusb_dev_recv
https://syzkaller.appspot.com/bug?extid=c7fdb6cb36e65f2fe8c9

Fix: In mceusb_handle_command(), change variable hi and lo to
pointers, and dereference only when required.

Case 2:

If response with data is truncated at end of buffer after
{ cmd_prefix, subcmd }, mceusb_handle_command() reads past
end of buffer for data0, data1, ...

Fix: In mceusb_process_ir_data(), check response size with
remaining buffer size before invoking mceusb_handle_command().
+    if (i + ir->rem < buf_len)
            mceusb_handle_command(ir, &ir->buf_in[i - 1]);

Case 3:

mceusb_handle_command() handles invalid/bad response such as
{ 0x??, MCE_RSP_GETPORTSTATUS } of length 2 as a response
{ MCE_CMD_PORT_SYS, MCE_RSP_GETPORTSTATUS, data0, ... }
of length 7. Read OOB occurs for non-existent data0, data1, ...
Cause is mceusb_handle_command() does not check cmd_prefix value.

Fix: mceusb_handle_command() must test both cmd_prefix and subcmd.

Case 4:

mceusb_process_ir_data() receiver parser state SUBCMD is
possible at start (i=0) of receiver buffer resulting in buffer
offset=-1 passed to mceusb_dev_printdata().
Bad offset results in OOB read before start of buffer.

[1214218.580308] mceusb 1-1.3:1.0: rx data[0]: 00 80 (length=2)
[1214218.580323] mceusb 1-1.3:1.0: Unknown command 0x00 0x80
...
[1214218.580406] mceusb 1-1.3:1.0: rx data[14]: 7f 7f (length=2)
[1214218.679311] mceusb 1-1.3:1.0: rx data[-1]: 80 90 (length=2)
[1214218.679325] mceusb 1-1.3:1.0: End of raw IR data
[1214218.679340] mceusb 1-1.3:1.0: rx data[1]: 7f 7f (length=2)

Fix: If parser_state is SUBCMD after processing receiver buffer,
reset parser_state to CMD_HEADER.
In effect, discard cmd_prefix at end of receiver buffer.
In mceusb_dev_printdata(), abort if buffer offset is out of bounds.

Case 5:

If response with data is truncated at end of buffer after
{ cmd_prefix, subcmd }, mceusb_dev_printdata() reads past
end of buffer for data0, data1, ...
while decoding the response to print out.

Fix: In mceusb_dev_printdata(), remove unneeded buffer offset
adjustments (var start and var skip) associated with MCE gen1 header.
Test for truncated MCE cmd response (compare offset+len with buf_len)
and skip decoding of incomplete response.
Move IR data tracing to execute before the truncation test.
Signed-off-by: default avatarA Sun <as1033x@comcast.net>
Signed-off-by: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
      e4314864
    • Sean Young's avatar
      media: rc: increase rc-mm tolerance and add debug message · 81bab3fa
      Sean Young authored 
      Decoding often fails on e.g. redrat3 devices. The dev_dbg() helps
with debugging when decoding does fail.

Cc: Patrick Lerda <patrick9876@free.fr>
Signed-off-by: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
      81bab3fa
    • Sean Young's avatar
      media: rc: mark input device as pointing stick · ce819649
      Sean Young authored 
      libinput refuses pointer movement from rc-core, since it believes it's not
a pointer-type device:

libinput error: event17 - Media Center Ed. eHome Infrared Remote Transceiver (1784:0008): libinput bug: REL_X/Y from a non-pointer device

Fixes: 158bc148 ("media: rc: mce_kbd: input events via rc-core's input device")
Fixes: 0ac5a603 ("media: rc: imon: report mouse events using rc-core's input device")
Cc: stable@vger.kernel.org # 4.20+
Signed-off-by: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
      ce819649
    • Sean Young's avatar
      media: delete unused proc_fs.h include · 6bf33ca2
      Sean Young authored 
      procfs is no longer used anywhere in media.
Signed-off-by: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
      6bf33ca2
    • Sean Young's avatar
      media: saa7164: use debugfs rather than procfs for debugging file · ae5f9737
      Sean Young authored 
      This moves /proc/saa7164 to /sys/kernel/debug/saa7164.
Signed-off-by: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
      ae5f9737
  3. 04 Oct, 2019 3 commits
  5. 02 Oct, 2019 2 commits
  7. 01 Oct, 2019 30 commits
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