Commit Graph

16 Commits

Author SHA1 Message Date
Edward Adam Davis
1d5f88f053 media: vidtv: Terminating the subsequent process of initialization failure
syzbot reported a slab-use-after-free Read in vidtv_mux_init. [1]

After PSI initialization fails, the si member is accessed again, resulting
in this uaf.

After si initialization fails, the subsequent process needs to be exited.

[1]
BUG: KASAN: slab-use-after-free in vidtv_mux_pid_ctx_init drivers/media/test-drivers/vidtv/vidtv_mux.c:78 [inline]
BUG: KASAN: slab-use-after-free in vidtv_mux_init+0xac2/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:524
Read of size 8 at addr ffff88802fa42acc by task syz.2.37/6059

CPU: 0 UID: 0 PID: 6059 Comm: syz.2.37 Not tainted 6.14.0-rc5-syzkaller #0
Hardware name: Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xc3/0x670 mm/kasan/report.c:521
kasan_report+0xd9/0x110 mm/kasan/report.c:634
vidtv_mux_pid_ctx_init drivers/media/test-drivers/vidtv/vidtv_mux.c:78
vidtv_mux_init+0xac2/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:524
vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194
vidtv_start_feed drivers/media/test-drivers/vidtv/vidtv_bridge.c:239
dmx_section_feed_start_filtering drivers/media/dvb-core/dvb_demux.c:973
dvb_dmxdev_feed_start drivers/media/dvb-core/dmxdev.c:508 [inline]
dvb_dmxdev_feed_restart.isra.0 drivers/media/dvb-core/dmxdev.c:537
dvb_dmxdev_filter_stop+0x2b4/0x3a0 drivers/media/dvb-core/dmxdev.c:564
dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline]
dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246
__fput+0x3ff/0xb70 fs/file_table.c:464
task_work_run+0x14e/0x250 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0xad8/0x2d70 kernel/exit.c:938
do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
__do_sys_exit_group kernel/exit.c:1098 [inline]
__se_sys_exit_group kernel/exit.c:1096 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096
x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f871d58d169
Code: Unable to access opcode bytes at 0x7f871d58d13f.
RSP: 002b:00007fff4b19a788 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f871d58d169
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff4b19a7ec R08: 0000000b4b19a87f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000003
R13: 00000000000927c0 R14: 000000000001d553 R15: 00007fff4b19a840
 </TASK>

Allocated by task 6059:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 vidtv_psi_pat_table_init drivers/media/test-drivers/vidtv/vidtv_psi.c:970
 vidtv_channel_si_init drivers/media/test-drivers/vidtv/vidtv_channel.c:423
 vidtv_mux_init drivers/media/test-drivers/vidtv/vidtv_mux.c:519
 vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194
 vidtv_start_feed drivers/media/test-drivers/vidtv/vidtv_bridge.c:239
 dmx_section_feed_start_filtering drivers/media/dvb-core/dvb_demux.c:973
 dvb_dmxdev_feed_start drivers/media/dvb-core/dmxdev.c:508 [inline]
 dvb_dmxdev_feed_restart.isra.0 drivers/media/dvb-core/dmxdev.c:537
 dvb_dmxdev_filter_stop+0x2b4/0x3a0 drivers/media/dvb-core/dmxdev.c:564
 dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline]
 dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246
 __fput+0x3ff/0xb70 fs/file_table.c:464
 task_work_run+0x14e/0x250 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xad8/0x2d70 kernel/exit.c:938
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096
 x64_sys_call arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6059:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x2c4/0x4d0 mm/slub.c:4757
 vidtv_channel_si_init drivers/media/test-drivers/vidtv/vidtv_channel.c:499
 vidtv_mux_init drivers/media/test-drivers/vidtv/vidtv_mux.c:519
 vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194
 vidtv_start_feed drivers/media/test-drivers/vidtv/vidtv_bridge.c:239
 dmx_section_feed_start_filtering drivers/media/dvb-core/dvb_demux.c:973
 dvb_dmxdev_feed_start drivers/media/dvb-core/dmxdev.c:508 [inline]
 dvb_dmxdev_feed_restart.isra.0 drivers/media/dvb-core/dmxdev.c:537
 dvb_dmxdev_filter_stop+0x2b4/0x3a0 drivers/media/dvb-core/dmxdev.c:564
 dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline]
 dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246
 __fput+0x3ff/0xb70 fs/file_table.c:464
 task_work_run+0x14e/0x250 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xad8/0x2d70 kernel/exit.c:938
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096
 x64_sys_call arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: 3be8037960 ("media: vidtv: add error checks")
Cc: stable@vger.kernel.org
Reported-by: syzbot+0d33ab192bd50b6c91e6@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0d33ab192bd50b6c91e6
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
2025-04-25 15:14:28 +02:00
Colin Ian King
3c0dde35e6 media: [next] media: vidtv: fix a read from an object after it has been freed
Currently the call to vidtv_psi_pat_table_destroy frees the object
m->si.pat however m->si.pat->num_pmt is being accessed after the
free.  Fix this by destroying m->si.pat after the m->si.pmt_secs[]
objects have been freed.

Addresses-Coverity: ("Read from pointer after free")

Reported-by: Cengiz Can <cengiz@kernel.wtf> # sent a similar fix about the same time

Fixes: 039b7caed1 ("media: vidtv: add a PID entry for the NIT table")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-12-02 13:15:07 +01:00
Mauro Carvalho Chehab
bfa4aaebe8 media: vidtv: fix service_id at SDT table
The service_id there should be equal to the one used
on other tables, otherwise, EIT entries won't be valid.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
11f4933f7b media: vidtv: fix service type
As the service currently broadcasts just audio, change the
service type to reflect that.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
039b7caed1 media: vidtv: add a PID entry for the NIT table
On normal TS streams, the NIT table has its own entry at PAT,
but not at PMT.

While here, properly handle alloc problems when creating
PMT entries.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
91a8a240e2 media: vidtv: properly fill EIT service_id
The EIT header ID field should not contain the network ID, but,
instead, the service_id of the program described at EIT.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
b9e09e06e3 media: vidtv: improve EIT data
Place some text at EIT data, and use ISO 8859-15 encoding for
the German letter "ü" (u mit umlat) letter.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
a8bd461ca3 media: vidtv: do some cleanups at the driver
Do some cleanups at the coding style of the driver:
- remove "inline" declarations;
- use reverse xmas-tree for local var declarations;
- Adjust some indent to avoid breaking 80-cols;
- Cleanup some comments.

No functional changes.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
af66e03edd media: vidtv: fix the name of the program
While the original plan was to use the first movement of
the 5th Symphony, it was opted to use the Für Elise song,
instead.

Fix it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:44:19 +01:00
Mauro Carvalho Chehab
3be8037960 media: vidtv: add error checks
Currently, there are not checks if something gets bad during
memory allocation: it will simply use NULL pointers and
crash.

Add error path at the logic which allocates memory for the
MPEG-TS generator code, propagating the errors up to the
vidtv_bridge. Now, if something wents bad, start_streaming
will return an error that userspace can detect:

	ERROR    DMX_SET_PES_FILTER failed (PID = 0x2000): 12 Cannot allocate memory

and the driver doesn't crash.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:43:40 +01:00
Mauro Carvalho Chehab
8922e3931d media: vidtv: reorganize includes
- Place the includes on alphabetical order;
- get rid of asm/byteorder.h;
- add bug.h at vidtv_s302m.c, as it is needed by
  inux/fixp-arith.h

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:41:03 +01:00
Daniel W. S. Almeida
7a7899f6f5 media: vidtv: psi: Implement an Event Information Table (EIT)
Implement an Event Information Table (EIT) as per EN 300 468
5.2.4.

The EIT provides information in chronological order regarding
the events contained within each service.

For now only present event information is supported.

[mchehab+huawei@kernel.org: removed an extra blank line]
Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:39:31 +01:00
Daniel W. S. Almeida
c2f78f0cb2 media: vidtv: psi: add a Network Information Table (NIT)
Add a Network Information Table (NIT) as specified in ETSI EN 300 468.

This table conveys information relating to the physical organization of
the multiplexes carried via a given network and the characteristics of
the network itself.

It is conveyed in the output of vidtv as packets with TS PID of 0x0010

[mchehab+huawei@kernel.org: removed an extra blank line]
Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:37:59 +01:00
Mauro Carvalho Chehab
2f21772961 media: vidtv: cleanup SDT string identifiers
In order to better test userspace applications, add an encoding
for the strings. The original channel string is also too big.
As we're just playing the first compasses of the 5th Beethoven
Symphony, change the service name to just "Beethoven". Also,
add a provider's name. For such purpose, let's point it to
the Linux media community website.

With such changes, the SDT table now looks more like one got
from a real digital TV channel:

SDT
| table_id         0x42
| section_length      44
| one                 2
| zero                1
| syntax              1
| transport_stream_id 1860
| current_next        1
| version             0
| one2                3
| section_number      0
| last_section_number 0
| network_id          65281
| reserved            255
|\
|- service 0x0880
|   EIT schedule          0
|   EIT present following 0
|   free CA mode          0
|   running status        4
|   descriptor length     27
|        0x48: service_descriptor
|           service type  1
|           provider      'LinuxTV.org'
|           name          'Beethoven'
|_  1 services

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:21:17 +02:00
Mauro Carvalho Chehab
9cfb4d36c2 media: vidtv: prefer using dev_foo() instead of pr_foo()
It is better to use the higher level dev_foo() than pr_foo()
for printks.

Change them at vidtv at the more trivial places.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-14 15:47:51 +02:00
Daniel W. S. Almeida
f90cf6079b media: vidtv: add a bridge driver
Digital TV devices consist of several independent hardware components
which are controlled by different drivers.
Each media device is controlled by a group of cooperating drivers with the
bridge driver as the main driver.

This patch adds a bridge driver for the Virtual Digital TV driver [vidtv].

The bridge driver binds to the other drivers, that is, vidtv_tuner and
vidtv_demod and implements the digital demux logic, providing userspace
with a MPEG Transport Stream.

The MPEG related code is split in the following way:

- vidtv_ts: code to work with MPEG TS packets, such as TS headers,
adaptation fields, PCR packets and NULL packets.

- vidtv_psi: this is the PSI generator.
PSI packets contain general information about a MPEG Transport Stream.
A PSI generator is needed so userspace apps can retrieve information
about the Transport Stream and eventually tune into a (dummy) channel.

Because the generator is implemented in a separate file, it can be
reused elsewhere in the media subsystem.

Currently vidtv supports working with 3 PSI tables:
PAT, PMT and SDT.

- vidtv_pes: implements the PES logic to convert encoder data into
MPEG TS packets. These can then be fed into a TS multiplexer and
eventually into userspace.

- vidtv_s302m: implements a S302M encoder to make it possible to
insert PCM audio data in the generated MPEG Transport Stream.

This shall enable passing an audio signal into userspace so it can be
decoded and played by media software.

- vidtv_channels: Implements a 'channel' abstraction

When vidtv boots, it will create some hardcoded channels:

Their services will be concatenated to populate the SDT.
Their programs will be concatenated to populate the PAT
For each program in the PAT, a PMT section will be created
The PMT section for a channel will be assigned its streams.
Every stream will have its corresponding encoder polled to produce TS
packets
These packets may be interleaved by the mux and then delivered to the
bridge

- vidtv_mux - Implements a MPEG TS mux, loosely based on the ffmpeg
implementation

The multiplexer is responsible for polling encoders,
interleaving packets, padding the resulting stream with NULL packets if
necessary and then delivering the resulting TS packets to the bridge
driver so it can feed the demux.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-12 09:43:12 +02:00