Commit graph

5 commits

Author SHA1 Message Date
Edward Adam Davis
04c9d3c8ac media: pvrusb2: fix uaf in pvr2_context_set_notify
[ Upstream commit 0a0b79ea55de8514e1750884e5fec77f9fdd01ee ]

[Syzbot reported]
BUG: KASAN: slab-use-after-free in pvr2_context_set_notify+0x2c4/0x310 drivers/media/usb/pvrusb2/pvrusb2-context.c:35
Read of size 4 at addr ffff888113aeb0d8 by task kworker/1:1/26

CPU: 1 PID: 26 Comm: kworker/1:1 Not tainted 6.8.0-rc1-syzkaller-00046-gf1a27f081c1f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:488
 kasan_report+0xda/0x110 mm/kasan/report.c:601
 pvr2_context_set_notify+0x2c4/0x310 drivers/media/usb/pvrusb2/pvrusb2-context.c:35
 pvr2_context_notify drivers/media/usb/pvrusb2/pvrusb2-context.c:95 [inline]
 pvr2_context_disconnect+0x94/0xb0 drivers/media/usb/pvrusb2/pvrusb2-context.c:272

Freed by task 906:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640
poison_slab_object mm/kasan/common.c:241 [inline]
__kasan_slab_free+0x106/0x1b0 mm/kasan/common.c:257
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inline]
slab_free mm/slub.c:4299 [inline]
kfree+0x105/0x340 mm/slub.c:4409
pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:137 [inline]
pvr2_context_thread_func+0x69d/0x960 drivers/media/usb/pvrusb2/pvrusb2-context.c:158

[Analyze]
Task A set disconnect_flag = !0, which resulted in Task B's condition being met
and releasing mp, leading to this issue.

[Fix]
Place the disconnect_flag assignment operation after all code in pvr2_context_disconnect()
to avoid this issue.

Reported-and-tested-by: syzbot+ce750e124675d4599449@syzkaller.appspotmail.com
Fixes: e5be15c63804 ("V4L/DVB (7711): pvrusb2: Fix race on module unload")
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 08:44:55 +01:00
Arnd Bergmann
f160ec1340 media: pvrusb2: fix pvr2_stream_callback casts
[ Upstream commit 30baa4a96b23add91a87305baaeba82c4e109e1f ]

clang-16 complains about a control flow integrity (KCFI) issue in pvrusb2,
which casts three different prototypes into pvr2_stream_callback:

drivers/media/usb/pvrusb2/pvrusb2-v4l2.c:1070:30: error: cast from 'void (*)(struct pvr2_v4l2_fh *)' to 'pvr2_stream_callback' (aka 'void (*)(void *)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
 1070 |         pvr2_stream_set_callback(sp,(pvr2_stream_callback)pvr2_v4l2_notify,fh);
      |                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/pvrusb2/pvrusb2-context.c:110:6: error: cast from 'void (*)(struct pvr2_context *)' to 'void (*)(void *)' converts to incompatible function type [-Werror,-Wcast-function-type-strict]
  110 |                                         (void (*)(void *))pvr2_context_notify,
      |                                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/media/usb/pvrusb2/pvrusb2-dvb.c:152:6: error: cast from 'void (*)(struct pvr2_dvb_adapter *)' to 'pvr2_stream_callback' (aka 'void (*)(void *)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
  152 |                                  (pvr2_stream_callback) pvr2_dvb_notify, adap);
      |                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Change the functions to actually take a void* argument so the cast is no longer
needed.

Fixes: bb8ce9d9143c ("V4L/DVB (7682): pvrusb2-dvb: finish up stream & buffer handling")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 08:44:54 +01:00
Daniil Dulov
3a301ec9d2 media: pvrusb2: remove redundant NULL check
[ Upstream commit 95ac1210fb2753f968ebce0730d4fbc553c2a3dc ]

Pointer dip->stream cannot be NULL due to a shift, thus remove redundant
NULL check.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: c74e0062684b ("V4L/DVB (5059): Pvrusb2: Be smarter about mode restoration")
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 08:44:54 +01:00
Ricardo B. Marliere
3362732a94 media: pvrusb2: fix use after free on context disconnection
[ Upstream commit ded85b0c0edd8f45fec88783d7555a5b982449c1 ]

Upon module load, a kthread is created targeting the
pvr2_context_thread_func function, which may call pvr2_context_destroy
and thus call kfree() on the context object. However, that might happen
before the usb hub_event handler is able to notify the driver. This
patch adds a sanity check before the invalid read reported by syzbot,
within the context disconnection call stack.

Reported-and-tested-by: syzbot+621409285c4156a009b3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000a02a4205fff8eb92@google.com/

Fixes: e5be15c63804 ("V4L/DVB (7711): pvrusb2: Fix race on module unload")
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Acked-by: Mike Isely <isely@pobox.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 12:12:39 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00